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  • Posts

    • Actually, the Quadra 610 and 650 did have a pretty hard 136 MB limit on RAM, even when larger modules were installed, until bbraun (or was it Doug, darn, now it's been too long) dug into the firmware a bit and changed some boot parameters so that the memory controller was allowed to "see" more memory.   There was a thread on it around here before the system change.  I hope its still around.   IIRC, he took the 650/800 up to 512MB or thereabouts.  Part of that may have been forced into a RAM Disk.    On the SE/30, each bank of four 30 pin SIMMs is the equivalent of one, single bank, 72 pin SIMM.    If you built the machine with two 72 pin SIMM sockets, they'd be limited to 16MB or 64MB SIMMs.     32 MB 72 pin SIMMs are not going to work in such an adaptation, because almost all the 32 MB SIMMs in existence are 2 bank SIMMs.  They're made out of two separate banks of 16 MB.  Banks are controlled by having independently controlled RAS lines.  There's no reason to believe that the there are any more than two sets of RAS lines in SE/30.     One possibility would be to modify the board for a single 72 pin socket.  Combine the signals for the two SE/30 memory banks onto a single 72 pin Socket, which would support one or two banks.    That way, one could install a single 16, 32, 64 or 128 MB SIMM and it would work.   If you go with two sockets, then the only way to get 128MB would be with two separate 64MB SIMMs and again, 32 MB SIMMs would not work, or would only be seen as 16 MB.
    • I replied without reading it carefully, but what you are talking about is adjustment in York.
      And in the case of my CRT, the convergence went awry, so I couldn't adjust the yoke unless I turned it about 180 degrees. You can see that the convergence is out of order in the previous images...Convergence is now adjusted.
      I was mistaken for the variable width range. But thx for advice!
    • Also bumping the inner/outer copper on the board might help get a better fit. 
    • Well my first ones were 1.6mm, but they are WAYYY too hard to get in/out of the socket. I basically had to wriggle it back and forth multiple times for it to fit in the socket and getting it out felt like I was going to rip the whole board with it. I measured the original ram I have here and it's around 1.2mm, but if it needs to be a little bigger, then I'll do some tricks I guess heh. 
    • I made a two layer version out of the schematics that fly around on the interwebs because cheap:   Couldn't get them to work reliably yet because of the whole PCB thickness thing. If you wiggle them around before use and put on rubber bands they are ok for a while.   What thickness did you choose for yours? I ordered some in 1.6mm as well as 1.2mm from JLCPCB. 1.6mm is really tough to get into the socket and 1.2mm is more on the floppy side of things.     IIfxRAM_2Layer.brd IIfxRAM_2Layer.sch