# Commands

## bin2sna.py

bin2sna.py converts a binary (raw memory) file into an SZX or Z80 snapshot. For example:

    $ bin2sna.py game.bin

will create a file named game.z80.

If the input file is 128K in length, it is assumed to hold the contents of RAM banks 0-7 in order, and bin2sna.py will write a corresponding 128K snapshot. Otherwise, the `--page` option is required to write a 128K snapshot, and the contents of individual RAM banks may be specified by `--bank` options. If the input file is less than 128K in length and no `--page` option is given, a 48K snapshot is written.

Run bin2sna.py with no arguments to see the list of available options:

    usage: bin2sna.py [options] file.bin [OUTFILE]

    Convert a binary (raw memory) file into an SZX or Z80 snapshot. 'file.bin' may
    be a regular file, or '-' for standard input. If 'OUTFILE' is not given, it
    defaults to the name of the input file with '.bin' replaced by '.z80', or
    'program.z80' if reading from standard input.

    Options:
      --bank N,file         Load RAM bank N (0-7) from the named file. This option
                            may be used multiple times.
      -b BORDER, --border BORDER
                            Set the border colour (default: 7).
      -o ORG, --org ORG     Set the origin address (default: 65536 minus the
                            length of file.bin).
      --page N              Specify the RAM bank (N=0-7) mapped to 49152 (0xC000)
                            in the main input file. This option creates a 128K
                            snapshot.
      -p STACK, --stack STACK
                            Set the stack pointer (default: ORG).
      -P [p:]a[-b[-c]],[^+]v, --poke [p:]a[-b[-c]],[^+]v
                            POKE N,v in RAM bank p for N in {a, a+c, a+2c..., b}.
                            Prefix 'v' with '^' to perform an XOR operation, or
                            '+' to perform an ADD operation. This option may be
                            used multiple times.
      -r name=value, --reg name=value
                            Set the value of a register. Do '--reg help' for more
                            information. This option may be used multiple times.
      -s START, --start START
                            Set the address at which to start execution (default:
                            ORG).
      -S name=value, --state name=value
                            Set a hardware state attribute. Do '--state help' for
                            more information. This option may be used multiple
                            times.
      -V, --version         Show SkoolKit version number and exit.

Version | Changes
--- | ---
10.0 | Added support for setting the MEMPTR register in SZX snapshots
9.1 | Added the `--bank` and `--page` options and support for writing 128K snapshots; the `--poke` option can modify specific RAM banks
9.0 | Added support for writing SZX snapshots; added the `fe` hardware state attribute
8.10 | Added the `issue2` hardware state attribute
8.9 | Added the `tstates` hardware state attribute
6.3 | Added the `--poke` option
6.2 | Added the `--reg` and `--state` options; the `--org`, `--stack` and `--start` options accept a hexadecimal integer prefixed by ‘0x’
5.2 | New

## bin2tap.py

bin2tap.py converts a binary (raw memory) file or a SNA, SZX or Z80 snapshot into a PZX or TAP file. For example:

    $ bin2tap.py game.bin

will create a file called game.tap. By default, the origin address (the address of the first byte of code or data), the start address (the first byte of code to run) and the stack pointer are set to 65536 minus the length of game.bin. These values can be changed by passing options to bin2tap.py. Run it with no arguments to see the list of available options:

    usage: bin2tap.py [options] FILE [OUTFILE]

    Convert a binary (raw memory) file or a SNA, SZX or Z80 snapshot into a PZX or
    TAP file. FILE may be a regular file, or '-' to read a binary file from
    standard input. If OUTFILE is not given, a TAP file is created.

    Options:
      --7ffd N              Add 128K RAM banks to the tape file and write N to
                            port 0x7ffd after they've loaded.
      --banks N[,N...]      Add only these 128K RAM banks to the tape file
                            (default: 0,1,3,4,6,7).
      -b BEGIN, --begin BEGIN
                            Begin conversion at this address (default: ORG for a
                            binary file, 16384 for a snapshot).
      -c N, --clear N       Use a 'CLEAR N' command in the BASIC loader and leave
                            the stack pointer alone.
      -e END, --end END     End conversion at this address.
      --loader ADDR         Place the 128K RAM bank loader at this address
                            (default: CLEAR address + 1).
      -o ORG, --org ORG     Set the origin address for a binary file (default:
                            65536 minus the length of FILE).
      -p STACK, --stack STACK
                            Set the stack pointer (default: BEGIN).
      -s START, --start START
                            Set the start address to JP to (default: BEGIN).
      -S FILE, --screen FILE
                            Add a loading screen to the tape file. FILE may be a
                            snapshot or a 6912-byte SCR file.
      -V, --version         Show SkoolKit version number and exit.

Note that the ROM tape loading routine at 1366 (0x0556) and the load routine used by bin2tap.py together require 14 bytes for stack operations, and so STACK must be at least 16384+14=16398 (0x400E). This means that if ORG is less than 16398, you should use the `-p` option to set the stack pointer to something appropriate. If the main data block (derived from game.bin) overlaps any of the last four bytes of the stack, bin2tap.py will replace those bytes with the values required by the tape loading routine for correct operation upon returning. Stack operations will overwrite the bytes in the address range STACK-14 to STACK-1 inclusive, so those addresses should not be used to store essential code or data.

If the input file contains a program that returns to BASIC, you should use the `--clear` option to add a CLEAR command to the BASIC loader. This option leaves the stack pointer alone, enabling the program to return to BASIC without crashing. The lowest usable address with the `--clear` option on a bare 48K Spectrum is 23972 (0x5DA4) if a loading screen is used, or 23952 (0x5D90) otherwise.

To create a tape file that loads a 128K game, use the `--7ffd`, `--begin` and `--clear` options along with a 128K snapshot or a 128K binary file as input, where:

- `--7ffd` specifies the value to write to port 0x7FFD after all the RAM banks have loaded and before starting the game

- `--begin` specifies the start address of the code/data below 49152 (0xC000) to include on the tape

- `--clear` specifies the address of the CLEAR command in the BASIC loader

By default, the 128K RAM bank loader (which is 39-45 bytes long, depending on the number of RAM banks to load) is placed one above the CLEAR address. Use the `--loader` option to place it at an alternative address. The lowest usable address with the `--clear` option on a bare 128K Spectrum is 23977 (0x5DA9) if a loading screen is used, or 23957 (0x5D95) otherwise.

By default, 128K RAM banks 0, 1, 3, 4, 6 and 7 are added to the tape file. If one or more of these RAM banks are not required, use the `--banks` option to specify a smaller set of RAM banks to add. If none of these RAM banks are required, use `,` (a single comma) as the argument to the `--banks` option. The contents of RAM banks 5 and 2 - from the `--begin` address and up to but not including the `--end` address (if given) - are included in the main code block on the tape.

Version | Changes
--- | ---
9.3 | Added support for writing PZX files
9.1 | Added the `--7ffd`, `--banks` and `--loader` options and support for writing 128K TAP files
8.3 | Added the `--begin` option; the `--end` option applies to raw memory files as well as snapshots
6.2 | The `--clear`, `--end`, `--org`, `--stack` and `--start` options accept a hexadecimal integer prefixed by ‘0x’
5.3 | Added the `--screen` option
5.2 | Added the ability to read a binary file from standard input; added a second positional argument specifying the TAP filename
4.5 | Added the `--clear` and `--end` options, and the ability to convert SNA, SZX and Z80 snapshots
3.4 | Added the `-V` option and the long options
2.2.5 | Added the `-p` option
1.3.1 | New

## rzxinfo.py

rzxinfo.py shows the blocks in or extracts the snapshots from an RZX file. For example:

    $ rzxinfo.py game.rzx

To list the options supported by rzxinfo.py, run it with no arguments:

    usage: rzxinfo.py [options] FILE

    Show the blocks in or extract the snapshots from an RZX file.

    Options:
      --extract      Extract snapshots.
      --frames       Show the contents of every frame.
      -V, --version  Show SkoolKit version number and exit.

Version | Changes
--- | ---
9.2 | New

## rzxplay.py

rzxplay.py plays an RZX file. For example:

    $ rzxplay.py game.rzx

To list the options supported by rzxplay.py, run it with no arguments:

    usage: rzxplay.py [options] FILE [OUTFILE]

    Play an RZX file. If 'OUTFILE' is given, an SZX or Z80 snapshot or an RZX file
    is written after playback has completed.

    Options:
      -c, --cmio       Simulate memory and I/O contention and the MEMPTR register.
      --flags FLAGS    Set playback flags. Do '--flags help' for more information.
      --force          Force playback when an unsupported machine is detected.
      --fps FPS        Run at this many frames per second (default: 50). 0 means
                       maximum speed.
      --map FILE       Log addresses of executed instructions to a file.
      --no-screen      Run without a screen.
      --python         Use the pure Python Z80 simulator.
      --quiet          Don't print progress percentage.
      --scale SCALE    Scale display up by this factor (1-4; default: 2).
      --snapshot FILE  Specify an external snapshot file to start with.
      --stop FRAMES    Stop after playing this many frames.
      --trace FILE     Log executed instructions to a file.
      -V, --version    Show SkoolKit version number and exit.

rzxplay.py can play RZX files that were recorded in 48K, 128K or +2 mode with no peripherals (e.g. Interface 1) attached. If any peripherals are attached, playback may fail. The `--force` option can be used to make rzxplay.py attempt playback of a file that was recorded on an unsupported machine, but it is unlikely to play to the end.

If pygame is installed, rzxplay.py will use it to render the Spectrum’s screen contents at 50 frames per second by default. Use the `--fps` option to change the frame rate. Specifying `--fps 0` makes rzxplay.py run at maximum speed. To disable the screen and make rzxplay.py run even faster, use the `--no-screen` option.

The `--map` option can be used to log the addresses of instructions executed during playback to a file. This file can then be used by sna2ctl.py to produce a control file. If the file specified by the `--map` option already exists, any addresses it contains will be merged with those of the instructions executed.

The `--flags` option sets flags that control the playback of RZX frames when interrupts are enabled. If an RZX file fails to play to completion, setting one or more of these flags may help. `FLAGS` is the sum of the following values, chosen according to the desired outcome:

- 1 - When the last instruction in a frame is either ‘LD A,I’ or ‘LD A,R’, reset bit 2 of the flags register. This is the expected behaviour of a real Z80, but some RZX files fail when this flag is set.

- 2 - When the last instruction in a frame is ‘EI’, and the next frame is a short one (i.e. has a fetch count of 1 or 2), block the interrupt in the next frame. By default, and according to RZX convention, rzxplay.py accepts an interrupt at the start of every frame except the first, regardless of whether the instruction just executed would normally block it. However, some RZX files contain a short frame immediately after an ‘EI’ to indicate that the interrupt should in fact be blocked, and therefore require this flag to be set to play back correctly.

