Spectrum game disassembly toolkit

SkoolKit is a collection of utilities that can be used to disassemble a Spectrum game (or indeed any piece of Spectrum software written in machine code) into a format known as a skool file. Then, from this skool file, you can use SkoolKit to create a browsable disassembly in HTML format, or a re-assemblable disassembly in ASM format. So the skool file is - from start to finish as you develop it by organising and annotating the code - the common ‘source’ for both the reader-friendly HTML version of the disassembly, and the developer- and assembler-friendly ASM version of the disassembly.

Download SkoolKit

The latest version of SkoolKit is 7.2. It was released on 2019-06-02.

Older versions

To use SkoolKit, you will need Python version 3.4+. Windows users should get Python here.


SkoolKit can:

  • convert a TAP or TZX file into a ‘pristine’ snapshot (using
  • disassemble SNA, Z80 and SZX snapshots as well as raw memory files
  • distinguish code from data by using a code execution map produced by an emulator
  • build still and animated PNG/GIF images from graphic data in the game snapshot (using the #UDG, #UDGARRAY, #FONT and #SCR macros)
  • create hyperlinks between routines and data blocks that refer to each other (by use of the #R macro in annotations, and automatically in the operands of CALL and JP instructions)
  • neatly render lists of bugs, trivia and POKEs on separate pages (using [Bug::], [Fact::] and [Poke::] sections in a ref file)
  • produce ASM files that include bugfixes declared in the skool file (with @ofix, @bfix and other ASM directives)
  • produce TAP files from assembled code (using

For a demonstration of SkoolKit’s capabilities, take a look at the complete disassemblies of Skool Daze, Back to Skool, Contact Sam Cruise, Manic Miner, Jet Set Willy and Hungry Horace.

Quick start guide

SkoolKit includes fairly detailed documentation, but if you want to get up and running quickly, here goes.

To convert a SNA, Z80 or SZX snapshot of a Spectrum game into a skool file (so that it can be converted into an HTML or ASM disassembly), copy the snapshot to the SkoolKit directory and run:

$ ./ game.z80 > game.skool

To split the disassembly up into code and data blocks, you’ll need a control file.

To turn this skool file into an HTML disassembly:

$ ./ game.skool

To turn it into an ASM file that can be fed to an assembler:

$ ./ game.skool > game.asm