Changes
The '''Aleste 520EX''' is a rare CPC [[Clones|clone]] with 512Kbyte RAM, its expansion port includes some additional pins allowing external hardware to access the 512K RAM via DMA. The '''MagicSound''' board is probably even rarer, it's using the additional DMA pins on the expansion port, so it works only on the Aleste, not on normal CPCs.
== I/O Map and NMI ==
Port A10 A9 A8 A5 A3 A2 A1 A0 RW Expl.
FXDX 0 X X 0 X X X X The board selected.
F8DX 0 0 0 0 r r r r RW DMA 8237
rrrr is reg number
D[7..0] Data
F9DX 0 0 1 0 1 0 r r -W TIMER 8254 CHANNELS 0,1,2
rr is reg number
D[7..0] Data
F9DY 0 0 1 0 0 1 r r -W TIMER 8254 CHANNELS 3, and DAC
nn is reg number
D[7..0] Data
FADX 0 1 0 0 X X c c -W VOLUME CONTROL
cc is channel number
D[5..0] Volume
FBDX 0 1 1 0 c c m m -W MAPPER
cc is channel number
mm is mapper's page register
D[5..0] inverted page number
After reset timers do not work until first write to it's regs
After dma end ('tc' signal) the NMI to Z80 generated
== Pictures ==
