Jump to content

Forums

  1. Important Information

    1. The 68kMLA Forum Rules   (10113 visits to this link)

      To quote vintage Apple manuals: "Read Me First!"

  2. Community Connections

    1. General 68kMLA News & Stuff

      What's going down in the barracks.

      3972
      posts
    2. Conquests

      Discuss your latest vintage Mac finds!

      39539
      posts
    3. Trading Post

      Feel free to trade all of your Mac goodies here with all honest intentions. The website provider assumes NO liability, so buyer beware! Please see this topic for more information.

      53041
      posts
  3. Projects & Hosted Forums

    1. RetroChallenge

      What can you do given only one month and strictly "retro" hardware? Find out with RetroChallenge!
      http://retrochallenge.org/

      1486
      posts
    2. 68kMLA Wiki

      The creation and maintenance of the 68kMLA's information repository.
      http://68kmla.org/wiki/

      498
      posts
  4. 68k Model Forums

    1. Compact Mac

      Macintosh, 512k, SE, etc.

      45918
      posts
    2. Mac II, Quadra & Centris

      Just think, having a Quadra 950 in 1992 would be like having a Mac Pro today… except with more slots, more expandability, and on-board SCSI!

      13052
      posts
    3. 68k LC & Performa

      Ah, the consumer computers!

      7955
      posts
    4. 68k PowerBook

      From the Portable to the 190cs.

      9864
      posts
  5. PowerPC Model Forums

    1. NuBus Power Mac, LC & Performa

      The NuBus architecture gets a new brain!

      2672
      posts
    2. PCI Power Mac & Performa

      The PPC comes of age and adopts the industry standard expansion slot.

      5881
      posts
    3. G3/G4/G5 Power Mac, iMac & eMac

      From the Beige G3 to the quad-core G5, via various iMacs!

      13730
      posts
    4. PPC PowerBook & iBook

      All that power in a laptop? Never…

      8965
      posts
  6. Everything Else…

    1. Apple I, ][, /// & Lisa

      Not really 68k Macs, but certainly Vintage!

      7392
      posts
    2. Newton

      The best PDA ever finally gets its own forum!

      1066
      posts
    3. Software

      Includes system stuff, productivity, emulation, design, and games for pre-OS X Macs!

      17461
      posts
    4. Hacks & Development

      Yes, it's back! Hardware hacks/modifications and software development for Mac OS.

      18564
      posts
    5. Peripherals

      Anything you can hook up to your Mac or stuff into it as an interface!

      14539
      posts
  • 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
×