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#bus-arbitration

3 posts

RetrogamingDeep Dive October 4, 2026 7 min read

Mega Drive Z80 Bus Handoff: BUSREQ, Reset, and Shared Sound RAM

Coordinate 68000 access to Mega Drive Z80 memory with BUSREQ polling, reset separation, byte-lane care, safe release, and reproducible audio-subsystem diagnostics.

#sega-genesis#z80#bus-arbitration

RetrogamingDeep Dive October 4, 2026 7 min read

Mega-CD Word RAM: 1M and 2M Modes, Ownership, and Safe Handoffs

Map Mega-CD Word RAM ownership in 1M and 2M modes, then design safe main/sub-CPU handoffs, access tests, and emulator state transitions.

#retrogaming#mega-cd#memory

RetrogamingDeep Dive October 4, 2026 8 min read

PlayStation DMA Controller: DPCR Priority, Chopping, and DICR Flags

Model PS1 DMA as seven timed channel engines with DPCR priority, synchronization modes, chopping windows, linked lists, and latched DICR flags.

#playstation#dma#dpcr