- 4 - Ignore any snapshots after the first one. By default, rzxplay.py will use a snapshot embedded in an RZX file to update its internal state (i.e. memory and registers) before continuing to process the next input recording block. However, some RZX files created by the Fuse emulator do not play correctly under that scheme, and require this flag to be set.

If `OUTFILE` is given, and ends with either ‘.z80’ or ‘.szx’, then a snapshot in the corresponding format is written when playback ends. Similarly, if `OUTFILE` ends with ‘.rzx’, then an RZX file is written when playback ends. However, this makes sense only if `--stop` is used to end playback somewhere in the middle of the input RZX file, otherwise the output RZX file will be empty (i.e. contain no frames).

Version | Changes
--- | ---
10.1 | Added the `--cmio` option; added support for multiple colours in the border area of the screen
10.0 | Added support for ignoring any snapshots after the first one; added a border area to the screen
9.2 | New

## skool2asm.py

skool2asm.py converts a skool file into an ASM file that can be fed to an assembler (see Supported assemblers). For example:

    $ skool2asm.py game.skool > game.asm

skool2asm.py supports many options; run it with no arguments to see a list:

    usage: skool2asm.py [options] FILE

    Convert a skool file into an ASM file and write it to standard output. FILE may
    be a regular file, or '-' for standard input.

    Options:
      -c, --create-labels   Create default labels for unlabelled instructions.
      -D, --decimal         Write the disassembly in decimal.
      -E ADDR, --end ADDR   Stop converting at this address.
      -f N, --fixes N       Apply fixes:
                              N=0: None (default)
                              N=1: @ofix only
                              N=2: @ofix and @bfix
                              N=3: @ofix, @bfix and @rfix (implies -r)
      -F, --force           Force conversion, ignoring @start and @end directives.
      -H, --hex             Write the disassembly in hexadecimal.
      -I p=v, --ini p=v     Set the value of the configuration parameter 'p' to
                            'v'. This option may be used multiple times.
      -l, --lower           Write the disassembly in lower case.
      -p, --package-dir     Show path to skoolkit package directory and exit.
      -P p=v, --set p=v     Set the value of ASM writer property 'p' to 'v'. This
                            option may be used multiple times.
      -q, --quiet           Be quiet.
      -r, --rsub            Apply safe substitutions (@ssub) and relocatability
                            substitutions (@rsub) (implies '-f 1').
      --show-config         Show configuration parameter values.
      -s, --ssub            Apply safe substitutions (@ssub).
      -S ADDR, --start ADDR
                            Start converting at this address.
      -u, --upper           Write the disassembly in upper case.
      --var name=value      Define a variable that can be used by @if and skool
                            macros. This option may be used multiple times.
      -V, --version         Show SkoolKit version number and exit.
      -w, --no-warnings     Suppress warnings.
      -W CLASS, --writer CLASS
                            Specify the ASM writer class to use.

See ASM modes and directives for a description of the `@ssub` and `@rsub` substitution modes, and the `@ofix`, `@bfix` and `@rfix` bugfix modes.

See the @set directive for information on the ASM writer properties that can be set by the `--set` option.

### Configuration

skool2asm.py will read configuration from a file named skoolkit.ini in the current working directory or in ~/.skoolkit, if present. The recognised configuration parameters are:

- `Address` - the format of the default link text for the #R macro when the target address has no label (default: ‘’); this format string recognises the replacement field `address`; if the format string is blank, the address is formatted exactly as it appears in the skool file (without any `$` prefix)

- `Base` - convert addresses and instruction operands to hexadecimal (`16`) or decimal (`10`), or leave them as they are (`0`, the default)

- `Case` - write the disassembly in lower case (`1`) or upper case (`2`), or leave it as it is (`0`, the default)

- `CreateLabels` - create default labels for unlabelled instructions (`1`), or don’t (`0`, the default)

- `EntryLabel` - the format of the default label for the first instruction in a routine or data block (default: `L{address}`)

- `EntryPointLabel` - the format of the default label for an instruction other than the first in a routine or data block (default: `{main}_{index}`)

- `Quiet` - be quiet (`1`) or verbose (`0`, the default)

- `Set-property` - set an ASM writer property value, e.g. `Set-bullet=+` (see the @set directive for a list of available properties)

- `Templates` - file from which to read custom ASM templates

- `Warnings` - show warnings (`1`, the default), or suppress them (`0`)

`EntryLabel` and `EntryPointLabel` are standard Python format strings. `EntryLabel` recognises the following replacement fields:

- `address` - the address of the routine or data block as it appears in the skool file

- `location` - the address of the routine or data block as an integer

`EntryPointLabel` recognises the following replacement fields:

- `address` - the address of the instruction as it appears in the skool file

- `index` - 0 for the first unlabelled instruction in the routine or data block, 1 for the second, etc.

- `location` - the address of the instruction as an integer

- `main` - the label of the first instruction in the routine or data block

Configuration parameters must appear in a `[skool2asm]` section. For example, to make skool2asm.py write the disassembly in hexadecimal with a line width of 120 characters by default (without having to use the `-H` and `-P` options on the command line), add the following section to skoolkit.ini:

    [skool2asm]
    Base=16
    Set-line-width=120

Configuration parameters may also be set on the command line by using the `--ini` option. Parameter values set this way will override any found in skoolkit.ini.

Version | Changes
--- | ---
8.5 | Added the `Address`, `EntryLabel` and `EntryPointLabel` configuration parameters
7.2 | Added the `Templates` configuration parameter and support for ASM templates
7.0 | Non-entry blocks are reproduced verbatim; added the `--force` option
6.4 | Added the `--var` option
6.2 | Added the `--show-config` option; the `--end` and `--start` options accept a hexadecimal integer prefixed by ‘0x’
6.1 | Configuration is read from skoolkit.ini if present; added the `--ini` option
5.0 | Added the `--set` option
4.5 | Added the `--start` and `--end` options
4.1 | Added the `--writer` option
3.4 | Added the `-V` and `-p` options and the long options
2.2.2 | Added the ability to read a skool file from standard input
2.1.1 | Added the `-u`, `-D` and `-H` options
1.1 | Added the `-c` option

## skool2bin.py

skool2bin.py converts a skool file into a binary (raw memory) file. For example:

    $ skool2bin.py game.skool

To list the options supported by skool2bin.py, run it with no arguments:

    usage: skool2bin.py [options] file.skool [file.bin]

    Convert a skool file into a binary (raw memory) file. 'file.skool' may be a
    regular file, or '-' for standard input. If 'file.bin' is not given, it
    defaults to the name of the input file with '.skool' replaced by '.bin'.
    'file.bin' may be a regular file, or '-' for standard output.

    Options:
      -B, --banks           Process @bank directives and write RAM banks 0-7 to a
                            128K file.
      -b, --bfix            Apply @ofix and @bfix directives.
      -d, --data            Process @defb, @defs and @defw directives.
      -E ADDR, --end ADDR   Stop converting at this address.
      -I p=v, --ini p=v     Set the value of the configuration parameter 'p' to
                            'v'. This option may be used multiple times.
      -i, --isub            Apply @isub directives.
      -o, --ofix            Apply @ofix directives.
      -r, --rsub            Apply @isub, @ssub and @rsub directives (implies
                            --ofix).
      -R, --rfix            Apply @ofix, @bfix and @rfix directives (implies
                            --rsub).
      --show-config         Show configuration parameter values.
      -s, --ssub            Apply @isub and @ssub directives.
      -S ADDR, --start ADDR
                            Start converting at this address.
      -v, --verbose         Show info on each converted instruction.
      -V, --version         Show SkoolKit version number and exit.
      -w, --no-warnings     Suppress warnings.

The `--verbose` option shows information on each converted instruction, such as whether it was inserted before or after another instruction (by a `@*sub` or `@*fix` directive), and its original address (if it was relocated by the insertion, removal or replacement of other instructions). For example:

    40000 9C40 > XOR A
    40001 9C41 | LD HL,40006   : 40000 9C40 LD HL,40003
    40004 9C44 + JR 40006      :            JR 40003
    40006 9C46   RET           : 40003 9C43 RET

This output shows that:

- The instruction at 40000 (XOR A) was inserted before (`>`) another instruction

- The instruction at 40001 (LD HL,40006) overwrote (`|`) the instruction(s) originally at 40000, and had its operand changed from 40003 (because the instruction originally at that address was relocated to 40006)

- The instruction at 40004 (JR 40006) was inserted after (`+`) another instruction, and also had its operand changed from 40003

- The instruction at 40006 (RET) was originally at 40003 (before other instructions were inserted, removed or replaced)

### Configuration

skool2bin.py will read configuration from a file named skoolkit.ini in the current working directory or in ~/.skoolkit, if present. The recognised configuration parameters are:

- `Banks` - process @bank directives and write RAM banks 0-7 to a 128K file (`1`), or don’t (`0`, the default)

- `Data` - process @defb, @defs and @defw directives (`1`), or don’t (`0`, the default)

- `PadLeft` - address at which to start padding the output on the left with zeroes; the default value is `65536`, which produces no padding

- `PadRight` - address at which to stop padding the output on the right with zeroes; the default value is `0`, which produces no padding

- `Verbose` - show info on each converted instruction (`1`), or don’t (`0`, the default)

- `Warnings` - show warnings (`1`, the default), or suppress them (`0`)

Configuration parameters must appear in a `[skool2bin]` section. For example, to make skool2bin.py suppress warnings (without having to use the `-w` option on the command line), add the following section to skoolkit.ini:

    [skool2bin]
    Warnings=0

Configuration parameters may also be set on the command line by using the `--ini` option. Parameter values set this way will override any found in skoolkit.ini.

Version | Changes
--- | ---
9.4 | Configuration is read from skoolkit.ini if present; added the `--ini` and `--show-config` options; added support for padding the output with zeroes
9.1 | Added the `--banks` option
8.1 | Added the `--data`, `--rsub`, `--rfix`, `--verbose` and `--no-warnings` options
7.0 | @if directives are processed
6.2 | The `--end` and `--start` options accept a hexadecimal integer prefixed by ‘0x’
6.1 | Added the ability to assemble instructions whose operands contain arithmetic expressions
5.2 | Added the ability to write the binary file to standard output
5.1 | Added the `--bfix`, `--ofix` and `--ssub` options
5.0 | New

## skool2ctl.py

skool2ctl.py converts a skool file into a control file. For example:

    $ skool2ctl.py game.skool > game.ctl

In addition to block types and addresses, game.ctl will contain block titles, block descriptions, registers, mid-block comments, block start and end comments, sub-block types and addresses, instruction-level comments, non-entry blocks, and some ASM directives.

To list the options supported by skool2ctl.py, run it with no arguments:

    usage: skool2ctl.py [options] FILE

    Convert a skool file into a control file and write it to standard output. FILE
    may be a regular file, or '-' for standard input.

