Z-RAM-3D ram upgrage module.

[fatwizard]

Hi all,  I bought a pig in a poke on eBay the other day.  It's a RAM upgrade board that was removed form a "working" ST.  It's called a "Z-RAM-3d/4Meg." by a company called Zubair Interfaces Inc.  There was no documentation with this item, but I also bought the motherboard the upgrade was originally installed on.  The motherboard had been scrapped out.  The socketed chips were removed and the RAM looks like it was removed with a chisel, but the attachment points for the ram upgrade were visible.  The problem is there are more connections coming from the upgrade module than there are attachment points on the motherboard.

 

So my hope is that someone here has, or has documentation, or really any information on this ram upgrade.

[snarkdluG]

If you remove the Shifter chip (large chip in the middle) what does it say on the board? If its for a Mega 2 then all the wires should attach to another board which fit over the MMU. So the ram upgrade has been modified for a ST instead.

 

Look here: https://docs.dev-docs.org/htm/search.php?find=Z-RAM

[fatwizard]

There is nothing printed on the board under the shifter chip, but I suspect you are right about this.  I had actually found the document referenced, and I believe there are pieces missing.  Too bad.

[CommodoreDecker]

I just bought one a couple months ago.  The gaggle of wires leads to a smaller circuit board, which appears to fit atop the MMU...  Am including photos.  I'm trying to find suitable RAM, all the same model and speed... is it possible to mix speeds (eg. 511000 chips at 100ns and 70ns?)   I've also seen 511000 and 511001 chips and am trying to find if both are of the same 1mbit standard and compatible...

  

 

 

 

Edited November 5, 2023 by CommodoreDecker