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Sega Mega Drive Motherboard revisions

Model 1Edit

VA1 [IC BD M5 VA1]Edit

IC BD M5 VA1
List of IC's
IC# Brand Name Description Documentation
IC1 Signetics SCN68000C8N64 8MHz Processor -
IC2/IC3 Toshiba TC51832SPL-12 CMOS 256K (32K x 8) Pseudo-SRAM, 12ns -
IC4 SEGA 315-5308 I/O chip -
IC5 SEGA 315-5309 I/O chip -
IC6 Zilog Z0840004PSC Zilog Z80 8-bit coprocessor -
IC7 NEC D4168C-15-SG 64K (8,192 x 8-BIT) NMOS XRAM -
IC8 SEGA 315-5313 (Yamaha YM7101) VDP -
IC9/IC10  ?  ? Video 256K (64K x 4) DRAM -
IC11 Yamaha YM2612 frequency modulation synthesizer -
IC12 Sony CXA1034 Headphone amp -
IC13  ?  ?  ? -
IC14  ?  ?  ? -
IC15  ?  ?  ? -
IC16 Sega 315-5339 (DIP16) I/O chip -


VA2 [IC BD M5 USA VA2] 837-6992Edit

IC BD M5 USA VA2
List of IC's
IC# Brand Name Description Documentation
IC1 Signetics SCN68000C8N64 8MHz Processor -
IC2/IC3 Toshiba TC51832SPL-12 CMOS 256K (32K x 8-bit) Pseudo-SRAM, 12ns -
IC4 SEGA 315-5308 I/O chip -
IC5 SEGA 315-5309 I/O chip -
IC6 Zilog Z0840004PSC Zilog Z80 8-bit coprocessor -
IC7 NEC D4168C-15 64K (8K x 8) NMOS XRAM, 150 ns -
IC8 SEGA 315-5313 (Yamaha YM7101) VDP -
IC9/IC10 Samsung & NEC KM424C64Z-10 & D41264V-12 256K (64K x 4-bit) VRAM & Dual-Port Graphics Buffer -
IC11 Yamaha YM2612 frequency modulation synthesizer (Sound Chip) HERE
IC12 Sony A1034(CXA1034P/M) Headphone amp HERE
IC13 Sony CXA1145 Video encoder HERE
IC14 Hitachi HA17358 dual operational amplifier HERE
IC15/IC17  ? 7805 +5V Regulator -
IC16 Sega 315-5345 (DIP16) I/O chip -


VA3 [IC BD M5 USA VA3] 837-7071Edit

List of IC's
IC# Brand Name Description Documentation
IC1 Signetics SCN68000C8N64 8MHz Processor -
IC2/IC3 Toshiba TC51832SPL-12 CMOS 256K (32K x 8) Pseudo-SRAM, 12ns -
IC4 SEGA 315-5364 I/O chip -
IC5 SEGA 315-5309 I/O chip -
IC6 Zilog Z0840004PSC Zilog Z80 8-bit coprocessor -
IC7 NEC D4168C-15-SG 8,192 x 8-BIT NMOS XRAM, 150 ns -
IC8 SEGA 315-5313 I/O chip -
IC9/IC10 Fujitsu MB81461-12 256K (64K x 4-bit) VRAM -
IC11 |YM2612 frequency modulation synthesizer -
IC12 Sony CXA1034 Headphone amp -
IC13 Sony CXA1145P RGB Encoder -
IC14  ? LM358N Dual Operational Amplifier -


VA4 [IC BD M5 PAL VA4]Edit

List of IC's
IC# Brand Name Description Documentation
IC1 Motorola MC68000P8 8MHz Processor -
IC2/IC3 Hitachi HM65256BLSP-10 256Kb (32Kx8) Psuedo Static RAM, 100ns -
IC4 SEGA 315-5364 I/O chip -
IC5 SEGA 315-5309 I/O chip -
IC6 Zilog Z0840004PSC Zilog Z80 8-bit coprocessor -
IC7 Sanyo LC3664RL 64Kb (8Kx8) NMOS Static RAM, 120ns -
IC8 SEGA 315-5313 I/O chip -
IC9/IC10 Fujitsu MB81461-12 256K (64K x 4-bit) VRAM -
IC11 Yamaha YM2612 frequency modulation synthesizer -
IC12 Sony CXA1034P Headphone amp -
IC13 Sony CXA1145P RGB Encoder -
IC14 Ti LM358P Dual Operational Amplifier -