    Options:
      -b, --preserve-base   Preserve the base of decimal and hexadecimal values in
                            instruction operands and DEFB/DEFM/DEFS/DEFW statements.
      -E ADDR, --end ADDR   Stop converting at this address.
      -h, --hex             Write addresses in upper case hexadecimal format.
      -I p=v, --ini p=v     Set the value of the configuration parameter 'p' to
                            'v'. This option may be used multiple times.
      -k, --keep-lines      Preserve line breaks in comments.
      -l, --hex-lower       Write addresses in lower case hexadecimal format.
      --show-config         Show configuration parameter values.
      -S ADDR, --start ADDR
                            Start converting at this address.
      -V, --version         Show SkoolKit version number and exit.
      -w X, --write X       Write only these elements, where X is one or more of:
                              a = ASM directives
                              b = block types and addresses
                              t = block titles
                              d = block descriptions
                              r = registers
                              m = mid-block comments and block start/end comments
                              s = sub-block types and addresses
                              c = instruction-level comments
                              n = non-entry blocks

### Configuration

skool2ctl.py will read configuration from a file named skoolkit.ini in the current working directory or in ~/.skoolkit, if present. The recognised configuration parameters are:

- `Hex` - write addresses in decimal (`0`, the default), lower case hexadecimal (`1`), or upper case hexadecimal (`2`)

- `KeepLines` - preserve line breaks in comments (`1`), or don’t (`0`, the default)

- `PreserveBase` - preserve the base of decimal and hexadecimal values in instruction operands and DEFB/DEFM/DEFS/DEFW statements (`1`), or don’t (`0`, the default)

Configuration parameters must appear in a `[skool2ctl]` section. For example, to make skool2ctl.py write upper case hexadecimal addresses by default (without having to use the `-h` option on the command line), add the following section to skoolkit.ini:

    [skool2ctl]
    Hex=2

Configuration parameters may also be set on the command line by using the `--ini` option. Parameter values set this way will override any found in skoolkit.ini.

Version | Changes
--- | ---
7.2 | Configuration is read from skoolkit.ini if present; added the `--ini`, `--show-config` and `--keep-lines` options
7.0 | Added support for the ‘n’ identifier in the `--write` option
6.2 | The `--end` and `--start` options accept a hexadecimal integer prefixed by ‘0x’
6.0 | Added support for the ‘a’ identifier in the `--write` option
5.1 | A terminal `i` directive is appended if the skool file ends before 65536
4.5 | Added the `--start` and `--end` options
4.4 | Added the `--hex-lower` option
3.7 | Added the `--preserve-base` option
3.4 | Added the `-V` option and the long options
2.4 | Added the ability to preserve some ASM directives
2.2.2 | Added the ability to read a skool file from standard input
2.0.6 | Added the `-h` option
1.1 | New

## skool2html.py

skool2html.py converts a skool file (and its associated ref files, if any exist) into a browsable disassembly in HTML format.

For example:

    $ skool2html.py game.skool

will convert the file game.skool into a bunch of HTML files. If any files named game*.ref (e.g. game.ref, game-bugs.ref, game-pokes.ref and so on) also exist in the same directory as game.skool, they will be used to provide further information to the conversion process, along with any extra files named in the `RefFiles` parameter in the [Config] section, and any other ref files named on the command line.

skool2html.py supports several options; run it with no arguments to see a list:

    usage: skool2html.py [options] SKOOLFILE [REFFILE...]

    Convert a skool file and ref files to HTML. SKOOLFILE may be a regular file, or
    '-' for standard input.

    Options:
      -1, --asm-one-page    Write all routines and data blocks to a single page.
      -a, --asm-labels      Use ASM labels.
      -c S/L, --config S/L  Add the line 'L' to the ref file section 'S'. This
                            option may be used multiple times.
      -C, --create-labels   Create default labels for unlabelled instructions.
      -d DIR, --output-dir DIR
                            Write files in this directory (default is '.').
      -D, --decimal         Write the disassembly in decimal.
      -H, --hex             Write the disassembly in hexadecimal.
      -I p=v, --ini p=v     Set the value of the configuration parameter 'p' to
                            'v'. This option may be used multiple times.
      -j NAME, --join-css NAME
                            Concatenate CSS files into a single file with this name.
      -l, --lower           Write the disassembly in lower case.
      -o, --rebuild-images  Overwrite existing image files.
      -O, --rebuild-audio   Overwrite existing audio files.
      -p, --package-dir     Show path to skoolkit package directory and exit.
      -P PAGES, --pages PAGES
                            Write only these pages (when using '--write P').
                            PAGES is a comma-separated list of page IDs.
      -q, --quiet           Be quiet.
      -r PREFIX, --ref-sections PREFIX
                            Show default ref file sections whose names start with
                            PREFIX and exit.
      -R, --ref-file        Show the entire default ref file and exit.
      -s, --search-dirs     Show the locations skool2html.py searches for resources.
      -S DIR, --search DIR  Add this directory to the resource search path. This
                            option may be used multiple times.
      --show-config         Show configuration parameter values.
      -t, --time            Show timings.
      -T THEME, --theme THEME
                            Use this CSS theme. This option may be used multiple
                            times.
      -u, --upper           Write the disassembly in upper case.
      --var name=value      Define a variable that can be used by @if and skool
                            macros. This option may be used multiple times.
      -V, --version         Show SkoolKit version number and exit.
      -w X, --write X       Write only these files, where X is one or more of:
                              d = Disassembly files   o = Other code
                              i = Disassembly index   P = Other pages
                              m = Memory maps
      -W CLASS, --writer CLASS
                            Specify the HTML writer class to use; shorthand for
                            '--config Config/HtmlWriterClass=CLASS'.

skool2html.py searches the following directories for CSS files, JavaScript files, font files, and files listed in the [Resources] section of the ref file:

- The directory that contains the skool file named on the command line

- The current working directory

- ./resources

- ~/.skoolkit

- $PACKAGE_DIR/resources

- Any other directories specified by the `-S`/`--search` option

where $PACKAGE_DIR is the directory in which the skoolkit package is installed (as shown by `skool2html.py -p`). When you need a reminder of these locations, run `skool2html.py -s`.

The `-T` option sets the CSS theme. For example, if game.ref specifies the CSS files to use thus:

    [Game]
    StyleSheet=skoolkit.css;game.css

then:

    $ skool2html.py -T dark -T wide game.skool

will use the following CSS files, if they exist, in the order listed:

- skoolkit.css

- skoolkit-dark.css

- skoolkit-wide.css

- game.css

- game-dark.css

- game-wide.css

- dark.css

- wide.css

### Configuration

skool2html.py will read configuration from a file named skoolkit.ini in the current working directory or in ~/.skoolkit, if present. The recognised configuration parameters are:

- `AsmLabels` - use ASM labels (`1`), or don’t (`0`, the default)

- `AsmOnePage` - write all routines and data blocks to a single page (`1`), or to multiple pages (`0`, the default)

- `Base` - convert addresses and instruction operands to hexadecimal (`16`) or decimal (`10`), or leave them as they are (`0`, the default)

- `Case` - write the disassembly in lower case (`1`) or upper case (`2`), or leave it as it is (`0`, the default)

- `CreateLabels` - create default labels for unlabelled instructions (`1`), or don’t (`0`, the default)

- `EntryLabel` - the format of the default label for the first instruction in a routine or data block (default: `L{address}`)

- `EntryPointLabel` - the format of the default label for an instruction other than the first in a routine or data block (default: `{main}_{index}`)

- `JoinCss` - if specified, concatenate CSS files into a single file with this name

- `OutputDir` - write files in this directory (default: `.`)

- `Quiet` - be quiet (`1`) or verbose (`0`, the default)

- `RebuildAudio` - overwrite existing audio files (`1`), or leave them alone (`0`, the default)

- `RebuildImages` - overwrite existing image files (`1`), or leave them alone (`0`, the default)

- `Search` - directory to add to the resource search path; to specify two or more directories, separate them with commas

- `Theme` - CSS theme to use; to specify two or more themes, separate them with commas

- `Time` - show timings (`1`), or don’t (`0`, the default)

`EntryLabel` and `EntryPointLabel` are standard Python format strings. `EntryLabel` recognises the following replacement fields:

- `address` - the address of the routine or data block as it appears in the skool file

- `location` - the address of the routine or data block as an integer

`EntryPointLabel` recognises the following replacement fields:

- `address` - the address of the instruction as it appears in the skool file

- `index` - 0 for the first unlabelled instruction in the routine or data block, 1 for the second, etc.

- `location` - the address of the instruction as an integer

- `main` - the label of the first instruction in the routine or data block

Configuration parameters must appear in a `[skool2html]` section. For example, to make skool2html.py use ASM labels and write the disassembly in hexadecimal by default (without having to use the `-H` and `-a` options on the command line), add the following section to skoolkit.ini:

    [skool2html]
    AsmLabels=1
    Base=16

Configuration parameters may also be set on the command line by using the `--ini` option. Parameter values set this way will override any found in skoolkit.ini.

Version | Changes
--- | ---
8.7 | Added the `--rebuild-audio` option and the `RebuildAudio` configuration parameter
8.5 | Added the `EntryLabel` and `EntryPointLabel` configuration parameters
7.0 | Writes a single disassembly from the skool file given by the first positional argument
6.4 | Added the `--var` option
6.2 | Added the `--show-config` option
6.1 | Configuration is read from skoolkit.ini if present; added the `--ini` option
5.4 | Added the `--asm-one-page` option
5.0 | The `--theme` option also looks for a CSS file whose base name matches the theme name
4.1 | Added the `--search` and `--writer` options
4.0 | Added the `--ref-sections` and `--ref-file` options
3.6 | Added the `--join-css` and `--search-dirs` options
3.5 | Added support for multiple CSS themes
3.4 | Added the `-a` and `-C` options and the long options
3.3.2 | Added $PACKAGE_DIR/resources to the search path; added the `-p` and `-T` options
3.2 | Added ~/.skoolkit to the search path
3.1 | Added the `-c` option
3.0.2 | No longer shows timings by default; added the `-t` option
2.3.1 | Added support for reading multiple ref files per disassembly
2.2.2 | Added the ability to read a skool file from standard input
2.2 | No longer writes the Skool Daze and Back to Skool disassemblies by default; added the `-d` option
2.1.1 | Added the `-l`, `-u`, `-D` and `-H` options
2.1 | Added the `-o` and `-P` options
1.4 | Added the `-V` option

## sna2ctl.py

sna2ctl.py generates a control file for a binary (raw memory) file or a SNA, SZX or Z80 snapshot. For example:

    $ sna2ctl.py game.z80 > game.ctl

Now game.ctl can be used by sna2skool.py to convert game.z80 into a skool file split into blocks of code and data.

sna2ctl.py supports several options; run it with no arguments to see a list:

    usage: sna2ctl.py [options] FILE

    Generate a control file for a binary (raw memory) file or a SNA, SZX or Z80
    snapshot. FILE may be a regular file, or '-' for standard input.

