Sega Mega Drive/Hardware revisions

From Sega Retro

Model 1

VA0

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

VA1.8 (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
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