Recently scored a 512k logic board on eBay and it came with a "Relax" upgrade. I presume it's some sort of CPU or RAM upgrade but I couldn't find anything online. Anyone have any info?
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Macintosh 512k Logic Board w/ Relax Upgrade
- Thread starter retrotech42
- Start date
I can't really make out the markings on that large chip, but it looks to me like a SCSI upgrade daughter card. Plus that ribbon cable should have a DB-25 port at the end, doesn't it?
It's too small to be an 680x0 in a DIP package and it's slightly too large to be anything 8 bit (and that can't be it either because A/No such thing existed before the IIe emulation card for the LC PDS and B/There are only two chips on the PCB, an accelerator usually needs more and a couple of capacitors as well)
All that being said, those upgrade cards (whatever they may be) are really nice. Great find!
More pics, please!
It's too small to be an 680x0 in a DIP package and it's slightly too large to be anything 8 bit (and that can't be it either because A/No such thing existed before the IIe emulation card for the LC PDS and B/There are only two chips on the PCB, an accelerator usually needs more and a couple of capacitors as well)
All that being said, those upgrade cards (whatever they may be) are really nice. Great find!
More pics, please!
512K + SCSI2SD = innerspace Nirvana
Interesting, got a thread about it with pics?
I've got the pics I took of the thing in my thread when I took the motherboard out.
http://i.imgur.com/RXPAc5x.jpg
http://i.imgur.com/wvkkN8x.jpg
http://i.imgur.com/n7sUeXS.jpg
It's got 4MB of RAM on it and both a mystery pin header near the rear and another mystery pin header on the edge of the board. I also haven't successfully been able to turn the 68020 and FPU on, but perhaps I need a dedicated hard drive for that.
http://i.imgur.com/RXPAc5x.jpg
http://i.imgur.com/wvkkN8x.jpg
http://i.imgur.com/n7sUeXS.jpg
It's got 4MB of RAM on it and both a mystery pin header near the rear and another mystery pin header on the edge of the board. I also haven't successfully been able to turn the 68020 and FPU on, but perhaps I need a dedicated hard drive for that.
Good to know! I'll be sure to post more detailed pictures once I get the board. The seller didn't take pictures of the ribbon cable, but I'll assume that's its DB-25. Regarding the Mac Plus ROMs, would I need to just solder them where the empty slots are?
The large header probably is there for connecting a graphics card. I have got a similar upgrade in my SE that has the same header.
Looks like t's plugged into the ROM sockets and gets eight additional lines off the CPU.
I honestly can't tell if it's soldered to the CPU or connected some other way. There's some mysterious pins (I call them "jail bars") connecting the board to the 512k main board underneath but I haven't tried to take the thing apart because I'm worried about ruining both a rare accelerator and a pristine 512k motherboard.