    Options:
      -C, --comments        Generate instruction comments.
      -e ADDR, --end ADDR   Stop at this address (default=65536).
      -h, --hex             Write upper case hexadecimal addresses.
      -I p=v, --ini p=v     Set the value of the configuration parameter 'p' to
                            'v'. This option may be used multiple times.
      -l, --hex-lower       Write lower case hexadecimal addresses.
      -m FILE, --map FILE   Use FILE as a code execution map.
      -o ADDR, --org ADDR   Specify the origin address of a binary file (default:
                            65536 - length).
      -p PAGE, --page PAGE  Specify the page (0-7) of a 128K snapshot to map to
                            49152-65535.
      -r, --handle-rst      Handle RST instruction arguments.
      --show-config         Show configuration parameter values.
      -s ADDR, --start ADDR
                            Start at this address.
      -V, --version         Show SkoolKit version number and exit.

If the input filename does not end with ‘.sna’, ‘.szx’ or ‘.z80’, it is assumed to be a binary file.

The `-m` option may be used to specify a code execution map to use when generating a control file. The supported file formats are:

- Files created by the `--map` option of rzxplay.py or trace.py

- Profiles created by the Fuse emulator

- Code execution logs created by the SpecEmu, Spud and Zero emulators

- Map files created by the SpecEmu and Z80 emulators

If the file specified by the `-m` option is 8192 bytes long, it is assumed to be a Z80 map file; if it is 65536 bytes long, it is assumed to be a SpecEmu map file; otherwise it is assumed to be in one of the other supported formats.

The `--handle-rst` option activates the RST handler. When this handler identifies the byte/word argument(s) of an RST instruction, a B directive or W directive is generated accordingly.

### Configuration

sna2ctl.py will read configuration from a file named skoolkit.ini in the current working directory or in ~/.skoolkit, if present. The recognised configuration parameters are:

- `Comments` - generate instruction comments (`1`), or don’t (`0`, the default)

- `Dictionary` - the name of a file containing a list of allowed words, one per line; if specified, a string of characters will be marked as text only if it contains at least one of the words in this file

- `HandleRST` - activate the RST handler (`1`), or don’t (`0`, the default)

- `Hex` - write addresses in decimal (`0`, the default), lower case hexadecimal (`1`), or upper case hexadecimal (`2`)

- `TextChars` - characters eligible for being marked as text (default: letters, digits, space, and the following non-alphanumeric characters: `!"$%&\'()*+,-./:;<=>?[]`)

- `TextMinLengthCode` - the minimum length of a string of characters eligible for being marked as text in a block identified as code (default: `12`)

- `TextMinLengthData` - the minimum length of a string of characters eligible for being marked as text in a block identified as data (default: `3`)

Configuration parameters must appear in a `[sna2ctl]` section. For example, to make sna2ctl.py write upper case hexadecimal addresses by default (without having to use the `-h` option on the command line), add the following section to skoolkit.ini:

    [sna2ctl]
    Hex=2

Configuration parameters may also be set on the command line by using the `--ini` option. Parameter values set this way will override any found in skoolkit.ini.

Version | Changes
--- | ---
9.6 | Added the `--handle-rst` option and the `HandleRST` configuration parameter
9.5 | Added the `--comments` option and the `Comments` configuration parameter
9.2 | Added support for reading code execution maps produced by rzxplay.py
7.2 | Added the `Dictionary` configuration parameter
7.1 | Configuration is read from skoolkit.ini if present; added the `--ini` and `--show-config` options
7.0 | New

## sna2img.py

sna2img.py converts the screenshot or other graphic data in a binary (raw memory) file, SCR file, skool file, or SNA/SZX/Z80 snapshot into a PNG file. For example:

    $ sna2img.py game.scr

will create a file named game.png.

To list the options supported by sna2img.py, run it with no arguments:

    usage: sna2img.py [options] INPUT [OUTPUT]

    Convert a Spectrum screenshot or other graphic data into a PNG file. INPUT may
    be a binary (raw memory) file, a SCR file, a skool file, or a SNA, SZX or Z80
    snapshot.

    Options:
      -b, --bfix            Parse a skool file in @bfix mode.
      -B, --binary          Read the input as a binary (raw memory) file.
      -e MACRO, --expand MACRO
                            Expand a #FONT, #SCR, #UDG or #UDGARRAY macro. The '#'
                            prefix may be omitted.
      -f N, --flip N        Flip the image horizontally (N=1), vertically (N=2),
                            or both (N=3).
      -i, --invert          Invert video for cells that are flashing.
      -m src,size,dest, --move src,size,dest
                            Move a block of bytes of the given size from src to
                            dest. This option may be used multiple times.
      -n, --no-animation    Do not animate flashing cells.
      -o X,Y, --origin X,Y  Top-left crop at (X,Y).
      -O ORG, --org ORG     Set the origin address of a binary file (default:
                            65536 minus the length of the file).
      -p a[-b[-c]],[^+]v, --poke a[-b[-c]],[^+]v
                            POKE N,v for N in {a, a+c, a+2c..., b}. Prefix 'v'
                            with '^' to perform an XOR operation, or '+' to
                            perform an ADD operation. This option may be used
                            multiple times.
      -r N, --rotate N      Rotate the image 90*N degrees clockwise.
      -s SCALE, --scale SCALE
                            Set the scale of the image (default=1).
      -S WxH, --size WxH    Crop to this width and height (in tiles).
      -V, --version         Show SkoolKit version number and exit.

Version | Changes
--- | ---
6.2 | Added the `--binary` and `--org` options and the ability to read binary (raw memory) files; the `--move` and `--poke` options accept hexadecimal integers prefixed by ‘0x’
6.1 | Added the ability to read skool files; added the `--bfix` and `--move` options
6.0 | Added the `--expand` option
5.4 | New

## sna2skool.py

sna2skool.py converts a binary (raw memory) file or a SNA, SZX or Z80 snapshot into a skool file. For example:

    $ sna2skool.py game.z80 > game.skool

Now game.skool can be converted into a browsable HTML disassembly using skool2html.py, or into an assembler-ready ASM file using skool2asm.py.

sna2skool.py supports several options; run it with no arguments to see a list:

    usage: sna2skool.py [options] FILE

    Convert a binary (raw memory) file or a SNA, SZX or Z80 snapshot into a skool
    file. FILE may be a regular file, or '-' for standard input.

    Options:
      -c PATH, --ctl PATH   Specify a control file to use, or a directory from
                            which to read control files. PATH may be '-' for
                            standard input, or '0' to use no control file. This
                            option may be used multiple times.
      -C, --comments        Generate instruction comments.
      -d SIZE, --defb SIZE  Disassemble as DEFB statements of this size.
      -e ADDR, --end ADDR   Stop disassembling at this address (default: 65536).
      -H, --hex             Write hexadecimal addresses and operands in the
                            disassembly.
      -I p=v, --ini p=v     Set the value of the configuration parameter 'p' to
                            'v'. This option may be used multiple times.
      -l, --lower           Write the disassembly in lower case.
      -o ADDR, --org ADDR   Specify the origin address of a binary (.bin) file
                            (default: 65536 - length).
      -p PAGE, --page PAGE  Specify the page (0-7) of a 128K snapshot to map to
                            49152-65535.
      -r, --handle-rst      Handle RST instruction arguments.
      --show-config         Show configuration parameter values.
      -s ADDR, --start ADDR
                            Start disassembling at this address.
      -V, --version         Show SkoolKit version number and exit.
      -w W, --line-width W  Set the maximum line width of the skool file (default:
                            79).

If the input filename does not end with ‘.sna’, ‘.szx’ or ‘.z80’, it is assumed to be a binary file.

By default, any files whose names start with the input filename (minus the ‘.bin’, ‘.sna’, ‘.szx’ or ‘.z80’ suffix, if any) and end with ‘.ctl’ will be used as control files.

There are three options and configuration parameters that control whether sna2skool.py generates a comment for an instruction that has no comment defined in a control file. They are mutually exclusive and operate in the following order:

- the `--comments` option or `Comments` configuration parameter (uses the comment generator component)

- the `Text` configuration parameter (shows byte values as ASCII text)

- the `Timings` configuration parameter (shows instruction timings)

The `--handle-rst` option activates the RST handler. When this handler identifies the byte/word argument(s) of an RST instruction, a DEFB/DEFW statement is produced accordingly. This is useful only if no control file is used, or if the control file does not already contain `B` or `W` directives for RST instruction arguments.

### Configuration

sna2skool.py will read configuration from a file named skoolkit.ini in the current working directory or in ~/.skoolkit, if present. The recognised configuration parameters are:

- `Base` - write addresses and instruction operands in hexadecimal (`16`) or decimal (`10`, the default)

- `Case` - write the disassembly in lower case (`1`) or upper case (`2`, the default)

- `Comments` - generate instruction comments (`1`), or don’t (`0`, the default)

- `CommentWidthMin` - minimum width of the instruction comment field in the skool file (default: `10`)

- `DefbSize` - maximum number of bytes in a DEFB statement (default: `8`)

- `DefmSize` - maximum number of characters in a DEFM statement (default: `65`)

- `DefwSize` - maximum number of words in a DEFW statement (default: `1`)

- `EntryPointRef` - template used to format the comment for an entry point with exactly one referrer (default: `This entry point is used by the routine at {ref}.`)

- `EntryPointRefs` - template used to format the comment for an entry point with two or more referrers (default: `This entry point is used by the routines at {refs} and {ref}.`)

- `HandleRST` - activate the RST handler (`1`), or don’t (`0`, the default)

- `InstructionWidth` - minimum width of the instruction field in the skool file (default: `13`)

- `LineWidth` - maximum line width of the skool file (default: `79`)

- `ListRefs` - when to add a comment that lists routine or entry point referrers: never (`0`), if no other comment is defined at the entry point (`1`, the default), or always (`2`)

- `Opcodes` - comma-separated list of values specifying additional opcode sequences to disassemble (see below)

- `Ref` - template used to format the comment for a routine with exactly one referrer (default: `Used by the routine at {ref}.`)

- `RefFormat` - template used to format referrers in the `{ref}` and `{refs}` fields of the `Ref` and `Refs` templates (default: `#R{address}`); the replacement field `address` is the address of the referrer formatted as a decimal or hexadecimal number in accordance with the `Base` and `Case` configuration parameters

- `Refs` - template used to format the comment for a routine with two or more referrers (default: `Used by the routines at {refs} and {ref}.`)

