This repository holds the commented disassembly of King's Valley (Konami, 1985), the 16 KB RC-727 cartridge for the MSX1.
The ROM is not distributed here. You need to put it in the root of the repository as kingsvalley.rom. To check it is the same one:
shasum -a 256 kingsvalley.rom
a8f807a0be90db6a01c43a948215a8761d1d7b92358279d6f2ce2dcfefab5d73make doesmake listado builds src/kingsvalley.asm from the trace and the notes
make verify reassembles the listing and compares it to the ROM, byte for byte
make sanity the four checks reassembling does NOT cover
make densidad counts how much of the listing is commented
make imagenes draws the declared graphic blocks, so you can look at them
make web builds the bilingual site in docs/Plain make runs listado, verify, sanity and test.
verify is the test that mattersA disassembly can be written many ways, and almost all of them are wrong in some way that does not show. The one test that admits no argument is to reassemble the listing and check that exactly the same ROM comes back: the 16,384 bytes, in the same order, with the same sha256.
That is what make verify does, and it has been run after every batch of work. If it ever fails, the listing is wrong, however nicely it reads.
Identical bytes say nothing about whether we have understood them. A data block read as if it were code produces the same binary and a lie in the listing. So make sanity runs four separate checks:
check_trace.py: nothing declared as data in the .nocode may have come out traced as code.check_datos_como_codigo.py: cross-checks the 110 declared data regions against the real trace.check_entradas.py: no entry point may land inside a data region.presupuesto.py: not one byte of the cartridge left unassigned. This is the demanding one, and today it passes: 0 bytes unexplained.Only three, all in src/:
kingsvalley.entries — the entry points static tracing cannot work out on its own: the header's INIT, the interrupt hook, the eleven destinations of the task table, and the loop closers the cartridge pushes onto the stack. Each with its justification written beside it.kingsvalley.nocode — the regions the tracer must not keep reading as code, with the reason for each.kingsvalley.notes — the L directives (a routine's name and description), C (a comment on one line) and D/F (a data block, its name and the width of its structure). It is the big file, and where everything understood actually lives.src/kingsvalley.asm is generated: never edited by hand.
Not one picture on the site is an emulator capture. They are all drawn by tools/pantallas.py from the bytes of the ROM, by running in Python the two script interpreters the Z80 runs. See The code for how they work.