Quadruple 245 with additional OR and AND gates. Predecessor of NEO-BUF.
Schematic is wrong: A and B sides are flipped !
- Pin 51 is enable for MCD0~MCD15
- Pin 39 is enable for PALD0~PALD15
- Pin 40 is direction select for D0~D7
- Pin 52 is direction select for D8~D15
Palette RAM and memory card access. Palette RAM /WE and P1 ROM /OE generation.
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- D0~D15: 68k data bus
- PALD0~PALD7: Lower palette RAM data bus
- PAUD0~PAUD7: Upper palette RAM data bus
- MCD0~MCD15: Memory card data bus
- PAL: Palette RAM address decode from NEO-C1
- R/W: R/W from 68k
- PALWE: Palette RAM /WE, output made from PAL OR R/W
- ROMOEL, ROMOEU: from PRO-C0
- ROMOE: Cartridge P ROM /OE, output made from ROMOEU AND ROMOEL
J12: ADPCM buses access for both slots. 10 AS04: negated /ROE from YM2610, 12 AS04: negated /POE from YM2610. SLOT0, SLOT1: enables from NEO-F0. OpenOffice Draw file: File:Neo-g0 mv2b J12.odg
B7: Palette RAM and memory card access. Palette RAM /WE and System ROM /OE generation. 28 C0 (PAL ?):Palette RAM address decode from PRO-C0. OpenOffice Draw file: File:Neo-g0 mv2b C7.odg