- `Semicolons` - block types (`b`, `c`, `g`, `i`, `s`, `t`, `u`, `w`) in which comment semicolons are written for instructions that have no comment (default: `c`)

- `Text` - show ASCII text in the comment fields (`1`), or don’t (`0`, the default)

- `Timings` - show instruction timings in the comment fields (`1`), or don’t (`0`, the default)

- `Title-b` - template used to format the title for an untitled ‘b’ block (default: `Data block at {address}`)

- `Title-c` - template used to format the title for an untitled ‘c’ block (default: `Routine at {address}`)

- `Title-g` - template used to format the title for an untitled ‘g’ block (default: `Game status buffer entry at {address}`)

- `Title-i` - template used to format the title for an untitled ‘i’ block (default: `Ignored`)

- `Title-s` - template used to format the title for an untitled ‘s’ block (default: `Unused`)

- `Title-t` - template used to format the title for an untitled ‘t’ block (default: `Message at {address}`)

- `Title-u` - template used to format the title for an untitled ‘u’ block (default: `Unused`)

- `Title-w` - template used to format the title for an untitled ‘w’ block (default: `Data block at {address}`)

- `Wrap` - disassemble an instruction that wraps around the 64K boundary (`1`), or don’t (`0`, the default)

The `Opcodes` list is empty by default, but may contain any of the following values:

- `ED63` - LD (nn),HL (4-byte variant)

- `ED6B` - LD HL,(nn) (4-byte variant)

- `ED70` - IN F,(C)

- `ED71` - OUT (C),0

- `IM` - IM 0/1/2 variants (ED followed by 4E/66/6E/76/7E)

- `NEG` - NEG variants (ED followed by 4C/54/5C/64/6C/74/7C)

- `RETN` - RETN variants (ED followed by 55/5D/65/6D/75/7D)

- `XYCB` - undocumented instructions with DDCB or FDCB opcode prefixes (see below)

- `ALL` - all of the above

When `XYCB` is in the list, the following instructions are disassembled (where ‘XY’ is IX or IY, and ‘r’ is B, C, D, E, H, L or A):

- RLC (XY+d),r

- RRC (XY+d),r

- RL (XY+d),r

- RR (XY+d),r

- SLA (XY+d),r

- SRA (XY+d),r

- SLL (XY+d),r

- SRL (XY+d),r

- BIT n,(XY+d) (variants)

- RES n,(XY+d),r

- SET n,(XY+d),r

Whenever an instruction with a variant opcode sequence is disassembled, sna2skool.py will insert a @bytes directive into the skool file (if one is not already provided by a control file) to ensure that the instruction assembles back to the same byte values when processed by skool2asm.py, skool2html.py or skool2bin.py.

Also note that if your skool file contains any non-standard instructions (such as ‘IN F,(C)’) or instructions that derive from variant opcode sequences (such as ‘BIT 0,(IX+0)’ from DDCB0040 instead of the standard DDCB0046), care must be taken when using an assembler on the output of skool2asm.py to ensure that instructions not only assemble successfully, but also assemble back to the original byte values, if desired. The @isub directive may be used for this purpose; for example:

    @isub=DEFB 221,203,0,64 ; This is BIT 0,(IX+0)
     40000 BIT 0,(IX+0) ; The opcode sequence here is DDCB0040

Configuration parameters must appear in a `[sna2skool]` section. For example, to make sna2skool.py generate hexadecimal skool files with a line width of 120 characters by default (without having to use the `-H` and `-w` options on the command line), add the following section to skoolkit.ini:

    [sna2skool]
    Base=16
    LineWidth=120

Configuration parameters may also be set on the command line by using the `--ini` option. Parameter values set this way will override any found in skoolkit.ini.

Version | Changes
--- | ---
9.6 | Added the `--handle-rst` option and the `HandleRST` configuration parameter
9.5 | Added the `--comments` option and the `Comments` configuration parameter
9.3 | Added the `Opcodes` configuration parameter
8.7 | Added the `--defb` option and the `Timings` configuration parameter
8.5 | Added the `Wrap` configuration parameter and the ability to disassemble an instruction that wraps around the 64K boundary; added the `RefFormat` configuration parameter
8.4 | Changed the default value of the `DefmSize` configuration parameter from 66 to 65
8.3 | Added support for reading control files from a directory (`--ctl DIR`)
8.1 | Added support for ignoring default control files (`--ctl 0`)
8.0 | Added the `DefwSize` configuration parameter
7.1 | Added support for reading multiple default control files, and for using the `--ctl` option multiple times; added the `CommentWidthMin`, `InstructionWidth` and `Semicolons` configuration parameters
7.0 | The short option for `--lower` is `-l`; the long option for `-H` is `--hex`
6.2 | Added the `--show-config` option; the `--end`, `--org` and `--start` options accept a hexadecimal integer prefixed by ‘0x’
6.1 | Configuration is read from skoolkit.ini if present; added the `--ini` option
4.4 | Added the `--end` option
4.3 | Added the `--line-width` option
3.4 | Added the `-V` option and the long options, and the ability to add a comment listing referrers at every routine entry point
3.3 | Added the ability to read 128K SNA snapshots
3.2 | Added the `-p` option, and the ability to read SZX snapshots and 128K Z80 snapshots
2.1.2 | Added the ability to write the disassembly in lower case
2.1 | Added the `-H` option
2.0.1 | Added the `-o` option, and the ability to read binary files, to set the maximum number of characters in a DEFM statement, and to suppress comments that list routine entry point referrers
2.0 | Added the ability to set the maximum number of bytes in a DEFB statement
1.0.5 | Added the ability to show ASCII text in comment fields
1.0.4 | Added the `-s` option

## snapinfo.py

snapinfo.py shows information on the registers or RAM in a binary (raw memory) file or a SNA, SZX or Z80 snapshot. For example:

    $ snapinfo.py game.z80

To list the options supported by snapinfo.py, run it with no arguments:

    usage: snapinfo.py [options] file

    Analyse a binary (raw memory) file or a SNA, SZX or Z80 snapshot.

    Options:
      -b, --basic           List the BASIC program.
      -c PATH, --ctl PATH   When generating a call graph, specify a control file
                            to use, or a directory from which to read control
                            files. PATH may be '-' for standard input. This option
                            may be used multiple times.
      -f A[,B...[-M[-N]]], --find A[,B...[-M[-N]]]
                            Search for the byte sequence A,B... with distance
                            ranging from M to N (default=1) between bytes.
      -g, --call-graph      Generate a call graph in DOT format.
      -I p=v, --ini p=v     Set the value of the configuration parameter 'p' to
                            'v'. This option may be used multiple times.
      -o ADDR, --org ADDR   Specify the origin address of a binary (raw memory)
                            file (default: 65536 - length).
      -p A[-B[-C]], --peek A[-B[-C]]
                            Show the contents of addresses A TO B STEP C. This
                            option may be used multiple times.
      -P PAGE, --page PAGE  Specify the page (0-7) of a 128K snapshot to map to
                            49152-65535.
      --show-config         Show configuration parameter values.
      -t TEXT, --find-text TEXT
                            Search for a text string.
      -T X,Y[-M[-N]], --find-tile X,Y[-M[-N]]
                            Search for the graphic data of the tile at (X,Y) with
                            distance ranging from M to N (default=1) between
                            bytes.
      -v, --variables       List variables.
      -V, --version         Show SkoolKit version number and exit.
      -w A[-B[-C]], --word A[-B[-C]]
                            Show the words at addresses A TO B STEP C. This option
                            may be used multiple times.

With no options, snapinfo.py displays register values, the interrupt mode, the border colour, and various other attributes. By using one of the options shown above, it can list the BASIC program and variables (if present), show the contents of a range of addresses, search the RAM for a sequence of byte values or a text string, or generate a call graph.

By default, the `--find`, `--find-text` and `--find-tile` options search all RAM banks in a 128K snapshot; use the `--page` option to restrict the search to the address range 16384-65535 (0x4000-0xFFFF).

### Call graphs

snapinfo.py can generate a call graph in DOT format from a snapshot and a corresponding control file. For example, if game.ctl is present alongside game.z80, then:

    $ snapinfo.py -g game.z80 > game.dot

will produce a call graph in game.dot, with a node for each routine declared in game.ctl, and an edge between two nodes whenever the routine represented by the first node calls, jumps to, or continues into the routine represented by the second node.

To create a PNG image file named game.png from game.dot, the dot utility (included in Graphviz) may be used:

    $ dot -Tpng game.dot > game.png

A call graph may contain one or more ‘orphans’, an orphan being a node that is not at the head of any arrow, and thus represents a routine that is (as far as snapinfo.py can tell) not used by any other routines. To declare the callers of such a routine (in case it is not a true orphan), the @refs directive may be used.

To help identify orphan nodes and missing edges, each of the first three lines of the DOT file produced by snapinfo.py contains a list of IDs of the following types of node:

- unconnected nodes

- orphan nodes connected to other nodes

- non-orphan nodes whose first instruction is not used

The appearance of nodes and edges in a call graph image can be configured via the `EdgeAttributes`, `GraphAttributes`, `NodeAttributes` and `NodeLabel` configuration parameters (see below).

### Configuration

snapinfo.py will read configuration from a file named skoolkit.ini in the current working directory or in ~/.skoolkit, if present. The recognised configuration parameters are:

- `EdgeAttributes` - the default attributes for edges in a call graph (default: none)

- `GraphAttributes` - the default attributes for a call graph (default: none)

- `NodeAttributes` - the default attributes for nodes in a call graph (default: `shape=record`)

- `NodeId` - the format of the node IDs in a call graph (default: `{address}`)

- `NodeLabel` - the format of the node labels in a call graph (default: `"{address} {address:04X}\n{label}"`)

- `Peek` - the format of each line of the output produced by the `--peek` option (default: `{address:>5} {address:04X}: {value:>3} {value:02X} {value:08b} {char}`)

- `Word` - the format of each line of the output produced by the `--word` option (default: `{address:>5} {address:04X}: {value:>5} {value:04X}`)

`NodeId` and `NodeLabel` are standard Python format strings that recognise the replacement fields `address` and `label` (the address and label of the first instruction in the routine represented by the node).

Configuration parameters must appear in a `[snapinfo]` section. For example, to make snapinfo.py use open arrowheads and a cyan background colour in call graphs by default, add the following section to skoolkit.ini:

    [snapinfo]
    EdgeAttributes=arrowhead=open
    GraphAttributes=bgcolor=cyan

Configuration parameters may also be set on the command line by using the `--ini` option. Parameter values set this way will override any found in skoolkit.ini.

