Getting started

The repository ships the listing already generated, but what really matters is that it can be rebuilt from the cartridge and that the result is the ROM byte for byte. That is what makes the notes worth believing.

What you need

• Python 3 (that is all: not one dependency)
• pasmo, the Z80 assembler, for the reassembly check
• make
• For the checks against the real machine, openMSX

The cartridge

It does not travel with the repository. Put it in the root as hypersports3.rom, exactly 32,768 bytes:

247a14766d3c64c88707ee0bfd1a0255182acab98006d2c2646085e00db29936

To check it is the same one:

make comprueba

Rebuilding everything

make

That chains the four things that matter:

1. make listado traces the flow from the declared entry points and writes src/hypersports3.asm.
2. make verify reassembles it with pasmo and compares the binary against the ROM. If it is not 32,768 identical bytes, it fails.
3. make sanity checks what reassembly cannot see: that no byte declared as data is being read as code, that no entry point falls inside a data region, and that not one byte is left unassigned.
4. make test runs the 33 tests over the listing and the site.

The numbers

make densidad

Gives the two used across the series: how many routines are below 10 % of commented instructions, and the overall density. Here they are 0 out of 931 and 34.5 %.

The pictures

make imagenes

Draws the screens from the bytes of the ROM, running in Python the same decompressor, the same figure engine and the same label interpreter the Z80 runs. There is not one screen capture in this repository.

And to check those drawings are the real thing:

make vram

runs the cartridge in openMSX, dumps the 16 KB of VRAM at several instants, and tools/coteja_vram.py compares them byte for byte against what Python builds. Looking at the picture is not enough; that already cost four errors that had passed the eye test.