Amiga 3000 ZIPs DRAM solution ?

[Zac67]

The easy solution: buy ZIPs at ebay, Softhut, ...

The cheap solution with a moderate amount of work: build a PS/2 SIMM adapter that fits on top of the ZIP sockets and load that with 4/8 MB SIMMs. The PCB & sockets are <$10, SIMMs are free and work ~1 day. With an A3640 CPU board there's no sense fitting static column chips as it can't burst anyway.

The adapters you were looking at will most likely not fit, as countzero pointed out. The amount of work is ridiculous and the material still pricey.

[Zac67]

The SOJ chips are already a bit thicker than ZIPs. According to the data sheet, the adapter adds 1.27 mm to that and I highly doubt that they do fit - although I'd have to measure the spacing to be sure.

Of course you have to know, which line is where:

[Zac67]

Oh btw: if you can't get a hold on PS/2 SIMM sockets: just solder short pieces of wire to the contacts and use them as SIPs - quickly done and works great.

[Zac67]

@eslapion
Take a look at the schematics: there are four CAS and four RAS lines to address the four RAM banks (1 MB or 4 MB each). With PS/2 SIMMs you can either use 4 sockets (one bank each/4 MB SIMMs) or 2 sockets (two banks each/8 MB SIMMs). The latter are even more common and need less soldering.

I think the DIP sockets will only take 256x4 chips, so you're stuck with 256x4 ZIPs, too. No point having 4 MB total.
Are you sure those take 1Mx4, too?

[Zac67]

Looking at the pinout, you're completely right - didn't know that yet!

I'm still looking for 8pcs 1Mx4 static column (514402) - just to replace the one bank FP for completeness. ;-)