Version | Changes
--- | ---
10.0 | Shows MEMPTR register value in SZX snapshots
9.4 | Shows AY register values in 128K SZX and Z80 snapshots and the last value written to port $FE in SZX snapshots
9.3 | The `--find`, `--find-text` and `--find-tile` options search all RAM banks in a 128K snapshot by default
9.0 | Shows the current AY register in 128K SZX and Z80 snapshots
8.10 | Shows the value of the T-states counter and the issue 2 emulation flag in SZX and Z80 snapshots
8.4 | Added the `Peek` and `Word` configuration parameters
8.3 | Added support for reading control files from a directory (`--ctl DIR`)
8.2 | Configuration is read from skoolkit.ini if present; added the ability to read binary files; added the `--call-graph`, `--ctl`, `--ini`, `--org`, `--page` and `--show-config` options
6.2 | The `--find`, `--find-tile`, `--peek` and `--word` options accept hexadecimal integers prefixed by ‘0x’
6.0 | Added support to the `--find` option for distance ranges; added the `--find-tile` and `--word` options; the `--peek` option shows UDGs and BASIC tokens
5.4 | Added the `--variables` option; UDGs in a BASIC program are shown as special symbols (e.g. `{UDG-A}`)
5.3 | New

## snapmod.py

snapmod.py modifies the registers and RAM in an SZX or Z80 snapshot. For example:

    $ snapmod.py --poke 32768,0 game.z80 poked.z80

To list the options supported by snapmod.py, run it with no arguments:

    usage: snapmod.py [options] infile [outfile]

    Modify an SZX or Z80 snapshot.

    Options:
      -m [s:]src,size,[d:]dest, --move [s:]src,size,[d:]dest
                            Copy a block of bytes of the given size from src in
                            RAM bank s to dest in RAM bank d. This option may be
                            used multiple times.
      --patch [p:]a,file    Apply a binary patch file at address 'a' in RAM bank
                            'p'. This option may be used multiple times.
      -p [p:]a[-b[-c]],[^+]v, --poke [p:]a[-b[-c]],[^+]v
                            POKE N,v in RAM bank p for N in {a, a+c, a+2c..., b}.
                            Prefix 'v' with '^' to perform an XOR operation, or
                            '+' to perform an ADD operation. This option may be
                            used multiple times.
      -r name=value, --reg name=value
                            Set the value of a register. Do '--reg help' for more
                            information. This option may be used multiple times.
      -s name=value, --state name=value
                            Set a hardware state attribute. Do '--state help' for
                            more information. This option may be used multiple
                            times.
      -V, --version         Show SkoolKit version number and exit.

Version | Changes
--- | ---
10.0 | Added support for setting the MEMPTR register in SZX snapshots
9.5 | Added the `--patch` option
9.1 | Added support for modifying SZX snapshots and 128K snapshots; the `--move` and `--poke` options can modify specific RAM banks
8.10 | Added the `issue2` hardware state attribute
8.9 | Added the `tstates` hardware state attribute
6.2 | The `--move`, `--poke` and `--reg` options accept hexadecimal integers prefixed by ‘0x’
5.3 | New

## tap2sna.py

tap2sna.py converts one or two PZX, TAP or TZX files (which may be inside a zip archive) into an SZX or Z80 snapshot. For example:

    $ tap2sna.py game.tap game.z80

To list the options supported by tap2sna.py, run it with no arguments:

    usage:
      tap2sna.py [options] INPUT [INPUT] [OUTFILE]
      tap2sna.py @FILE [args]

    Convert one or two PZX, TAP or TZX files (which may be inside a zip archive)
    into an SZX or Z80 snapshot. INPUT may be the full URL to a remote zip archive
    or tape file, or the path to a local file. If two INPUTs are given, they must
    both be (local or remote) tape files. Arguments may be read from FILE instead
    of (or as well as) being given on the command line.

    Options:
      -c name=value, --sim-load-config name=value
                            Set the value of a simulated LOAD configuration
                            parameter. Do '-c help' for more information, or '-c
                            help-name' for help on a specific parameter. This
                            option may be used multiple times.
      -d DIR, --output-dir DIR
                            Write the snapshot file in this directory.
      -I p=v, --ini p=v     Set the value of the configuration parameter 'p' to
                            'v'. This option may be used multiple times.
      --press N:KEYS        Pause the tape at block number N and press KEYS before
                            resuming. KEYS must be a space-separated list of key
                            identifiers. This option may be used multiple times.
      -p STACK, --stack STACK
                            Set the stack pointer.
      --ram OPERATION       Perform a load operation or otherwise modify the
                            memory snapshot being built. Do '--ram help' for more
                            information. This option may be used multiple times.
      --reg name=value      Set the value of a register. Do '--reg help' for more
                            information. This option may be used multiple times.
      --screen              Display screen contents while running.
      --show-config         Show configuration parameter values.
      -s START, --start START
                            Set the start address to JP to.
      --state name=value    Set a hardware state attribute. Do '--state help' for
                            more information. This option may be used multiple
                            times.
      --tape-analysis       Show an analysis of the tape's tones, pulse sequences
                            and data blocks.
      --tape-name NAME      Specify the name of a tape file in a zip archive. Use
                            this option twice when loading two tape files.
      --tape-skip A[-B]     Skip block numbers A-B on the tape.
      --tape-start BLOCK    Start the tape at this block number.
      --tape-stop BLOCK     Stop the tape at this block number.
      --tape-sum MD5SUM     Specify the MD5 checksum of the tape file. This option
                            may be used twice if loading two tape files.
      -u AGENT, --user-agent AGENT
                            Set the User-Agent header.
      -V, --version         Show SkoolKit version number and exit.

Note that tap2sna.py cannot read data from TZX block types 0x18 (CSW recording) or 0x19 (generalized data block).

By default, tap2sna.py attempts to load a tape exactly as a 48K Spectrum would (see Simulated LOAD). If that doesn’t work, the `--ram` option can be used to load bytes from specific tape blocks at the appropriate addresses. For example:

    $ tap2sna.py --ram load=3,30000 game.tzx game.z80

loads the third block on the tape at address 30000, and ignores all other blocks. (To see information on the blocks in a tape file, use the tapinfo.py command.)

The `--ram` option can also be used to move blocks of bytes from one location to another, apply a binary patch file, POKE values into individual addresses or address ranges, modify memory with XOR and ADD operations, initialise the system variables, or call a Python function to modify the memory snapshot in an arbitrary way before it is saved. For more information on these operations, run:

    $ tap2sna.py --ram help

If a game requires loading from both sides of a tape, and each side is in its own file in a zip archive, they can be loaded by specifying their names in the desired order using the `--tape-name` option:

    $ tap2sna.py --tape-name side1.tzx --tape-name side2.tzx game.zip

If each side is in its own file and not in a zip archive, they can be loaded by specifying them as positional arguments in the desired order:

    $ tap2sna.py side1.tzx side2.tzx

When loading from two tape files, and using the `--tape-stop` option to stop somewhere in the middle of the second tape, the block number argument must be incremented by the number of blocks in the first tape. For example, if the first tape has five blocks, `--tape-stop 8` will stop at the third block of the second tape.

For complex snapshots that require many options to build, it may be more convenient to store the arguments to tap2sna.py in a file. For example, if the file game.t2s has the following contents:

    ;
    ; tap2sna.py file for GAME
    ;
    http://example.com/pub/games/GAME.zip
    -c fast-load=0       # Disable fast loading
    -c accelerator=none  # Disable tape-sampling loop acceleration
    --state issue2=1     # Enable issue 2 keyboard emulation
    --start 34816        # Start at 34816

then:

    $ tap2sna.py @game.t2s

will create game.z80 as if the arguments specified in game.t2s had been given on the command line. When tap2sna.py reads arguments from a file whose name ends with ‘.t2s’, the output snapshot filename defaults to the name of that arguments file with ‘.t2s’ replaced by either ‘.z80’ or ‘.szx’ (depending on the value of the `DefaultSnapshotFormat` configuration parameter).

### Simulated LOAD

By default, tap2sna.py simulates a freshly booted 48K ZX Spectrum running LOAD “” (or LOAD “”CODE, if the first block on the tape is a ‘Bytes’ header). Whenever the Spectrum ROM’s load routine at $0556 is called, a shortcut is taken by “fast loading” the next block on the tape. All other code (including any custom loader) is fully simulated. Simulation continues until the program counter hits the start address given by the `--start` option, or 15 minutes of simulated Z80 CPU time has elapsed, or the end of the tape is reached and one of the following conditions is satisfied:

- a custom loader was detected

- the program counter hits an address outside the ROM

- more than one second of simulated Z80 CPU time has elapsed since the end of the tape was reached

A simulated LOAD can also be aborted by pressing Ctrl-C. When a simulated LOAD has completed or been aborted, the values of the registers (including the program counter) in the simulator are used to populate the snapshot.

A simulated LOAD can be configured via parameters that are set by the `--sim-load-config` (or `-c`) option. The recognised configuration parameters are:

- `accelerate-dec-a` - enable acceleration of ‘DEC A: JR NZ,$-1’ delay loops only (`1`), or ‘DEC A: JP NZ,$-1’ delay loops only (`2`), or both (`3`, the default), or neither (`0`)

- `accelerator` - a comma-separated list of tape-sampling loop accelerators to use (see Accelerators)

- `cmio` - enable simulation of memory and I/O contention delays and the MEMPTR register (`1`), or disable it (`0`); this is disabled by default to improve performance, but some loaders may require it; when this is enabled, all acceleration is disabled

- `fast-load` - enable fast loading whenever the ROM loader is called (`1`, the default), or disable it (`0`); fast loading (also known as “flash loading”) significantly reduces the load time for many tapes, but can also cause some loaders to fail

- `finish-tape` - run the tape to the end before stopping the simulation at the address specified by the `--start` option (`1`), or stop the simulation as soon as that address is reached, regardless of whether the tape has finished (`0`, the default)

- `first-edge` - the time (in T-states) from the start of the tape at which to place the leading edge of the first pulse (default: `0`)

- `in-flags` - various flags specifying how to handle ‘IN’ instructions (see below)

- `load` - a space-separated list of keys to press to build an alternative command line to load the tape (see LOAD command)

- `machine` - the type of machine to simulate: a 48K Spectrum (`48`, the default), or a 128K Spectrum (`128`)

- `pause` - pause the tape between blocks and resume playback when port 254 is read (`1`, the default), or run the tape continuously (`0`); pausing can help with tapes that require (but do not actually contain) long pauses between blocks, but can cause some loaders to fail

- `polarity` - the EAR bit reading produced by the first pulse on the tape: `0` (the default) or `1`; subsequent pulses give readings that alternate between 0 and 1

- `python` - whether to use the pure Python Z80 simulator (`1`), or the much faster C version if available (`0`, the default)

- `timeout` - the number of seconds of Z80 CPU time after which to abort the simulated LOAD if it’s still in progress (default: 900)

- `trace` - the file to which to log all instructions executed during the simulated LOAD (default: none)

The `in-flags` parameter is the sum of the following values, chosen according to the desired behaviour:

- 1 - interpret ‘IN A,($FE)’ instructions in the address range $4000-$7FFF as reading the tape (by default they are ignored)

- 2 - ignore ‘IN’ instructions in the address range $4000-$FFFF (i.e. in RAM) that read port $FE

- 4 - yield a simulated port reading when executing an ‘IN r,(C)’ instruction (by default such an instruction always yields the value $FF)

By default, the EAR bit reading produced by a pulse is 0 if the 0-based index of the pulse is even (i.e. first, third, fifth pulses etc.), or 1 otherwise. This can be reversed by setting `polarity=1`. Run tap2sna.py with the `--tape-analysis` option to see the timings and EAR bit readings of the pulses on a tape.

