NEO-G0

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Revision as of 09:23, 23 November 2015 by Freem (talk | contribs) (BIOS -> system ROM)
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Quadruple 245 with OR and AND gates. Predecessor of NEO-BUF.

Internal logic

  • 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

AES pinout

Palette RAM and memory card access. Palette RAM /WE and P1 ROM /OE generation.

File:Neo-g0 aes pinout.png

OpenOffice Draw file: File:Neo-g0 aes.odg

  • 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

MV2B @ J4 pinout

68k data bus access for both slots.

OpenOffice Draw file: File:Neo-g0 mv2b J4.odg

  • D0~D15: 68k data bus
  • 1D0~1D15: Slot 1 68k data bus
  • 2D0~2D15: Slot 2 68k data bus
  • DS0,DS1: Slot 68k data enables from NEO-I0
  • R/W: R/W from 68k


MV2B @ J12 pinout

ADPCM buses access for both slots.

OpenOffice Draw file: File:Neo-g0 mv2b J12.odg

  • SDRAD0~SDRAD7: ADPCM-A data bus from YM2610
  • 1SDRAD0~1SDRAD7: ADPCM-A data bus for slot 1
  • 2SDRAD0~2SDRAD7: ADPCM-A data bus for slot 2
  • SDPAD0~SDPAD7: ADPCM-B data bus from YM2610
  • 1SDPAD0~1SDPAD7: ADPCM-B data bus for slot 1
  • 2SDPAD0~2SDPAD7: ADPCM-B data bus for slot 2
  • 10 AS04: negated /ROE from YM2610
  • 12 AS04: negated /POE from YM2610
  • SLOT0, SLOT1: enables from NEO-F0

MV2B @ C7 pinout

Palette RAM and memory card access. Palette RAM /WE and System ROM /OE generation.

OpenOffice Draw file: File:Neo-g0 mv2b C7.odg

Very similar connections with the one used in the AES.

  • 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
  • 28 C0 (PAL ?):Palette RAM address decode from PRO-C0
  • R/W: R/W from 68k
  • PALWE: Palette RAM /WE, output made from PAL OR R/W
  • SROMOEL, SROMOEU: from PRO-C0, System ROM byte /OE
  • ROMOE: System ROM ROM /OE, output made from SROMOEU AND SROMOEL