Sega Mega Drive/Hardware revisions

Model 1

	VA0 (JPN)
	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)
	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)
	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)
	VA5
	VA6 (USA, High Definition Graphics)
	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)
	VA6.8
	VA7 (USA)

Model 2

VA0 (PAL)

VA1 (USA)

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
• Amplifier: BA10324AF

VA1.8 (USA)

VA1.8 (PAL)

VA1.8 (Asia)

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

VA3

VA4

Model 3

VA2 (USA)

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