Difference between revisions of "Sega Mega Drive/Hardware revisions"
From Sega Retro
(→Model 1: VA7) |
(→Model 2: Expanded some sections) |
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*Z80 memory: [NUMBER PLEASE] (8Kx8 SRAM) | *Z80 memory: [NUMBER PLEASE] (8Kx8 SRAM) | ||
*Main ASIC: Sega 315-5660 | *Main ASIC: Sega 315-5660 | ||
| + | *Amplifier: BA10324AF | ||
}} | }} | ||
{{SectionsNew | {{SectionsNew | ||
| name=VA2 (USA) | | name=VA2 (USA) | ||
| image=PC BD MD2 VA2 USA.jpg | | image=PC BD MD2 VA2 USA.jpg | ||
| − | | desc= This revision | + | | desc=Components: |
| + | *M68K CPU: Motorola MC68HC000FN12 | ||
| + | *M68K memory: Sanyo LC331632M-12 | ||
| + | *Z80 CPU: Zilog Z84C0006FEC | ||
| + | *Main ASIC: Sega 315-5786 | ||
| + | *Amplifier: Sega 315-5684 | ||
| + | *FM synthesizer: Yamaha YM2612 | ||
| + | |||
| + | This revision (and the VA2.3) is the only Model 2 boards with a discrete YM2612 chip. | ||
| + | |||
| + | Additional circuitry is present on the daughterboard located on the PCB, with model number 171-6961A. | ||
}} | }} | ||
{{SectionsNew | {{SectionsNew | ||
| name=VA2.3 (USA) | | name=VA2.3 (USA) | ||
| image=PC BD MD2 VA2.3 USA.jpg | | image=PC BD MD2 VA2.3 USA.jpg | ||
| − | | desc= This revision | + | | desc=Components: |
| + | *M68K CPU: Motorola MC68HC000FN12 | ||
| + | *M68K memory: Toshiba TC511632FL-10 (32Kx16 PSRAM, 100 ns) | ||
| + | *Z80 CPU: Zilog Z84C0006FEC | ||
| + | *Z80 memory: KM78128LG-7 (8Kx8 SRAM) | ||
| + | *Main ASIC: Sega 315-5685 | ||
| + | *Video Encoder: Sony CXA1645M | ||
| + | *Amplifier: Sega 315-5684 | ||
| + | *FM synthesizer: Yamaha YM2612 | ||
| + | |||
| + | This revision (and the VA2) is the only Model 2 boards with a discrete YM2612 chip. | ||
}} | }} | ||
{{SectionsNew | {{SectionsNew | ||
| name=VA3 | | name=VA3 | ||
| image=PC_BD_MD2_VA3_USA_HAL.JPG | | image=PC_BD_MD2_VA3_USA_HAL.JPG | ||
| − | | desc= | + | | desc=Components: |
| + | *M68K CPU: Motorola MC68HC000FN12 | ||
| + | *M68K memory: ??? 651632DFP-15 | ||
| + | *Z80 CPU: Zilog Z84C0006FEC | ||
| + | *Main ASIC: Sega 315-5660 | ||
| + | *Video Encoder: Sony CXA1645M | ||
| + | *Amplifier: Sega 315-5684 | ||
}} | }} | ||
{{SectionsNew | {{SectionsNew | ||
Revision as of 04:24, 23 February 2023
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Model 1
|
VA0 (JPN) |
|---|---|
Components:
Due to a last-minute issue with the VDP in H40 mode, additional clock circuitry had to be added during manufacturing. This circuitry is present on a daughterboard in the center of the PCB, and contains the master oscillator (53.6931 MHz, NTSC), a 74LS74 (dual D-type flip-flops), and two 74LS161s (4-bit counter). An issue in the hardware causes the RAM memory to not completely initialize when the game starts, causing crashes in Osomatsu-kun Hachamecha Gekijou. | |
.JPG)
|
VA1 (JPN) |
Components:
| |
|
VA2 (USA, High Definition Graphics) |
Components:
| |
|
VA3 (USA, High Definition Graphics) |
Components:
| |
|
VA4 (JPN) |
Components:
| |
|
VA4 (PAL) |
Components:
| |
|
VA5 (JPN) |
|
VA6 (JPN) |
| The first Japanese revision with the TMSS. | |
|
VA6 (USA, High Definition Graphics) |
Components:
| |
|
VA6.5 (PAL) |
| This model removed the Mega Modem port | |
|
VA6.8 |
|
VA7 (USA) |
Components:
A function on the VDP has broken PAL 50Hz support. |
Model 2
|
VA0 (JPN) |
|---|---|
|
VA0 (PAL) |
|
VA0 (USA) |
Components:
| |
|
VA1 (USA) |
|
VA1 (PAL) |
Components:
| |
|
VA1.8 (USA) |
| PCB Printed by SKS
Components:
| |
|
VA1.8 (USA) |
| PCB Printed by CMK
Components:
| |
|
VA1.8 (PAL) |
Components:
| |
|
VA1.8 (Asia) |
Components:
| |
|
VA2 (USA) |
Components:
This revision (and the VA2.3) is the only Model 2 boards with a discrete YM2612 chip. Additional circuitry is present on the daughterboard located on the PCB, with model number 171-6961A. | |
|
VA2.3 (USA) |
Components:
This revision (and the VA2) is the only Model 2 boards with a discrete YM2612 chip. | |
|
VA3 |
Components:
| |
|
VA4 |
Components:
This is the first Mega Drive board without any discrete CPUs. Both the 68000 and Z80 are contained with the Sega 315-5960 ASIC, as well as the VDP, YM2612, and I/O controllers. |
Model 3
|
VA1 (USA) |
|---|---|
Components:
IC3 and IC4 markings are silkscreened but don't correspond to any physical ICs. | |
|
VA2 (USA) |
Components:
|