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$4800 DECOMPRESSED DATA CONTINUOUS READ PORT: returns a decompressed value from bank $50 and decrements 16 bit counter value at $4809/A by 1
$4801 COMPRESSED DATA TABLE POINTER: ($0000FF) low offset, defval:00
$4802 COMPRESSED DATA TABLE POINTER: ($00FF00) high offset, defval:00
$4803 COMPRESSED DATA TABLE POINTER: ($FF0000) bank, defval:00
$4804 COMPRESSED DATA TABLE INDEX: index of 32 bit compressed data pointer (big-endian), defval:00
$4805 DECOMPRESSED DATA OFFSET: ($00FF) low byte of offset in bank $50, defval:00
$4806 DECOMPRESSED DATA OFFSET: ($FF00) high byte of offset in bank $50, defval:00
$4807 DMA CHANNEL FOR DECOMPRESSION, set to match snes dma channel used for compressed data, defval:00
Now this could be enough for me to start and decompress chunks of compressed data while disassembling code, but for some reason the info above seem to be not accurate if not totally wrong. I tried tracing portions of code from Star Ocean just to find out where the compressed data could be, but it seems like those ports aren't used at all for what they are described (I can't even find 4805 in my traces). I even tried looking into Bsnes' code, but it didn't work for me. So anybody has more accurate/better understandable info on the S-DD1 communication with the Snes?$4801 COMPRESSED DATA TABLE POINTER: ($0000FF) low offset, defval:00
$4802 COMPRESSED DATA TABLE POINTER: ($00FF00) high offset, defval:00
$4803 COMPRESSED DATA TABLE POINTER: ($FF0000) bank, defval:00
$4804 COMPRESSED DATA TABLE INDEX: index of 32 bit compressed data pointer (big-endian), defval:00
$4805 DECOMPRESSED DATA OFFSET: ($00FF) low byte of offset in bank $50, defval:00
$4806 DECOMPRESSED DATA OFFSET: ($FF00) high byte of offset in bank $50, defval:00
$4807 DMA CHANNEL FOR DECOMPRESSION, set to match snes dma channel used for compressed data, defval:00
\ Some older emulator source that required the graphics packs might also help or be easier to understand.