Image Map Image Map

Search:

Type: Posts; User: Dwight Elvey

Page 1 of 20 1 2 3 4

Search: Search took 0.09 seconds.

  1. I'm glad to see that replacing the regulator...

    I'm glad to see that replacing the regulator brought it back to life. Still, years of experience has taught me to check all the angles before replacing anything. You should only replace electrolytics...
  2. Replies
    23
    Views
    531

    Most of the people that got one of my debug...

    Most of the people that got one of my debug boards and the kit to make a replacement RRIOT, found that after putting together the debug board, the source of the errors was more mundane than the RRIOT...
  3. It looks like a nice collection of boards. I see...

    It looks like a nice collection of boards. I see a terminator boards as well. The $950 one has the older power supply but it looks to have the upgraded power supply.
    Dwight
  4. There are a lot of instructions that will work as...

    There are a lot of instructions that will work as good as a NOP. It just needs to be a single machine cycle operation. Most all of the register to register ALU operations are single cycle. That fact...
  5. Power rail always have capacitors on them. These...

    Power rail always have capacitors on them. These can be shorted. Since you have a voltmeter, I'm sure it can read ohms. With the power turned off, measure the resistance from the output of the...
  6. Replies
    31
    Views
    572

    Notice the words, "I've been doing that for...

    Notice the words, "I've been doing that for years". Most likely over and over and over.
    I wish there was something one could use on the silver coated mica used in the miniature IF filters. The...
  7. Of course, smaller. I suspect they are out there...

    Of course, smaller. I suspect they are out there someplace. I know some PCs used a similar connector for external drives but I don't know it is was smaller or larger spacing.
    Dwight
  8. I forget what the connectors are called but this...

    I forget what the connectors are called but this looks to be the same style as we often call a centronics printer connector. look through a digikey calalog and you should find something similar....
  9. Replies
    31
    Views
    572

    Years ago, I did some experiments. While at...

    Years ago, I did some experiments. While at Intel, I was often reseating things. In some cases, we found that things like using an orange eraser would actually cause later corrosion. It was from the...
  10. Replies
    46
    Views
    1,082

    Which side the cap goes on is usually not...

    Which side the cap goes on is usually not important. There is a slight difference in the low pass as the wipper of the pot is moved from one end to the other, if the capacitor is on the output side...
  11. I gave it a little more thought, read a few...

    I gave it a little more thought, read a few comments and all seem to be assuming it was an integer number issue. It could have just as likely been a floating point number. Floating point numbers have...
  12. Replies
    4
    Views
    136

    It is clearly not a printer interface. 7485s are...

    It is clearly not a printer interface. 7485s are magnitude comparitors. There are 8 of them and each compares 4 bits. That would be 32 bits. There doesn't look to be enough wires to send 32 bits from...
  13. Both integer and floating point numbers have...

    Both integer and floating point numbers have their limits in such application. A case in point was using a floating point time accumulator. It needed to be fast, something in the us to ms range....
  14. His application expects an octal stream, not...

    His application expects an octal stream, not binary or S format or Intel Hex.
    One could make a "blue pill" be a translator. It would be trivial code but would require a little circuit to take the...
  15. Replies
    23
    Views
    531

    A friend and I were sent to LA for something, I...

    A friend and I were sent to LA for something, I forget what. We stopped at a surplus place. They had about 100 early PETs. I forget which model. They were $30 each. I wasn't interested at the time....
  16. Replies
    46
    Views
    1,082

    He still might add a capacitor. Something like a...

    He still might add a capacitor. Something like a ceramic disk of about 1uF should be fine.
    Dwight
  17. To understand what might be the problem, you have...

    To understand what might be the problem, you have to first understand how the front panel works.
    First, there is likely nothing wrong with the address bus.
    You have something wrong with the examine...
  18. Replies
    15
    Views
    306

    I think with the design as shown, A9 and A10...

    I think with the design as shown, A9 and A10 would have allowed interrupts without issues.
    Dwight
  19. Replies
    15
    Views
    306

    One wonders why this address range was chosen?...

    One wonders why this address range was chosen? Was there another purpose?
    Dwight
  20. I should also mention that is is not likely the...

    I should also mention that is is not likely the transformer that is the problem. This is because the two higher voltages look good. The transformer is usually wired such that these higher voltages...
  21. Replies
    15
    Views
    306

    So it seems that a page 0 access can make about a...

    So it seems that a page 0 access can make about a 2% or better adjustment of the frequency.
    Dwight
  22. Replies
    15
    Views
    306

    I wonder how the latch is wired up on the 300....

    I wonder how the latch is wired up on the 300. Will accessing page zero effect it. If not, there are a number of page zero operations that can be used to fine tune, closer than a NOP. The page zero...
  23. Bad diodes will usually show up as 60Hz ripple...

    Bad diodes will usually show up as 60Hz ripple while a bad capacitor will be 120Hz ripple. You need a scope to see this.
    Dwight
  24. Replies
    8
    Views
    257

    Even though, I prefer Anchor, the one on 7th...

    Even though, I prefer Anchor, the one on 7th should be visited, as well. It is a large warehouse. You could spend an hour there looking through things. It is on the South-West corner of 7th and Alma....
  25. Replies
    8
    Views
    257

    I went to ExcessSolutions and found that they...

    I went to ExcessSolutions and found that they were not interested in selling wire by the foot. I did not try to find and thing like ICs but did walk around. I got the feeling that they were not that...
Results 1 to 25 of 500
Page 1 of 20 1 2 3 4