VA5Edit

The only difference is the IC4 315-5402


VA6 [IC BD M5 PAL]Edit

Genesis pal model1 M5
List of IC's
IC# Brand Name Description Documentation
IC1 Hitachi HD68HC000P8 8MHz Processor -
IC2/IC3 Motorola MCM51L832ASP10 CMOS 1024 BIT SRAM -
IC4 SEGA 315-5433 I/O chip -
IC5 SEGA 315-5313A I/O chip -
IC6 Zilog Z0840004PSC Zilog Z80 8-bit coprocessor -
IC7 Fujitsu MB8464A-10LL-SK CMOS 65,536 SRAM -
IC8  ?  ?  ? -
IC9/IC10 Fujitsu MB81461-12SL 256k 120ns Video RAM Dual Port -
IC11 Yamaha YM2612 Audio -
IC12 SONY CXA1034P Amplifier -
IC13 SONY CXA1145P Video -
IC14  ?  ?  ? -


VA6 [IC BD M5 USA VA6]Edit

List of IC's
IC# Brand Name Description Documentation
IC1 Motorola MC68000P8 8MHz Processor -
IC2/IC3 Motorola MCM51L832ASP10 256Kb (32K x 8-bit) SRAM -
IC4 SEGA 315-5433 I/O chip -
IC5 SEGA 315-5313A I/O chip -
IC6 Zilog Z0840004PSC Zilog Z80 8-bit coprocessor -
IC7 Samsung KM6264BL-10 64Kb: (8K x 8-bit) SRAM -
IC8 SEGA 315-5313 I/O chip -
IC9/IC10 Samsung & NEC KM424C64Z-10 & D41264V-12 256K (64K x 4-bit) VRAM & dual-port graphics buffer -
IC11 Yamaha YM2612 Audio -
IC12 SONY CXA1034P Headphone Amplifier -
IC13 SONY CXA1145P RGB Video -
IC14 Hitachi HA17358 Dual operational amplifier -
IC15/17  ? 7805 +5 Voltage Regulator -


VA6.8Edit


VA7 [PC BD M5 USA VA7] 171-6217-11Edit

PC BD M5 USA VA7

The VA7 is almost a Genesis 2 PCB in a Genesis 1 case. It even shares the same PCB prefix (PC).

List of IC's
IC# Brand Name Description Documentation
IC1 Motorola MC68HC000FN8 Processor -
IC2/IC3 Hitachi HM65256BLFP-10T CMOS 256K (32K x 8) High Speed Pseudo-Static RAM HERE
IC4 Zilog Z0840004PSC Zilog Z80 8-bit coprocessor -
IC5 Fujitsu MB8464A-10L 64K (8192 words x 8 bits) Low Power SRAM -
IC6 SEGA 315-5487-01 I/O, Bus arbiter, VDP, ym2612, TMSS -
IC7/IC8 Hitachi HM53461ZP-12SG 65,536-WORDx4-bit Multiport CMOS video ram HERE
IC9/IC10 Rohm BA10324AF Op-amp HERE
IC11 SONY CXA1145M Video -
IC12 Toshiba TA7805S +5V Voltage regulator -


List of Electrolytic Capacitors
CE# Capacitance Voltage
CE1 10 μF 16 V
CE2 10 μF 16 V
CE3 10 μF 16 V
CE4 10 μF 16 V
CE5 10 μF 16 V
CE6 10 μF 16 V
CE7 10 μF 16 V
CE8 10 μF 16 V
CE9 220 μF 10 V
CE10 220 μF 10 V
CE11 10 μF 16 V
CE12 220 μF 10 V
CE13 10 μF 16 V
CE14 10 μF 16 V
CE15 10 μF 16 V
CE16 220 μF 16 V
CE17 100 μF 10 V
CE18 47 μF 10 V
CE19 47 μF 10 V
CE20 10 μF 16 V
CE21 10 μF 16 V
CE22 10 μF 16 V
CE23 100 μF 10 V
CE24 47 μF 10 V
CE25 47 μF 10 V
CE26 47 μF 10 V
CE27 47 μF 10 V
CE28 47 μF 10 V
CE29 10 μF 16 V
CE30 10 μF 16 V
CE31 100 μF 10 V
Totals
17 10 μF 16 V
7 47 μF 10 V
3 100 μF 10 V
4 220 μF 10 V

