Sega Mega Drive/Hardware revisions
From Sega Retro
Contents
Model 1
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
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
Model 2
VA1.8: USA
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
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