If the `--screen` option is given and pygame is installed, tap2sna.py will use it to render the Spectrum’s screen contents at 50 frames per second with a scale factor of 2 while the simulated LOAD is running. The frame rate and scale factor can be changed by setting the `ScreenFps` and `ScreenScale` configuration parameters.

### Accelerators

The `accelerator` simulated LOAD configuration parameter must be either a comma-separated list of specific accelerator names or one of the following special values:

- `auto` - select accelerators automatically (this is the default)

- `list` - list the accelerators used during a simulated LOAD, along with the hit/miss counts generated by the tape-sampling loop detector

- `none` - disable acceleration; the loading time for a game with a custom loader that uses an unrecognised tape-sampling loop may be reduced by specifying this value

A tape-sampling loop accelerator works by effectively fast-forwarding the tape (and the state of the loop itself) to the next edge whenever the loop is entered. This technique is known as “edge loading”.

The output produced by `accelerator=list` looks something like this:

    Accelerators: microsphere: 5500; rom: 793036; misses: 0; dec-a: 800708/0/23

This means that:

- the `microsphere` and `rom` tape-sampling loops were detected, 5500 times and 793036 times respectively

- no instances of an ‘IN A,($FE)’ instruction outside a recognised tape-sampling loop were executed (0 misses)

- 800708 ‘DEC A: JR NZ,$-1’ delay loops were entered, no ‘DEC A: JP NZ,$-1’ delay loops were entered, and 23 instances of ‘DEC A’ outside such delay loops were executed

To show the names of the available tape-sampling loop accelerators:

    $ tap2sna.py -c help-accelerator

### LOAD command

The `load` simulated LOAD configuration parameter may be used to specify an alternative command line to load the tape in cases where neither ‘LOAD “”’ nor ‘LOAD “”CODE’ works. Its value is a space-separated list of ‘words’ (a ‘word’ being a sequence of any characters other than space), each of which is broken down into a sequence of one or more keypresses. If a word contains the ‘+’ symbol, the tokens it separates are converted into keypresses made simultaneously. If a word matches a BASIC token, the corresponding sequence of keypresses to produce that token are substituted. Otherwise, each character in the word is converted individually into the appropriate keypresses.

The following special tokens are also recognised:

- `CS` - CAPS SHIFT

- `SS` - SYMBOL SHIFT

- `SPACE` - SPACE

- `ENTER` - ENTER

- `DOWN` - Cursor down (‘CS+6’)

- `GOTO` - GO TO (‘g’)

- `GOSUB` - GO SUB (‘h’)

- `DEFFN` - DEF FN (‘CS+SS SS+1’)

- `OPEN#` - OPEN # (‘CS+SS SS+4’)

- `CLOSE#` - CLOSE # (‘CS+SS SS+5’)

- `PC=address` - Stop the keyboard input simulation at this address

The `PC=address` token, if present, must appear last. The default address is either 0x0605 (when a 48K Spectrum is being simulated) or 0x13BE (on a 128K Spectrum). The simulated LOAD begins at this address.

`ENTER` is automatically appended to the command line if not already present.

For example, the `load` parameter may be set to:

    CLEAR 34999: LOAD "" CODE : RANDOMIZE USR 35000

Note that the spaces around `CLEAR`, `LOAD`, `CODE`, `RANDOMIZE` and `USR` are required in order for them to be recognised as BASIC tokens.

### User input

Some tapes require the user to pause the tape before loading has finished, press one or more keys, and then start the tape again to resume loading. Such tapes can be handled by using the `--press` option. Its single argument takes the form:

    N:KEYS

where:

- `N` is the block number at which to pause the tape

- `KEYS` is a space-separated list of key identifiers

For example:

    $ tap2sna.py --press 5:ENTER game.tzx

This will load blocks 1-4 of game.tzx, pause the tape, simulate pressing the ENTER key until the appropriate key row has been read, and then start the tape (whereupon block 5 and any other remaining blocks will be loaded).

The `KEYS` list recognises the digits 0-9 and lower case letters a-z as valid key identifiers, along with the following special tokens:

- `CS` - CAPS SHIFT

- `SS` - SYMBOL SHIFT

- `SPACE` - SPACE

- `ENTER` - ENTER

- `NONE` - no key

Sometimes a single keypress may need to be read more than once before the game’s loader responds to it. In such cases the `*` notation is useful:

    $ tap2sna.py --press 6:s*3 game.tzx

Equivalent to `6:s s s`, this will wait until the ‘s’ keypress has been read three times before resuming the tape at block number 6.

### Configuration

tap2sna.py will read configuration from a file named skoolkit.ini in the current working directory or in ~/.skoolkit, if present. The recognised configuration parameters are:

- `DefaultSnapshotFormat` - the format of the snapshot written when no output snapshot argument is specified; valid values are `z80` (the default) and `szx`

- `ScreenFps` - screen refresh rate in frames per second (default: `50`); if set to 0, tap2sna.py runs at maximum speed

- `ScreenScale` - screen scale factor (default: `2`)

- `TraceLine` - the format of each line in the trace log file for a simulated LOAD (default: `${pc:04X} {i}`)

- `TraceOperand` - the prefix, byte format, and word format for the numeric operands of instructions in the trace log file for a simulated LOAD, separated by commas (default: `$,02X,04X`); the byte and word formats are standard Python format specifiers for numeric values, and default to empty strings if not supplied

- `UserAgent` - the value of the User-Agent header in HTTP/HTTPS requests (default: empty string)

`TraceLine` is a standard Python format string that recognises the following replacement fields:

- `i` - the current instruction

- `m[address]` - the contents of a memory address

- `pc` - the address of the current instruction (program counter)

- `r[X]` - the ‘X’ register (see below)

- `t` - the current timestamp

When using the `m` (memory) replacement field, `address` must be either a decimal number, or a hexadecimal number prefixed by ‘$’ or ‘0x’.

The register name `X` in `r[X]` must be one of the following:

    a b c d e f h l bc de hl
    ^a ^b ^c ^d ^e ^f ^h ^l ^bc ^de ^hl
    ix ixh ixl iy iyh iyl
    i r sp memptr

The names that begin with `^` denote the shadow registers.

The current timestamp (`t`) is the number of T-states that have elapsed since the start of the simulation, according to the simulator’s internal clock. In order to maintain synchronisation with the tape being loaded, the simulator’s clock is adjusted to match the timestamp of the first pulse in each block (as shown by the `--tape-analysis` option) when that block is reached. (The simulator’s clock may at times become desynchronised with the tape because, by default, the tape is paused between blocks, and resumed when port 254 is read.)

Configuration parameters must appear in a `[tap2sna]` section. For example, to make tap2sna.py write instruction addresses and operands in a trace log file in decimal format by default, add the following section to skoolkit.ini:

    [tap2sna]
    TraceLine={pc:05} {i}
    TraceOperand=

Configuration parameters may also be set on the command line by using the `--ini` option. Parameter values set this way will override any found in skoolkit.ini.

Version | Changes
--- | ---
10.1 | Added the `--screen` option; added the `ScreenFps` and `ScreenScale` configuration parameters
10.0 | Added support for setting the MEMPTR register in SZX snapshots; added support for the `r[memptr]` replacement field in the `TraceLine` configuration parameter
9.6 | Added the ability to load from two tape files; added the `--press` and `--tape-skip` options; added support to the `--ram` option for the `patch` operation; changed the default value of the `accelerate-dec-a` simulated LOAD configuration parameter from `1` to `3`; added the `activision`, `alternative3`, `audiogenic-0`, `audiogenic-1`, `codemasters`, `diver`, `gremlin2-0`, `gremlin2-1`, `kwc-0`, `kwc-1`, `mirrorsoft2` and `operasoft` tape-sampling loop accelerators; removed the `dinaload`, `gremlin2`, `housenka`, `suzy-soft` and `suzy-soft2` tape-sampling loop accelerators
9.5 | Added the `UserAgent` configuration parameter
9.3 | Added support for PZX files; added support for the `m` (memory) replacement field in the `TraceLine` configuration parameter
9.2 | Added support for TZX block type 0x15 (direct recording); added the `python` simulated LOAD configuration parameter
9.1 | The `--ram move` and `--ram poke` options can modify specific RAM banks; added the `cmio` simulated LOAD configuration parameter
9.0 | A simulated LOAD is performed by default; an existing snapshot will be overwritten by default; added the `load`, `machine`, `polarity` and `in-flags` simulated LOAD configuration parameters; the output snapshot argument is optional; added support for writing SZX snapshots; added the `DefaultSnapshotFormat` configuration parameter; added the `fe` hardware state attribute; added support for register pairs (`r[bc]`, `r[de]` etc.) in the `TraceLine` configuration parameter; added the `antirom`, `ernieware` and `housenka` tape-sampling loop accelerators; shows ‘DEC A’ delay loop statistics when `accelerator=list`
8.10 | Configuration is read from skoolkit.ini if present; added the `--ini`, `--show-config` and `--tape-analysis` options; added the `TraceLine` and `TraceOperand` configuration parameters; added the `accelerate-dec-a` and `finish-tape` simulated LOAD configuration parameters; added the `issue2` hardware state attribute; added the special `auto` and `list` tape-sampling loop accelerator names, and the ability to specify multiple accelerators; added the `alkatraz-05`, `alkatraz-09`, `alkatraz-0a`, `alkatraz-0b`, `alternative`, `alternative2`, `boguslaw-juza`, `bulldog`, `crl`, `crl2`, `crl3`, `crl4`, `cybexlab`, `d-and-h`, `delphine`, `design-design`, `gargoyle2`, `gremlin2`, `microprose`, `micro-style`, `mirrorsoft`, `palas`, `raxoft`, `realtime`, `silverbird`, `software-projects`, `sparklers`, `suzy-soft`, `suzy-soft2`, `tiny`, `us-gold` and `weird-science` tape-sampling loop accelerators
8.9 | Added the `--sim-load-config`, `--tape-name`, `--tape-start`, `--tape-stop` and `--tape-sum` options; added support for TZX loops, pauses, and unused bits in data blocks; added support for quoted arguments in an arguments file; added the `tstates` hardware state attribute
8.8 | A simulated LOAD performs any `call/move/poke/sysvars` operations specified by `--ram`
8.7 | Added support for simulating a 48K Spectrum LOADing a tape; when a headerless block is ignored because no `--ram load` options have been specified, a warning is printed
8.6 | Added support to the `--ram` option for the `call` operation
8.4 | Added support to the `--ram` option for the `sysvars` operation
6.3 | Added the `--user-agent` option
6.2 | The `--ram`, `--reg`, `--stack` and `--start` options accept hexadecimal integers prefixed by ‘0x’
5.3 | Added the `--stack` and `--start` options
4.5 | Added support for TZX block type 0x14 (pure data), for loading the first and last bytes of a tape block, and for modifying memory with XOR and ADD operations
3.5 | New

## tapinfo.py

tapinfo.py shows information on the blocks in a PZX, TAP or TZX file. For example:

    $ tapinfo.py game.tzx

To list the options supported by tapinfo.py, run it with no arguments:

    usage: tapinfo.py [options] FILE

    Show the blocks in a PZX, TAP or TZX file.

