Unlock the speed

By | July 4, 2015

BUG OFF YOU BIG WALLYSkoolKit 4.5 has been released. Fresh copies are available for collection, as usual, from the download page, the Python Package Index, and the Ubuntu PPA.

But enough inane banter. What of the new features? Well, tap2sna.py has seen its first update since it was introduced in SkoolKit 3.5. Back then it could only read TZX block types 0x10 (standard speed data) and 0x11 (turbo speed data), but this set has been expanded by one (that’s 50%) to include block type 0x14 (pure data). In addition, tap2sna.py can now load the first and last bytes of a tape block (which are usually, but not always, the flag and parity bytes), and also modify memory with XOR and ADD operations. In case you’re struggling to see the point of all this, one word: Speedlock. Speedlock TZX files typically have the bulk of their data encoded in pure data blocks that have no flag or parity bytes and are scrambled by XOR and ADD operations. If the point is still not clear, come back to it later and try again with fresh eyes.

Elsewhere in the arena of SkoolKit commands, bin2tap.py has picked up a couple of new abilities. First, the --clear option, which creates a BASIC loader that has a CLEAR command, and otherwise leaves the stack pointer alone. This option enables you create a TAP file for a program that will run and then return to BASIC without crashing. Second, bin2tap.py can now convert not only a raw memory file, but also a SNA, SZX or Z80 snapshot into a TAP file. Just use the --org option to specify the origin address, and the new --end option to specify the end address of the section of memory to dump onto the tape.

Speaking of origins and ends, skool2asm.py, skool2ctl.py and skool2sft.py now sport --start and --end options for specifying how much of the input skool file to convert to ASM, CTL or SFT format. And the --start and --end options of sna2skool.py now also take effect when used in conjunction with the --ctl or --sft option to read a control file or skool file template. In short, we all now have the power to tell SkoolKit where to start and where to stop, and it will obey.

Which brings us to the end of this brief review of 4.5. As always, a more detailed list of changes can be found in the changelog. After that, if you’re convinced that 4.5 is worth the upgrade, go get a copy and descramble yourself some Speedlock tapes.

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