Recent content by David Cook

  1. David Cook

    68k Determining amount of installed RAM

    If you want to be compatible with Apple's Switcher, don't forget to check it's low memory global before calling MFTopMem. Otherwise you'll crash (?) or get the wrong value. See Technical Note #158. That is so funny. I've been updating my Tiny Transfer program and cringing as I consume an...
  2. David Cook

    68k Determining amount of installed RAM

    Looks good. BTW: Gestalt in often implemented in compiler glue to provide basic services when the OS doesn't actually have Gestalt. Not sure whether Think C 4 provides that or not. For example, Apple provided this code, which (you'll be happy to see) mimics what you have already implemented...
  3. David Cook

    Macintosh LC 475-recap PSU Dyna Comp DCF 353 (apple part No-614-0028}

    I reuse parts across different models that I repair. Therefore, my capacitor list may not be optimized for this power supply. C19 C20 10x20 1000uf 10v 5mm ls A750MV108M1EAAE014 C18 13x25 2200uF 10v 5mm ls A750MW228M1CAAE010 C15 10x20 330uF 35v 5mm A750KW337M1VAAE020 C16, C21, C22 6.5x15 82uF...
  4. David Cook

    68k Any sampling profilers for Mac 68k?

    Hold the phone! What is this? https://github.com/laniku/sys71src/blob/main/Interfaces/CIncludes/Perf.h Did Apple already create a performance library? You may just need to call this and then convert the report file into routine names via the debug data file.
  5. David Cook

    68k Any sampling profilers for Mac 68k?

    BTW, it looks like Apple's Time Manager source code is available. It might help you understand what the stack (and registers) should like like when your routine is called. The exact Time Manager code will depend on your ROM / System. But, this might help...
  6. David Cook

    68k Any sampling profilers for Mac 68k?

    Here's a possible approach. 1. Run a test program that shows an alert with it's address range when it starts up. Then have it do some heavy looping with occasional calls to WaitNextEvent/GetNextEvent. 2. Add a debug breakpoint in your Time Manager program. 3. Each time it breaks, dump the stack...
  7. David Cook

    IIsi w/ROM - repair and photos

    OMG. Your damage was far worse. I would not have even attempted your floppy restoration. Congrats on saving another Mac!
  8. David Cook

    IIsi w/ROM - repair and photos

    Macintosh IIsi computers don't sell for as much as other Macs from the time period. IIsis tend to have motherboard capacitor damage and the power supplies must be recapped urgently. They have medium speed, one slot, and built-in video, so they are sweet little machines if you get them working...
  9. David Cook

    SuperMac Supermatch 17 monitor missing pins

    That's great news! Happy to help. I'm glad you are keeping the SuperMac monitor. They aren't making any new ones. : )
  10. David Cook

    SuperMac Supermatch 17 monitor missing pins

    Here are photos of the SuperMac adapters that I presume they made to allow their monitors to work with internal video: DB-15 female on one end. DB-15 male on the other end. They pass the video signals straight through but contain the sense wires inside the adapter itself. Part...
  11. David Cook

    SuperMac Supermatch 17 monitor missing pins

    Not necessarily. I just wanted to alert you to that option. In fact, I think a lot of the other card manufacturers also provided methods of selecting resolutions (i.e. via a rotary dip switch) other than via the monitor sense pins. I believe I even have a special cable that SuperMac made to...
  12. David Cook

    SuperMac Supermatch 17 monitor missing pins

    Most of the SuperMac video cards don't require sense lines. Instead, they rotate through a series of resolutions and ask you to press the space bar when you see an image. Then, after booting, you can use their software to pick the exact display settings you desire. The setting is then saved to PRAM.
  13. David Cook

    Software-only OVERCLOCK for LC475, LC575, Quadra 605

    That's very interesting. Originally, my thoughts were just as to whether or not the power supply was becoming strained, and how much extra heat was being dissipated by the total board. But, your comment makes me wonder whether I need to learn more about measuring power at across frequencies. I...
  14. David Cook

    Software-only OVERCLOCK for LC475, LC575, Quadra 605

    🤫 Shhh! He didn't mean that folks. Just a late April fools joke.
  15. David Cook

    Software-only OVERCLOCK for LC475, LC575, Quadra 605

    Has anyone tested current draw and/or voltages on the 5V line at different frequencies? I thought @JDW measured voltage at various frequencies (maybe for Spicy O Clock), but I can't find a video with that information.