Sega Megadrive 2 PCB
Sega Megadrive 2 PCB
This is something I haven't seen before, Z80 and 68000 CPUs on the same motherboard.
There also seems to be 3 different types of memory chip and something likewise unusual that I've never seen, a capacitor array, next to the crystal.
Apparently the Z80 controls the sound output on this SMD version of the Megadrive, cost reduced and with reputedly lesser sound and picture on SCART.
I bought this cheap before Christmas to play Space Harrier, a type of game called a 'rail shooter'.
The original Space Harrier was released on Sega Master system and not on the Megadrive but Space Harrier II on 16-bit is comparable with the original and much better than the Spectrum version, the characters and background are indistinct and the screen is a bit stuffy in comparison with Megadrive/Master system.
There also seems to be 3 different types of memory chip and something likewise unusual that I've never seen, a capacitor array, next to the crystal.
Apparently the Z80 controls the sound output on this SMD version of the Megadrive, cost reduced and with reputedly lesser sound and picture on SCART.
I bought this cheap before Christmas to play Space Harrier, a type of game called a 'rail shooter'.
The original Space Harrier was released on Sega Master system and not on the Megadrive but Space Harrier II on 16-bit is comparable with the original and much better than the Spectrum version, the characters and background are indistinct and the screen is a bit stuffy in comparison with Megadrive/Master system.
Re: Sega Megadrive 2 PCB
the combination of 68000 for game program and z80 for sound was quite common in arcade video game pcb's back in the day
Last edited by lovebug on Tue Dec 26, 2023 8:44 am, edited 1 time in total.
Re: Sega Megadrive 2 PCB
This PCB lacks the serial port header on Megadrive PCBs, I don't know if any alternative ROM images exist for Megadrives, strikes me it's probably possible on an original Megadrive.
Edit: it's a modem port, not a serial port.
Edit: it's a modem port, not a serial port.
Re: Sega Megadrive 2 PCB
I've just noticed a broken track, near the top of the cart slot, so hopefully this board will be functional soon!
Re: Sega Megadrive 2 PCB
The megadrive also was completely back-compatible with the Master System, which had a Z80 CPU. The master system adapters were pretty much just a straight through for the the original cartridges.
Re: Sega Megadrive 2 PCB
That's a standard config for the MegaDrive, gives Master System compatibility and controls sound for the MD itself.
I have to be honest, I love Space Harrier, and the Master System is not the best place to play it, for me it's the Saturn, and I prefer that version over the Dreamcast version.
I really hope you can get that trace fixed and it up and running though.
Re: Sega Megadrive 2 PCB
I believe the Master cartridge adapter idles the 68000 and passes control to the 4 Mhz Z80, but apparently some games require a Master controller, not sure which.
Should be doable, just scrape the trace back a way from the break to ensure no shorting to the other tracks.
Re: Sega Megadrive 2 PCB
Although the motherboard in the picture powered on but didn't boot up, I had another similar PCB which did boot up!
Both my cartridges work,
the sound output on Sonic sounds OK on composite but Space Harrier sounds like it could use a sound upgrade,
Both my cartridges work,
the sound output on Sonic sounds OK on composite but Space Harrier sounds like it could use a sound upgrade,
Re: Sega Megadrive 2 PCB
The Megafire controller isn't really necessary because Space Harrier II has a selectable rapid-fire option whereas the original version doesn't.
I got an original version working on my console using a Master system to Megadrive adapter and the Megafire is useful with it, the rapid-fire option with Space Harrier II isn't quite the same as a Megafire, but it works well enough.
I got an original version working on my console using a Master system to Megadrive adapter and the Megafire is useful with it, the rapid-fire option with Space Harrier II isn't quite the same as a Megafire, but it works well enough.