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Jaleco SS88006 and ADPCM ICs
http://forums.nesdev.com/viewtopic.php?f=9&t=16304
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Author:  lidnariq [ Fri Aug 04, 2017 6:09 pm ]
Post subject:  Jaleco SS88006 and ADPCM ICs

I was taking a closer look at the various boards in NesCartDB that use the SS88006 and I think previous documentation about how the ADPCM IC playback works is probably wrong.

(For the record: boards JF-23, -24, -25, -29, -37 without battery+PRGRAM; -27, -40 with)

I'm have this strong hunch that writes to $F003 are latched on (at least) two of the pins on the SS88006, and those pins are connected to the µPD775x /PLAY and /RESET pins ... CPU D2 through D7 are connected to µPD775x I0 through I5

From tracing pictures of the PCB, I was able to get half the SS88006's pinout:
Code:
    M2 -> | 01  42 | -- +5
CPUA12 -> | 02
CPUA13 -> | 03
CPUA14 -> | 04
PRGA16 <- | 05
PRGA15 <- | 06  37 | -> /START
PRGA14 <- | 07
PRGA13 <- | 08
PRG/OE <- | 09
PRGA17 <- | 10
 ?a18? <- | 11
 CPUA1 -> | 12
 CPUA0 -> | 13
 CPUD0 -> | 14
 CPUD1 -> | 15
 CPUD2 -> | 16
  ?D3? -> | 17
   R/W -> | 18
/ROMSL -> | 19
  /IRQ <- | 20
   Gnd -- | 21


It'd be really nice if someone had the parts on hand to take a closer look ...

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