SGI O2 128MB DRAM module
New 128MB RAM modules for the SGI O2. Designed with currently in production off the shelf parts, so no need to source obsolete components.
Attached below SGI_O2_DRAM_128MB_A00_RELEASE.zip archive.
1.SCH_BRD – contains editable schematic and board file. Format is Eagle CAD, but they can be imported in other tools, like Kicad.
2.SCH_PDF- schematic in pdf format.
3.P&P – pick and place files
4.BOM
5.GERBER – gerber files
6.JLC – contains all the needed files for a production run at JLCPCB. Just upload the GERBER zip file, BOM file and CPL file. They currently have everything in stock except CDCVF2510APW and SN74ALVCH16721DGG. These can be found at Mouser/Digikey etc.
Important PCB specs:
-thickness 1.2mm
-finish: ENIG
-gold fingers (beveling not needed)
-stackup (for JLC) JLC06121H-3313A (ideally) or JLC06121H-3313.
The exact RAM part number I used is IS42S16400N-7TL, but one could also use:
IS42S16400N-6TL
IS42S16400N-6TLI
IS42S16400N-7TLI
IS42S16400J-6TL
IS42S16400J-6TLI
IS42S16400J-7TL
IS42S16400J-7TLI
Other RAM ICs could be used instead, as long as they’re organized as 1M x 16bits x 4 banks (64Mb) and are in a 54-pin TSOP II package. Speed rating doesn’t really matter as the O2 runs the memory at 66MHz.
Love that!
Greetings from Poland!
Greetings from Romania!
you have the same for octanes?
Not yet, I only have an O2.
Oh my god! If you could make it for octane it would be a complete absolute fantasy! So much hope after seeing this page!
All the best to you!
I have a few more things planned for the O2, after that I’ll get an Octane or Indy, so there’s a high change of making RAM modules for Octane.
All the best to you as well!
This is simply amazing stuff, thank you for sharing! One thing that would be fantastic is if you were to try and reverse-engineer the CPU boards used on the O2 (mainly the R5k ones). No doubt you’ve seen the past mods for upgrading the O2 CPU to the 600MHz R7k option in the past. I believe one of the reasons these were challenging is that they required sacrificing an existing R5k 300MHz board and replacing the PROM – obviously risky when SGI stuff is harder to come by these days. If such a module could be made from scratch with new components, that would be an incredible upgrade option for O2s in general.
I will be making a new CPU module, with some interesting upgrades.
However, it’s more of a one off thing. Such a module can’t be made from scratch with new components because:
-VICE IC is needed. Only source is another CPU module.
-CACHE ICs are basically impossible to find
-RM7000C CPUs are also pretty hard to find, I already got scammed with remarked ICs.