Image Map Image Map

Search:

Type: Posts; User: Witchy

Page 1 of 12 1 2 3 4

Search: Search took 0.01 seconds.

  1. Replies
    5
    Views
    419

    Ah ok, yes, my measuring was from the transformer...

    Ah ok, yes, my measuring was from the transformer to the common 0V rail at the output, so the reason I don't get a short on the -12V rail too is because there's a resistor in the way whereas +5/+12...
  2. Replies
    5
    Views
    419

    Update on this. With a bulb on the 12V line I...

    Update on this. With a bulb on the 12V line I still got nothing so I pulled all the electrolytics apart from the weird 4-terminal 100uF inrush cap (if that's the right name for it) and they all...
  3. Replies
    7
    Views
    854

    That's what both he and I remember but I agree on...

    That's what both he and I remember but I agree on not fully dismantling. I'll pass that on, cheers![/COLOR]
  4. Replies
    7
    Views
    854

    Dismantle an RL02 pack

    Hi folks,

    An old DEC-related colleague of mine is trying to revive an RL02 drive with some packs and is starting with a thorough cleaning. BITD we had a company come round with a proper pack...
  5. Replies
    5
    Views
    419

    Ah ok, so just coincidence then I hope, given the...

    Ah ok, so just coincidence then I hope, given the age of all the components. The reason I suspected a short was because the damage to the 1488 is at pin 12 which is the CS0 line of the ACIA at U7 as...
  6. Replies
    5
    Views
    419

    CBM-II/B700 PSU fail

    Hi folks,

    Recently I dug out my B700 high profile, UK edition, and predictably it seemed dead. Probing with a 'scope showed activity though, and the CURSOR pin of the CRTC gave a trace of a...
  7. Another 3-and-a-bit hours' work and it's up and...

    Another 3-and-a-bit hours' work and it's up and running again :D

    First pic is what happens when you accidentally ground the 9V line. Fortunately it cleaned up OK. 2nd pic is first power up with...
  8. OK, embarrassed face time :oops: While...

    OK, embarrassed face time :oops:

    While searching for 'why did my cassette circuitry go up in smoke' I found a post from JonB back in 2016 which I was part of but never saw the last page. There he...
  9. Early start today because I'm at home doing an...

    Early start today because I'm at home doing an HPE course so during breaks I get to keep working on the 4032, excellent. First problem discovered in the cassette circuits. First off I hooked up my...
  10. Well that was a good evening's work thanks to...

    Well that was a good evening's work thanks to both you and Frank! PET is alive again and running without the ROM/RAM board for the first time :D

    Only on 16K though, Frank, is that the official...
  11. I'm already running Dave's PETTEST V4, that's...

    I'm already running Dave's PETTEST V4, that's what's produced the third pic in my previous post showing bad RAM everywhere, pretty much :) I'm now going through the schematic to look at likely...
  12. If you look at how R10 and R11 were when I first...

    If you look at how R10 and R11 were when I first looked at the board at the weekend (first pic) I'd guess someone already did that and couldn't be bothered to put things back together properly. This...
  13. First PET post of October. 4032 with dead RAM subsystem

    Hi folks,

    Long time no post, life and non-PET projects got in the way. I'm slimming down my PET collection because nobody needs 12 and I'm moving house, and was just going to list them on e*ay as...
  14. Replies
    9
    Views
    1,216

    It didn't, if you read further back you'll see...

    It didn't, if you read further back you'll see that Larry spotted my image was one byte too long because I'd missed that one of the flags was two bytes not one. I got it working after that and posted...
  15. Replies
    63
    Views
    4,190

    Apologies folks, I haven't forgotten about this,...

    Apologies folks, I haven't forgotten about this, I've been sorting exhibits for a Japanese Festival this coming weekend and helping a very kind volunteer map out a replacement PCB so he can practice...
  16. Replies
    49
    Views
    6,657

    No problem! It's excellent to see them go to a...

    No problem! It's excellent to see them go to a good home :D [/COLOR]
  17. Replies
    49
    Views
    6,657

    It's nice to see everything's hanging together...

    It's nice to see everything's hanging together nicely!
  18. Replies
    63
    Views
    4,190

    My hookup, er, hooks arrived so I have an...

    My hookup, er, hooks arrived so I have an old-skool means of connecting up the arduino to try and sample what's going on. Happily I was chatting to the designer again today and he's asked for our...
  19. Replies
    63
    Views
    4,190

    Unfortunately you do, kind of. That big stack...

    Unfortunately you do, kind of. That big stack o'wires running up the centre of the schematic is the Emulator that controls all the I/O:

    52929

    The microcontroller at the heart of the emulator...
  20. Replies
    63
    Views
    4,190

    It's an NEC V20 so what's that, 8088? The machine...

    It's an NEC V20 so what's that, 8088? The machine actually runs a rewritten Unix V6 from ROM and the more I've learnt about it the more I've realised how complex it is. I've been talking to the...
  21. Replies
    63
    Views
    4,190

    I do have a complete ROM dump of my machine but...

    I do have a complete ROM dump of my machine but the trouble is the keyboard, RS232 et al are controlled by an external board called the Minerva Emulator, and while I have a dump for the boot ROM for...
  22. Replies
    63
    Views
    4,190

    If there's one thing I love about this hobby it's...

    If there's one thing I love about this hobby it's that things are always way more complicated than I think, I'm grateful to you and Chuck and the others I talk to in the process of bringing things...
  23. Replies
    63
    Views
    4,190

    I don't think it's as complicated as that, but...

    I don't think it's as complicated as that, but yes, hence my thought of just wiring in SK6 and SK7 to 24 ports of the Arduino MEGA256 I bought for this project initially (or finding one that's less...
  24. Replies
    63
    Views
    4,190

    It gets better, I suddenly realised I hadn't...

    It gets better, I suddenly realised I hadn't accounted for modifier keys so I added left shift and right shift to my little protoboard keyboard to see what they did with the analyser. I could've...
  25. Replies
    63
    Views
    4,190

    Sigh, so much for me thinking I could ignore Z5....

    Sigh, so much for me thinking I could ignore Z5. Writing out the lookup table I realised 6 bytes isn't enough for all the keys so I now need to detect the inhibit pin for Z4/Z5 and act accordingly.
    ...
Results 1 to 25 of 294
Page 1 of 12 1 2 3 4