mrmacete
Matthew GarrettI suddenly need to care about Amiga DMA cycle timings and this isn't an improvement in my quality of life
Is there a diagram anywhere of exactly where the DMA cycles occur during horizontal scanout?
💬@mjg59 is there any useful info in Moira? https://github.com/dirkwhoffmann/moira (a m68k emulator written for Amiga emulation, specifically including DMA timings)
@rfc6919 Oh that's an excellent idea to check!
Ben Hutchings@mjg59 It's in the Hardware Reference Manual https://archive.org/details/amiga-hardware-reference-manual-3rd-edition/ page 195 ( or page 199 depending on how you count)
Amiga Hardware Reference Manual 3rd Edition : Commodore-Amiga Inc. : Free Download, Borrow, and Streaming : Internet Archive
AMIGA TECHNICAL REFERENCE SERIESIntroductionCoprocessor hardwarePlayfield hardwareSprite hardwareAudio hardwareBlitter hardwareSystem Control hardwareInterface...
@mjg59 Btw I think it's possible to turn off bitplane DMA and poke the data directly into the BPLnDAT registers, but this is not documented and the timing would be very challenging
Paul Evans@mjg59 Weird how these two posts popped up right next to each other
(The other post is https://hackaday.social/@hackaday/115008369791263180)