    Options:
      -b N[,A], --basic N[,A]
                            List the BASIC program in block N loaded at address A
                            (default 23755).
      -d, --data            Show the entire contents of header and data blocks.
      --tape-start BLOCK    Start at this tape block number.
      --tape-stop BLOCK     Stop at this tape block number.
      -V, --version         Show SkoolKit version number and exit.

Version | Changes
--- | ---
9.3 | Added support for PZX files; added the `--tape-start` and `--tape-stop` options; shows info for TZX block types 0x18 (CSW recording) and 0x2B (set signal level); recognises deprecated TZX block types 0x16, 0x17, 0x34 and 0x40
9.2 | Shows info for TZX block type 0x15 (direct recording)
9.0 | Shows the LINE number (if present) for ‘Program:’ header blocks; renders BASIC tokens in header block names
8.9 | Shows full info for TZX block types 0x10 and 0x11
8.3 | Added the `--data` option
8.1 | Shows contents of TZX block types 0x33 (hardware type) and 0x35 (custom info)
7.1 | Shows pulse lengths in TZX block type 0x13 and full info for TZX block type 0x14
6.2 | The `--basic` option accepts a hexadecimal address prefixed by ‘0x’
6.0 | Added the `--basic` option
5.0 | New

## trace.py

trace.py simulates the execution of machine code in a 48K, 128K or +2 memory snapshot. For example:

    $ trace.py --start 32768 --stop 49152 game.z80

To list the options supported by trace.py, run it with no arguments:

    usage: trace.py [options] FILE [OUTFILE...]

    Trace Z80 machine code execution. FILE may be a binary (raw memory) file, a
    SNA, SZX or Z80 snapshot, or '48', '128' or '+2' for no snapshot. If 'OUTFILE'
    is given, an SZX/Z80 snapshot, WAV file or PNG file is written after execution
    has completed.

    Options:
      --audio               Show beeper delays.
      --ay                  Capture AY audio (when writing a WAV file).
      --ay-mode MODE        Set AY mode to ABC, ACB or MONO (the default).
      --ay-res T            Set AY sampling resolution to this many T-states
                            (default: 622).
      --beeper              Capture beeper audio (when used with --ay).
      -c, --cmio            Simulate memory and I/O contention and the MEMPTR
                            register.
      -D, --decimal         Show decimal values in verbose mode.
      --depth DEPTH         Simplify audio delays to this depth (default: 2).
      -I p=v, --ini p=v     Set the value of the configuration parameter 'p' to
                            'v'. This option may be used multiple times.
      --map FILE            Log addresses of executed instructions to a file.
      -m MAX, --max-operations MAX
                            Maximum number of instructions to execute.
      -M MAX, --max-tstates MAX
                            Maximum number of T-states to run for.
      -n, --no-interrupts   Don't execute interrupt routines.
      -o ADDR, --org ADDR   Specify the origin address of a binary (raw memory)
                            file (default: 65536 - length).
      -p [p:]a[-b[-c]],[^+]v, --poke [p:]a[-b[-c]],[^+]v
                            POKE N,v in RAM bank p for N in {a, a+c, a+2c..., b}
                            before execution begins. Prefix 'v' with '^' to
                            perform an XOR operation, or '+' to perform an ADD
                            operation. This option may be used multiple times.
      --python              Use the pure Python Z80 simulator.
      -r name=value, --reg name=value
                            Set the value of a register before execution begins.
                            Do '--reg help' for more information. This option may
                            be used multiple times.
      --rom FILE            Patch in a ROM at address 0 from this file.
      --show-config         Show configuration parameter values.
      -s ADDR, --start ADDR
                            Start execution at this address.
      -S ADDR, --stop ADDR  Stop execution at this address.
      --screen              Display screen contents and respond to keypresses
                            while running.
      --state name=value    Set a hardware state attribute before execution
                            begins. Do '--state help' for more information. This
                            option may be used multiple times.
      --stats               Show stats after execution.
      -v, --verbose         Show executed instructions. Repeat this option to show
                            register values too.
      -V, --version         Show SkoolKit version number and exit.
      --volume VOL          Set audio volume percentage (default: 100).

By default, trace.py silently simulates code execution beginning with the instruction at the address specified by the `--start` option (or the program counter in the snapshot) and ending when the instruction at the address specified by `--stop` (if any) is reached. Use the `--verbose` option to show each instruction executed. Repeat the `--verbose` option (`-vv`) to show register values too.

When the `--audio` option is given, trace.py tracks changes in the state of the ZX Spectrum speaker, and then prints a list of the delays (in T-states) between those changes. This list can be supplied to the #AUDIO macro to produce a WAV file for the sound effect that would be produced by the same code running on a real ZX Spectrum.

When writing a WAV file, trace.py captures only beeper activity by default. To capture AY activity instead, use the `--ay` option. To capture both AY and beeper activity, use the `--ay` and `--beeper` options together. By default, the AY registers are sampled at a resolution of 622 T-states (5700Hz), which is usually good enough for capturing AY speech. The sampling resolution can be changed by using the `--ay-res` option. A higher value such as 70908 (50Hz) is usually good enough for capturing AY music, and may also require less time to produce the WAV file.

If the `--screen` option is given and pygame is installed, trace.py will use it to render the Spectrum’s screen contents at 50 frames per second with a scale factor of 2 while running. The frame rate and scale factor can be changed by setting the `ScreenFps` and `ScreenScale` configuration parameters. While the screen is displayed, trace.py will also respond to keypresses, with the left shift key mapped to CAPS SHIFT on the Spectrum keyboard, and the left Ctrl key mapped to SYMBOL SHIFT.

### Configuration

trace.py will read configuration from a file named skoolkit.ini in the current working directory or in ~/.skoolkit, if present. The recognised configuration parameters are:

- `PNGScale` - the PNG image scale factor (default: `2`)

- `Screen` - display screen contents while running (`1`), or don’t (`0`, the default)

- `ScreenFps` - screen refresh rate in frames per second (default: `50`); if set to 0, trace.py runs at maximum speed

- `ScreenScale` - screen scale factor (default: `2`)

- `TraceHeader` - the header to print when `-v` is used (default: None)

- `TraceHeader2` - the header to print when `-vv` is used (default: None)

- `TraceLine` - the format of each instruction line when `-v` is used (default: `${pc:04X} {i}`)

- `TraceLine2` - the format of each instruction line when `-vv` is used (use `--show-config` to see the default value)

- `TraceLineDecimal` - the format of each instruction line when `-Dv` is used (default: `{pc:05} {i}`)

- `TraceLineDecimal2` - the format of each instruction line when `-Dvv` is used (use `--show-config` to see the default value)

- `TraceOperand` - the prefix, byte format, and word format for the numeric operands of instructions, separated by commas (default: `$,02X,04X`); the byte and word formats are standard Python format specifiers for numeric values, and default to empty strings if not supplied

- `TraceOperandDecimal` - as `TraceOperand` when `-D` is used (default: `,,`)

The `TraceLine*` parameters are standard Python format strings that recognise the following replacement fields:

- `i` - the current instruction

- `m[address]` - the contents of a memory address

- `pc` - the address of the current instruction (program counter)

- `r[X]` - the ‘X’ register (see below)

- `t` - the current timestamp (in T-states)

When using the `m` (memory) replacement field, `address` must be either a decimal number, or a hexadecimal number prefixed by ‘$’ or ‘0x’.

The register name `X` in `r[X]` must be one of the following:

    a b c d e f h l bc de hl
    ^a ^b ^c ^d ^e ^f ^h ^l ^bc ^de ^hl
    ix ixh ixl iy iyh iyl
    i r sp memptr

The names that begin with `^` denote the shadow registers.

Wherever `\n` appears in a `TraceHeader*` or `TraceLine*` parameter value, it is replaced by a newline character.

Configuration parameters must appear in a `[trace]` section. For example, to make trace.py write a timestamp for each instruction when `-v` is used, add the following section to skoolkit.ini:

    [trace]
    TraceLine={t:>10} ${pc:04X} {i}

Configuration parameters may also be set on the command line by using the `--ini` option. Parameter values set this way will override any found in skoolkit.ini.

Version | Changes
--- | ---
10.1 | Added the `--ay-mode`, `--ay-res` and `--volume` options; added support for multiple colours in the border area of the screen
10.0 | Added the `--ay` and `--beeper` options and support for capturing AY audio; added support to the `--reg` option for setting the MEMPTR register; reads and writes the MEMPTR register in SZX snapshots; added support for the `r[memptr]` replacement field in the `TraceLine*` configuration parameters; added the `TraceHeader` and `TraceHeader2` configuration parameters; added a border area to the screen
9.6 | Added the `Screen` configuration parameter
9.5 | Responds to keypresses while the screen is displayed; added the `--map` option
9.4 | Added the `--screen` option; added support for writing a PNG file after execution has completed; added the `PNGScale`, `ScreenFps` and `ScreenScale` configuration parameters; added support for multiple output file arguments
9.3 | Added the `--state` option; added support for writing a WAV file after execution has completed; added support for the `m` (memory) replacement field in the `TraceLine*` configuration parameters
9.2 | Added the `--python` option; added support for +2 snapshots
9.1 | The `--poke` option can modify specific RAM banks; added the `--cmio` option
9.0 | Configuration is read from skoolkit.ini if present; added the `--ini`, `--no-interrupts` and `--show-config` options; interrupt routines are executed by default; added support for 128K snapshots; added support for writing SZX snapshots; added the `-m` and `-M` short options
8.9 | Reads and writes the T-states counter in Z80 snapshots and reads the T-states counter in SZX snapshots
8.8 | New