Model 2Edit

VA0 PALEdit


VA1 [PC BD MD2 VA1 USA]Edit

Model2 va1 motherboard
List of IC's
IC# Brand Name Description Documentation
IC1 Motorola MC68HC000FN8 Processor -
IC2 Toshiba TC511632FL-10 65,536 Word x 16 Bit Dynamic Ram -
IC3  ?  ?  ? -
IC4 SEGA 315-5678 (?)  ? -
IC5 Fujitsu M88464A-10L 8K Words x 8-Bit (64K) CMOS SRAM Low Power -
IC6 SEGA 315-5660  ? -
IC7 OKI M54C864-80 65,536-Word x 8-Bit Multiport DRAM -
IC8  ?  ?  ? -
IC9/IC10  ? LM324 Low power quad op amps -
IC11 SONY CXA1145M Video (RGB Encoder) HERE
IC12  ?  ? Voltage regulator -


VA1 [PC BD MD2 VA1 PAL]Edit

List of IC's
IC# Brand Name Description Documentation
IC1 Motorola MC68HC000FN8 Processor -
IC2 Toshiba TC511632FL-10 65,536 Word x 16 Bit Dynamic Ram -
IC3  ?  ?  ? -
IC4 Toshiba 84C00AU-6 Z80 clone -
IC5 Fujitsu MB8464H-10LL 8K Words x 8-Bit (64K) CMOS SRAM Low Power -
IC6 SEGA 315-5660  ? -
IC7 OKI M54C864-80 65,536-Word x 8-Bit Multiport DRAM -
IC8  ?  ?  ? -
IC9/IC10 Rohm BA10324AF Low power quad op amps -
IC11 Fujitsu MB3514 Video (RGB Encoder) -
IC12  ?  ? Voltage regulator -


VA1 [PC BD MD2 VA1 ASIA]Edit

2016-04-08 17.54.49 cr
List of IC's
IC# Brand Name Description Documentation
IC1 Motorola MC68HC000FN8 Processor -
IC2 Toshiba TC511632FL-10 512K (32K x 16-bit) PSRAM, 100 ns -
IC4 Toshiba 84C00AU-6 Z80 8-bit coprocessor -
IC5 Sanyo LC3664BML-10 64K (8Kx8-bit) SRAM -
IC6 Sega 315-5660 I/O, Bus arbiter, VDP, ym2612, TMSS -
IC7 Hitachi HM53861J-8 512K (64K x 8-bit) VRAM -
IC9/IC10 Taxes Instruments LM324 ground sense quad op-amp -
IC11 Fujitsu MB3514 RGB Encoder -
IC12 Voltage Regulator -

VA1.8 [PC BD MD2 VA1.8 USA]Edit

PC BD MD2 VA1.8 USA
List of IC's
IC# Brand Name Description Documentation
IC2 Hitachi / Sanyo 651632DFP-15 / LC331632M-12 512K (32K x 16-bit) SRAM -
IC3  ?  ?  ? -
IC4 Zilog Z84C0006FEC Zilog Z80 8-bit coprocessor -
IC5 Rohm XLJ6265AF-10SL 64K (8K x 8-bit) CMOS SRAM -
IC6 SEGA 315-5660 Custom I/O chip -
IC7 Samsung KM428C64J-10 512K (64K x 8-bit) VRAM -
IC8  ?  ?  ? -
IC9/IC10 Rohm BA10324AF ground sense quad op-amp -
IC11 Sony / Samsung CXA1145M / KA2195D RGB Encoder NTSC+PAL / NTSC only HERE
IC12  ? 7805 +5V Voltage regulator -


VA1.8 [PC BD MD2 VA1.8 PAL]Edit

Genesis pal model2 VA1.8
List of IC's
IC# Brand Name Description Documentation
IC1 Motorola MC68HC000FN8 Processor -
IC2  ? 651632DFP-15 512K (32K x 16-bit) SRAM -
IC3  ?  ?  ? -
IC4 Zilog Z84C0006FEC Zilog Z80 8-bit coprocessor -
IC5 Rohm BR6265BF-10SL 64K (8K x 8-bit) CMOS SRAM -
IC6 SEGA 315-5660 Custom I/O chip -
IC7 Hitachi HM53861J-8 512K (64K x 8-bit) VRAM -
IC8  ?  ?  ? -
IC9/IC10 Rohm BA10324AF ground sense quad op-amp -
IC11 Fujitsu MB3514 RGB Encoder HERE
IC12  ? 7805 +5V Voltage regulator -


VA1.8 [PC BD MD2 VA1.8 ASIA]Edit

PC BD MD2 VA1.8 ASIA
List of IC's
IC# Brand Name Description Documentation
IC1 Motorola MC68HC000FN8 Processor -
IC2 Toshiba TC511632FL-10 512K (32K x 16-bit) PSRAM, 100 ns
IC3  ?  ?  ? -
IC4 Toshiba 84C00AU-6 Z80 8-bit coprocessor -
IC5  ?  ? 64K (8Kx8-bit) SRAM -
IC6 Sega 315-5660 -
IC7 Hitachi HM53861J-8 512K (64K x 8-bit) VRAM -
IC8  ?  ?  ? -
IC9/IC10 Rohm BA10324AF ground sense quad op-amp -
IC11 Fujitsu MB3514 RGB Encoder -
IC12 7805 Voltage Regulator -


