Image Map Image Map

Search:

Type: Posts; User: iz8dwf

Page 1 of 20 1 2 3 4

Search: Search took 0.28 seconds.

  1. Replies
    4
    Views
    105

    I think you mean 2049 ($0801). What command are...

    I think you mean 2049 ($0801). What command are you using to load the HILOADER?

    Frank
  2. Replies
    40
    Views
    2,238

    https://github.com/sjgray/cbm-edit-rom and...

    https://github.com/sjgray/cbm-edit-rom

    and more generally here:

    http://www.6502.org/users/sjgray/projects/editrom/
  3. Replies
    40
    Views
    2,238

    That's a well known adapter, the design is around...

    That's a well known adapter, the design is around 30 years old or more now :) However, the older PETs (no-CRTC, 9 inch monitor) have different sync frequencies and can be easily displayed on an old...
  4. Replies
    40
    Views
    2,238

    to me, Hsync doesn't seem to be correct, maybe...

    to me, Hsync doesn't seem to be correct, maybe also Vsync. How did you adapt the peculiar scan rates of a CRTC PET to that monitor? I use an old MDA monitor with a little board adapter to display...
  5. Replies
    7
    Views
    388

    some, not all. ...

    some, not all.

    http://www.zimmers.net/anonftp/pub/cbm/schematics/datassette/cas-10r.gif
  6. Replies
    7
    Views
    388

    afair it's not a pass through connector, it's a...

    afair it's not a pass through connector, it's a test port to access various signals. My memory could fail after more than 30 years though.
    Frank
  7. Replies
    11
    Views
    371

    Voltages are too low and it's strange that all...

    Voltages are too low and it's strange that all are too low at once. Did you check your voltmeter with a known good reference or another good board with +5V supply for example?
    Do the regulators get...
  8. Thread: NTSC in Europe.

    by iz8dwf
    Replies
    11
    Views
    581

    Exactly, since at least 20 years, all TVs (even...

    Exactly, since at least 20 years, all TVs (even the old CRT ones) have multistandard inputs and can display NTSC signals just fine. Even my old analog TV USB receiver is completely multi-standard.
    I...
  9. Replies
    9
    Views
    604

    Unreliable is never an opinion. Most of us know...

    Unreliable is never an opinion.
    Most of us know that MOS technology produced some unreliable ICs, since a large part of them failed in computers where all the rest of logic chips (not produced by...
  10. Replies
    9
    Views
    604

    Experience is experience. It might not be...

    Experience is experience. It might not be statistically "large enough", but it's still valid as "single data points in statistics".
    I still don't believe that calling the 4116 "unreliable" is...
  11. Replies
    9
    Views
    604

    Apple //e wikipedia page

    Hi all,
    I'm not exactly an Apple expert, but I surely have a long enough record of repairs (starting in the middle 1980s).
    Now, the Apple //e wikipedia page:
    ...
  12. anode grid collapsed can make bad distortion on...

    anode grid collapsed can make bad distortion on all or parts of a CRT. Sometimes also the focusing grid can. I've seen a few cases in the last 30 years.
    I agree however that it's more likely the...
  13. It is the contrary: if the image turns with the...

    It is the contrary: if the image turns with the yoke, it's a damaged yoke, if the image doesn't turn with the yoke, it's a bad CRT.

    Frank
  14. Precisely. And I've seen bad CRTs in a couple of...

    Precisely.
    And I've seen bad CRTs in a couple of occasion (on two different oscilloscopes though, not monitors) that would produce a badly distorted image, more likely because of distorted/damaged...
  15. If the problem is in the vertical coils, they're...

    If the problem is in the vertical coils, they're also easy enough to be rewound even by hand, they are the external ones. I'd try rotating the yoke 90 degrees to see if the symptoms rotates also by...
  16. Replies
    9
    Views
    476

    And also, MOS/CSG never succeeded in making...

    And also, MOS/CSG never succeeded in making working DRAMs.

    Frank
  17. Replies
    31
    Views
    1,297

    When I had to change C51 (because the tantalum...

    When I had to change C51 (because the tantalum failed short-circuit), I always opted for a 1uF ceramic as replacement. I think a regular aluminum electrolytic should work there unless it's really of...
  18. Replies
    31
    Views
    1,297

    smells like damaged PCB tracks and/or hole...

    smells like damaged PCB tracks and/or hole metallization damaged making no contact to GND on pin 1 of the 555 and/or surrounding capacitors.
    Solder iron is the worst enemy of any vintage repair.
    ...
  19. Replies
    30
    Views
    1,157

    Unlike any other ROM/EPROM I can think of,...

    Unlike any other ROM/EPROM I can think of, MK36000 have "edge activated" /CE. It means you can't read such a ROM by simply pulling /CE low and cycling through the addresses, waiting for the access...
  20. Replies
    3
    Views
    242

    With a logic probe, you would first check the...

    With a logic probe, you would first check the clock output from the VIC to the CPU, then check the reset signal to the CPU, then check all the enables on the ROMs and that would tell you if and how...
  21. Replies
    15
    Views
    1,049

    Thanks :) I was feeling so bad for those C64 @...

    Thanks :) I was feeling so bad for those C64 @ 14V :)
    Frank
  22. Replies
    15
    Views
    1,049

    I wonder why 14V AC. The original C64/C128 PSUs...

    I wonder why 14V AC. The original C64/C128 PSUs have 9VAC output, usually it's around 10-11V max. All the C64 "breadbin" boards have an additional LM7805 linear voltage regulator, feed by the 9VAC...
  23. Thread: 8032 CRT issue

    by iz8dwf
    Replies
    26
    Views
    1,452

    Have you checked the rectifier diodes in the...

    Have you checked the rectifier diodes in the monitor's PCB? The big smoothing capacitor? The 18V linear regulator?
    These are absolutely the first steps in any kind of repair job.

    Frank
  24. Replies
    10
    Views
    927

    Yes I've found out the documentation for my 2 x...

    Yes I've found out the documentation for my 2 x 80col/64k expansions, they're really only meant for the IIe "special" slot 3.
    Does anyone want to swap? :)
    I can also make my own cards, I just need...
  25. Replies
    2
    Views
    461

    Thanks a LOT!! I downloaded the disk image!

    Thanks a LOT!! I downloaded the disk image!
Results 1 to 25 of 500
Page 1 of 20 1 2 3 4