pds6502

PDS 1.26 assembler for the Super Robin Hood and Magician sources. Both games assemble with this module. Each game keeps its own build script, because the cartridges are different machines: Super Robin Hood is mapper 71 with 16 KiB banks, and Magician is MMC3 with 8 KiB slots.

Clone this repository next to the game:

games/pds6502
games/SuperRobinHoodNESSource
games/magician-nes

Each game's asm/pds6502.py is a short loader. It imports pds6502.py from the sibling checkout. PDS6502_HOME overrides that path when the checkout lives somewhere else.

python3 asm/build_srh.py     # Super Robin Hood
python3 asm/build.py         # Magician

Assembler option 0

<expr and >expr each return one byte of a 16-bit value. Which arrow is the low byte is assembler option 0, the editor's "Swap < and >" switch (editor manual, section 9.2.3):

option 0,n	>$1234	<$1234
0	$12	$34
1	$34	$12

1 is the 6502 manual default: the arrow points at the byte. PDS loaded SETUP.PDS from the project directory before assembling (editor manual, section 9.2.8). examples/SETUP.PDS is that file for a project whose source never sets the switch. It selects 1, which is what the Super Robin Hood cartridge was built with.

Magician does not use that file. X0.PDS begins with option 0,0, and the assembler honors the directive.

radix 10 is the default. send is ignored. The listing switches in the assembler menu do not change the bytes.

Documentation

The docs/ directory holds markdown transcriptions of the PDS manuals:

• The_PDS_6502_Manual.md — the assembler language this module implements
• The_PDS_Editor_Manual.md — the editor, including assembler option 0 and SETUP.PDS
• P.D.S._Manual.md, PDS_guide_early_version.md, The_PDS_Z80_Manual.md — the rest of the set

What a game build owns

This module writes a flat PRG image and, on the last pass of run_all, records the bytes each bank directive downloaded. Placing those bytes into an iNES ROM is the game's build. Super Robin Hood files mapper 71 banks. Magician searches MMC3 slots and reads the flat image. Pointing one game's build at the other source will put the bytes in the wrong places.

Releases

Tagged releases (v*) publish a source archive of the assembler via GitHub Actions. Push a tag, or run the Release workflow from the Actions tab:

git tag v1.0.1
git push origin v1.0.1

Game builds that clone this repository (or set PDS6502_HOME) do not need the release artifacts; the tag is for pinned downloads and changelog tracking.