UM6558 and UM6559 pinout
UM6558 is PPU with additional 8 pins (CD0..CD7) that are used to output currently rendered pixel color.
.--\/--.
R/W -> |01 48| -- +5V
CPU D0 <> |02 47| -> ALE
CPU D1 <> |03 46| <> PPU AD0
CPU D2 <> |04 45| <> PPU AD1
CPU D3 <> |05 44| <> PPU AD2
CPU D4 <> |06 43| <> PPU AD3
CPU D5 <> |07 42| <> PPU AD4
CPU D6 <> |08 41| <> PPU AD5
CPU D7 <> |09 40| <> PPU AD6
* /CS -> |10 39| <> PPU AD7
* CPU A2 -> |11 38| -> PPU A8
* CPU A1 -> |12 37| -> PPU A9
* CPU A0 -> |13 36| -> PPU A10
GND ?? |14 35| -> PPU A11
GND ?? |15 34| -> PPU A12
GND ?? |16 33| -> PPU A13
GND ?? |17 32| -> /RD
* VCC ?? |18 31| -> /WR
* CLK -> |19 30| -> CD0 *
* /INT <- |20 29| -> CD1 *
* /RST -> |21 28| -> CD2 *
* CD7 <- |22 27| -> CD3 *
* CD6 <- |23 26| -> CD4 *
* GND -- |24 25| -> CD5 *
'------'
- = difference with respect to the common 40-pin PPU pinout
UM6559 is DAC that is capable of generating RED/GREEN/BLUE/SYNC/CHROMA/LUMA signals from of the CD0..CD7 values
.--\/--.
CD4 -> |01 24| <- CD3
CD5 -> |02 23| <- CD2
+5V -- |03 22| <- CD1
A1 -> |04 21| <- CD0
A2 -> |05 20| -- GND
LUMA <- |06 19| <- BIAS
?? NC -> |07 18| -> BLUE
SYNC <- |08 17| -> GREEN
CD6 -> |09 16| -> RED
CD7 -> |10 15| -- +5V
CLK -> |11 14| -> CHROMA
GND -- |12 13| -> NC ??
'------'
Sources: