prosolis
22c67f1cb8
Eleven watcher shells and one MAME instance were left running for over an hour. Both had the same shape: a wait that can never be satisfied. - `until ! pgrep -f foo.py` matches the watching shell's own command line, so the loop never terminates. Wait on a PID or a sentinel file instead. - `timeout N mame` sends a SIGTERM that MAME ignores when its autoboot script is blocked; without `-k` the process spins at 100% CPU forever. Also gitignore vasm's default `a.out` output. Claude-Session: https://claude.ai/code/session_01194oWYW8DQXK1SZ2DnChW6
Dragon's Lair — Sharp X68000 port
Porting Dragon's Lair to a stock X68000 (68000 @ 10MHz, 2MB, SASI/SCSI).
This is fundamentally a video codec problem, not a game-logic problem: the game logic is a scene table with branching input windows; the difficulty is pushing ~22 minutes of Don Bluth animation through a 10MHz 68000.
Read first
docs/FINDINGS.md— measured hardware facts, content statistics, codec decision, and a section on measurement traps that produced three separate false results. Read §4 before trusting any pipeline number.docs/STATUS.md— current state, working setup, blockers, next steps. Start here. It also lists what has been explicitly abandoned, so old ideas do not get re-proposed.docs/BENCHMARK.md— how to measure the storage subsystem, and why a bandwidth figure out of MAME would be meaningless.docs/HARDWARE.md— X68000 GVRAM/CRTC reference.
Layout
docs/ findings, status, hardware reference
tools/analysis/ measurement scripts, numbered in the order they were written
(01/02 marked BROKEN deliberately, kept as regression refs).
Run from the repo root — they import from tools/encoder/.
tools/bench/ MAME Lua injection harness + 68000 benchmark sources
tools/vasm/ vasm m68k assembler (built from source)
tools/encoder/ hybrid VQ encoder + DLX1 container writer (working)
src/player/ 68000 player (not yet written)
assets/ extracted frames/audio (gitignored)
Encoder
python3 tools/encoder/extract.py 00020 /tmp/fr 12 crop
python3 tools/encoder/encode.py /tmp/fr out.dlx --profile sasi --preview p.png
Two quality profiles ship from one codec and one decoder — sasi (110 KB/s) and
scsi (280 KB/s) are two points on the same rate-distortion curve. The codec is
a Cinepak-style hybrid: each 4x4 block is coded as SKIP, one 4x4 codeword, four
2x2 codewords, or RAW literal pixels, chosen per block by rate-distortion.
The RAW escape means lam=0 is pixel-exact against the palettised frame, so the
quality knob spans lossless to heavily-compressed without changing the bitstream.
Profiles are derived from a bandwidth figure, not chosen by eye:
python3 tools/encoder/profile_gen.py --bw-mbps 4 --name scsi
On reading
docs/FINDINGS.md: it is append-only and several later sections overturn earlier ones. Superseded sections carry a blockquote at the top pointing to the correction — heed those, especially 18 (reversed by 21).
Source media (DRAGONS_LAIR.iso) and ROMs are gitignored — supply your own.