The MagicSound board from Patisonic is a 4-channel DMA sound expansion for the Aleste 520EX from the same company.
The Aleste 520EX is a rare CPC 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 Overview
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 Controller 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
Magic Sound Chipset
pcs russian western name description 1 KR1810WT37 8237 D5 DMA controller 2 KR1810WI54 8254 D3,D4 Programmable interval timer 1 K1118PA1 MC10318 D21 8bit digital-analog-converter 2 K555AP6 74LS245 D1,D2 8bit 3state transceiver 1 K555ID4 74LS155 D14 2x2bit decoder/demult 1 K555IR22 74LS373 D6 8bit 3state latch 4 K555IR32 74LS170 D7,D8,D9,D10 4x4bit register file OC 1 K555KP11 74LS257 D16 8-to-4 data selector 2 K555LI1 74LS08 D18,D20 Quad AND gates 1 K555LL1 74LS32 D19 Quad OR gates 1 K555LN1 74LS04 D17 Hex inverters 2 K555RU2 xxx D12,D11 16x4bit RAM with separate data in/out 1 K555TR2 74LS279 D13 Quad Set-Reset Latches 2 K555TM2 74LS74 D15,D25 Dual flipflop 1 K561KP1 4052 D22 8-to-2 line analog multiplexer 2 K561KT3 4066 D23,D24 Quad analog switches
In the schematics, all chips are on sheet1, except, D21..D24 on sheet2.