Goregirl

goregirlsdungeon.bsky.social

18 October 2026 20:13

Faster, Pussycat! Kill! Kill! (1965, Russ Meyer)

Negative Charge

negativecharge.bsky.social

17 October 2026 17:32

Here's a second Atari ST YM2149F tune converted to the BBC Micro SN76489. This one uses both hardware envelopes and timer effects across all three MFP timers that have to reproduced in software / 6522 IRQs on the BBC. There are a few glitches due to CPU demand, but working on reducing that. 🔊

Negative Charge

negativecharge.bsky.social

16 October 2026 12:18

Thanks Matt. It's a great tune. Getting the timing effects to work at all on the BBC Micro's 6522 VIAs has been a long and painful journey (many stalled attempts) so glad it's working now. I may regret it, but I'm going to try !Cube's Bullet Sequence next which I believe uses all 3 MFP timers.

Negative Charge

negativecharge.bsky.social

16 October 2026 10:25

Things the BBC Micro SN76489 shouldn't be able to do - Part 2 So it's possible to create a basic software emulation of the SID chip. Now, what should be an easier task of emulating the YM2149F, as we're dealing with square waves and hardware envelopes, but also MPF timer effects - it wasn't. 🔊

matt sephton

gingerbeardman.com

14 October 2026 14:43

Marvelling how Bubble Bobble (Arcade) ran a tiny cooperative multitasker in its Z80's RST vectors: a handful of tasks, each with its own stack. Every vblank it wakes tasks whose timers hit 0; tasks yield to share the CPU. Coroutines in mere bytes! WHAT A GAME. Surely the GOAT 🐐