Sega Mega Drive/Hardware revisions

From Sega Retro

Model 1

VA0 (JPN)

Megadrive JPN VA0 Serial No - 98M10036.jpg

Components :

  • M68K CPU: Signetics SCN68000C8N64
  • M68K memory: 2x HM65256BLSP-15 (32Kx8 PSRAM, 150 ns)
  • Z80 CPU: Zilog Z0840004PSC
  • Z80 memory: TMM2063P - 10 (8Kx8 SRAM, 100 ns)
  • I/O chips: Sega 315-5308, Sega 315-5309, Signectic 74LS00N, 74LS161AN, 74F161AN, 74LS74AN (DIP-16)
  • VDP: Sega 315-5313 (Yamaha YM7101)
  • Video RAM: 2x HM53461ZP-12 (64Kx4 DRAM 120ns)
  • Headphone amp: Sony CXA1034
  • Video encoder: Sony CXA1145
  • FM synthesizer: Yamaha YM2612

VA1 (JPN)

Megadrive VA1 Produced unit 99N83420 (JPN).JPG

Components:

  • M68K CPU: Signetics SCN68000C8N64
  • M68K memory: 2x TC51832SPL-10 (32Kx8 PSRAM, 100 ns)
  • Z80 CPU: Zilog Z0840004PSC
  • Z80 memory: NEC D4168C-20 (8Kx8 XRAM, 200 ns)
  • I/O chips: Sega 315-5308, Sega 315-5309, Sega 315-5345 (DIP-16)
  • VDP: Sega 315-5313 (Yamaha YM7101)
  • Video RAM: 2x HM53461ZP-12 (64Kx4 DRAM 120ns)
  • Headphone amp: Sony CXA1034
  • Video encoder: Sony CXA1145
  • FM synthesizer: Yamaha YM2612
  • Capacitors : TK Japan

VA2 (USA, High Definition Graphics)

MD1 IC BD M5 USA VA2.jpg

Components:

  • M68K CPU: Signetics SCN68000C8N64
  • M68K memory: 2x TC51832SPL-12 (32Kx8 PSRAM, 120 ns)
  • Z80 CPU: Zilog Z0840004PSC
  • Z80 memory: NEC D4168C-15 (8Kx8 XRAM, 150 ns)
  • I/O chips: Sega 315-5308, Sega 315-5309, Sega 315-5345 (DIP-16)
  • VDP: Sega 315-5313 (Yamaha YM7101)
  • Video RAM: 2x [NUMBER PLEASE] (64Kx4 DRAM)
  • Headphone amp: Sony CXA1034
  • Video encoder: Sony CXA1145
  • FM synthesizer: Yamaha YM2612

VA3

VA4 (PAL)

IC BD M5 PAL VA4.jpg

VA5

VA6 (USA, High Definition Graphics)

MD1 IC BD M5 USA VA6.jpg

Components:

  • M68K CPU: Motorola MC68000P8
  • M68K memory: 2x HM652568LSP-10 (32Kx8 PSRAM, 100 ns)
  • Z80 CPU: Zilog Z0840004PSC
  • Z80 memory: MB8464A-10 (8Kx8 SRAM, 100 ns)
  • I/O chip: Sega 315-5433
  • VDP: Sega 315-5313 (Yamaha YM7101)
  • Video RAM: 2x [NUMBER PLEASE] (64Kx4 DRAM)
  • Headphone amp: Sony CXA1034
  • Video encoder: Sony CXA1145P
  • FM synthesizer: Yamaha YM2612

VA6 (PAL)

MD1 IC BD M5 PAL VA6.jpg

VA6.8

VA7 (USA)

PC BD M5 USA VA7.jpg

Model 2

VA0 (PAL)

PC BD MD2 VA0 PAL.jpg

VA1 (USA)

MD2 US PCB Top VA1.jpg

VA1 (PAL)

Components:

  • M68K CPU: Motorola MC68HC000FN8
  • M68K memory: Sanyo LC331632M-12
  • Z80 CPU: Toshiba 84C00AU-6
  • Main ASIC: Sega 315-5660
  • Video Encoder: Fujitsu MB3514

VA1.8 (USA)

PC BD MD2 VA1.8 USA.JPG

VA1.8 (PAL)

PC BD MD2 VA1.8 PAL.jpg

VA1.8 (Asia)

PC BD MD2 VA1.8 ASIA.jpg

Components:

  • M68K CPU: Motorola MC68HC000FN8
  • M68K memory: Toshiba TC511632FL-10 (32Kx16 PSRAM, 100 ns)
  • Z80 CPU: Toshiba 84C00AU-6
  • Z80 memory: [NUMBER PLEASE] (8Kx8 SRAM)
  • Main ASIC: Sega 315-5660

VA1.8

VA2

VA2.3

VA3

PC BD MD2 VA3 USA HAL.JPG

VA4

PC BD MD2 VA4 171 - 7229B - 11.JPG

Model 3

VA1 (USA)

VA2 (USA)

PC BD MD3 VA2 USA.jpg

Components:

  • Main ASIC: Sega 315-6123 (contains M68K, Z80, VDP, YM2612, and probably some other components.)
  • Memory (right of main ASIC): NEC D4502161G5 (128Kx16 SDRAM)
  • Oscillator (bottom-right of main ASIC): SG53 PTR S 53.6931M
  • Video Encoder (bottom-left of main ASIC): Sony CXA1645M
  • Amplifier (left of main ASIC): TI 85AFTRF LM324