VA2 [PC BD MD2 VA2 USA]Edit

List of IC's
IC# Brand Name Description Documentation
IC1 Motorola MC68HC000FN12 Processor
-
IC2 Sanyo LC331632M-12 512K (32768 words X 16 bits) Pseudo-SRAM
IC3 Rohm BA10358 Dual ground sense operational amplifier -
IC4 Zilog Z84C0006FEC Zilog Z80 8-bit coprocessor -
IC5  ? XL J6265AF-10SL -
IC6 Sega 315-5786 (Toshiba T9N13BF) -
IC7 Samsung KM428C64J-10 64K x 8 Bit CMOS Video RAM
-
IC8 Yamaha YM2612 frequency modulation synthesize -
IC9/IC10 -
IC11 Voltage Regulator -
IC12 Sega 315-5684 (Rohm BA6166FS) SOUND NETWORK/HEADPHONE AMP -
IC13 Sanken SKA2195D RGB Encoder -


VA2.3 PC BD MD2 VA2.3 USAEdit

MD2VA2-3 452018272
List of IC's
IC# Brand Name Description Documentation
IC1 Motorola MC68000FN12 Processor -
IC2 Toshiba TC511632FL-10 512K (32768 words X 16 bits) Pseudo-SRAM -
IC3 Rohm BA10358 Dual ground sense operational amplifier -
IC4 Zilog Z84C0006FEC Zilog Z80 8-bit coprocessor -
IC5  ? XL J6265AF-10SL 4K (8K x 8-bit) CMOS SRAM -
IC6 Sega 315-5786 (Toshiba T9N13BF) VDP and IO chip all-in-one. Doesn't include the YM2612. Used on MD2 VA2 and VA2.3 board revisions. -
IC7 Toshiba TC5281286J-80 1M (128K x 8-bit) VRAM -
IC8 Yamaha YM2612 frequency modulation synthesize -
IC9 SEGA 315-5684 (Rohm BA6166FS) SOUND NETWORK / HEADPHONE AMP -
IC11 Sony CXA1645M RGB Encoder -
IC12  ? 7805 +5V voltage regulator -
IC13  ? 74HC14 HEX SCHMITT-TRIGGER INVERTER -


VA3 [PC BD MD2 VA3 USA HAL]Edit

PC BD MD2 VA3 USA HAL
List of IC's
IC# Brand Name Description Documentation
IC1 Motorola MC68HC000FN8 Processor -
IC2 Hitachi(?) 651632DFP-15 512K (32K X 16-bits) Pseudo-SRAM -
IC3  ?  ?  ? -
IC4 Zilog Z84C0006FEC Zilog Z80 8-bit coprocessor -
IC5  ?  ? 64K (8K x 8-bit) SRAM -
IC6 Sega 315-5660 VDP and IO chip all-in-one. -
IC7 OKI M54C864-80 512K (64K x 8-bit) VRAM -
IC8  ?  ?  ? -
IC9 SEGA 315-5684 (Rohm BA6166FS) SOUND NETWORK / HEADPHONE AMP -
IC10  ?  ?  ? -
IC11 Samsung KA2195D RGB Encoder -
IC12  ? 7805 +5V Voltage Regulator -


VA4 [PC BD MD2 VA4]Edit

GEN2 VA4 MK1451

Model 3Edit

VA1Edit

VA2Edit

NotesEdit

Most of the time the main SEGA IC's are based on/renamed chips from other brands as follows:

  • MD1 VA0, VA1, VA2, VA3, VA4, VA5, VA6, VA6.8
Yamaha YM7101 / FC1001 = Sega 315-5313 / 315-5313A / 315-5313A-01
  • MD1 VA7 & MD2 VA0, VA1, VA1.8, VA3
Yamaha FC1004 = Sega 315-5487 / 315-5487-01 / 315-5487-10 / 315-5660 / 315-5660-02 / 315-5708 / 315-5708-01
Yamaha FF1004 = Sega 315-5700
  • MD2 VA2, VA2.3
Toshiba T9N13BF = Sega 315-5786
Toshiba TC6158AF = ???
  • MD2 VA4 & GEN3 VA1
Yamaha FJ3002 = Sega 315-5960
  • GEN3 VA2
Yamaha FQ8007 = Sega 315-6123

See AlsoEdit

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