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Recent content by VeryVon

  1. VeryVon

    Avatar / profile picture

    Yes, profile picture is locked for new users.
  2. VeryVon

    File Read Error on C128 floppy disks

    Also, check the surface of the disk for mold.
  3. VeryVon

    Anyone recognise this Philips 5 1/4 floppy drive ?

    Agreed. After a bit of searching through PDF's I couldn't locate a schematic, but maybe more digging will reveal it.
  4. VeryVon

    Anyone recognise this Philips 5 1/4 floppy drive ?

    The only thing I could find was this page in german: https://forum.classic-computing.de/forum/index.php?thread/14546-kennt-jemand-einen-rechner-namens-philips-p2500/&postID=192423#post192423
  5. VeryVon

    Five Festive 5150 Boards (BOARD #4 Thread)

    Welcome to Board #4! [Link to Original Thread / Board #3] Initially the address on the ISA slot wasn't reading correctly during ground I/O CH RDY procedure (simiar to Board #1) and as in Board #1 the address bus chips (U7 / U9 / U10) were not enabled. I took a look at U98 & U67. As in Board...
  6. VeryVon

    Five Festive 5150 Boards (BOARD #1 Thread)

    Has some fun programming in NASM, displaying bits & test patterns etc (the RDR asm is so well documented, it's practically a tutorial / clinic on how to write code) and I'm going to move on to the final board. Might come back to this one.
  7. VeryVon

    Wipe admin password in XP but only via floppy?

    Did you also try the usual password suspects? Blank password, "password", "secret", "123456", etc.
  8. VeryVon

    Five Festive 5150 Boards (BOARD #1 Thread)

    Sounds like something powered by AI :) Good point, easy to do and worth a try Will do. I'm leaning towards putting a socket on that chip just to try another and rule out that it's glitching as those so often do fail p.s. using interrupts is there a way to arrange single-stepping the CPU one...
  9. VeryVon

    Five Festive 5150 Boards (BOARD #1 Thread)

    Ok yea, nevermind. I created a version of the ROM that loops testing the first byte of memory, but I don't think its stable enough to get a read of what's going on before it crashes.
  10. VeryVon

    Five Festive 5150 Boards (BOARD #1 Thread)

    On a side note I have RDR running in pce-ibmpc to test some code modifications.
  11. VeryVon

    Five Festive 5150 Boards (BOARD #1 Thread)

    I know what you mean. Let me expand a little bit on the test. Sometimes RDR doesn't crash, and reports a failure. The test code would simply test RAM address 0000:0000 in a loop. I guess the question is would the loop crash the board. I don't know. If the board doesn't crash testing...
  12. VeryVon

    Five Festive 5150 Boards (BOARD #1 Thread)

    Sounds good. Glad you have some more ideas because pulled U13, U15 & U16 tonight. They check out ok as far as I can tell. To check the signals on all these IC's, do you think it's worth trying to develop a custom ROM to reproduce the issue? Something I could run on a working board, and...
  13. VeryVon

    Five Festive 5150 Boards (BOARD #1 Thread)

    I created a new RDR ROM, but RAM tests and crashing persist CPU to ROM would be U15 / U16, and ROM to CPU would be U13 correct? If that's the case i'm going to start pulling and replacing those chips one at a time. Seems like 1/3 of the chips on this board are fried anyway :LOL:
  14. VeryVon

    Five Festive 5150 Boards (BOARD #1 Thread)

    I thought U12 might be the issue, but after setting up a capture with the LA, it looks fine. Out of ideas at the moment. Board is unstable, 1 out of 3 RDR runs the board crashes at the first 2KB RAM test. Largest address failure I've seen is b.
  15. VeryVon

    Five Festive 5150 Boards (BOARD #1 Thread)

    Replaced U101 and now all RDR 8253 timer channel tests pass. On to the RAM now. I'm a bit surprised the first 2 KB of RAM always fails after TEST5060 & TEST5067 passed on the LA. Sometimes it crashes RDR as well.
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