Magic Sound Board

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

Pictures

• A Magic Sound board (with all components installed)
• 

  PCB front (solder side)

• 

  PCB rear (component side)

• 

  PCB mounted

• Another Magic Sound board (non-functional: the 3.5mm socket, and a lot of chips aren't installed)
• 

  PCB front (solder side)

• 

  PCB rear (component side)

Schematics

• 

  Schematic 1/2 (digital part)

• 

  Schematic 2/2 (analog part)

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.