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Hi Todd,
That's a good idea, bad ram on an old RAM card just compounds the problems and makes fixing these old IMSAI's a big challenge. I am very pleased with my recipe. Take 1 Buffered S100 Proto board, (4) 74LS245's, (1) 7805 and mix. Add in (1) 74LS00 and (2) 51256 (32K SRAM) chips and bake for 30 minutes at 350 degrees. It's all new (or NOS) chips, takes the guess work out of RAM problems. If you like, I can send you a schematic & pictures of my board. What's your email address? PS. I've got a good handle on the IMSAI CPA and CPU cards, so feel free to pick my brains. Cheers, Josh > Date: Mon, 31 Dec 2012 17:39:11 -0600 > From: litte...@mchsi.com > To: n8vem...@googlegroups.com > Subject: Re: [N8VEM-S100:1237] S-100 board reorders > > I'm interested in building a simple 64K RAM board for > the same reason. I have two Imsai's, both with > multiple RAM card(s) with many memory chips. > > If someone could point me to a schematic, I'd > like to build a few. I know Don Caprio mentioned > earlier this year he had a project on the PBworks > page but I don't know where to find it. > > I'd like to look at a few designs. > > Todd > > > ----- Original Message ----- > From: "Crusty OMO" <cru...@hotmail.com> > To: n8vem...@googlegroups.com > Sent: Sunday, December 30, 2012 9:45:54 PM GMT -06:00 Central America > Subject: RE: [N8VEM-S100:1236] S-100 board reorders > > > Hi Andrew, > > Cool, thanks! Just a note on what I'm using the first (buffered) prototyping board for.... > It's currently being used as a 64K RAM card in my IMSAI. This was done to establish a working system. I'll be replacing this RAM card with the old RAM cards when I test/fix them. > At that point, I'll repurpose this card to be an 8080 CPU, RAM & I/O card for another IMSAI system I'd like to resurrect. > > Cheers, > Josh > > > > > |