What did you do today that no one else did?

Discussion in 'Ham Radio Life' started by W7UUU, Jul 6, 2016.

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  1. N0NC

    N0NC Premium Subscriber QRZ Page

    Deja-vu. I had several S-100 computers back in the day. An Imsai, An Alatir 8800, and a Byte-8 (local place in Mountain Vue California). All gone now, of course.

    73, Chuck
    KD2ACO and N3AWS like this.
  2. KD2ACO

    KD2ACO Platinum Subscriber Platinum Subscriber Life Member QRZ Page

    Well, this case was a super PITA and I'm not talking about the bread.

    The computer would crash with processor board flexing, and I've run into that plenty of times over the years. It's a cracked plate though or failed contact on a 40 year old chip socket. Easy Peasy... except that wasn't it.

    P1020575.JPG P1020579.JPG

    It was still crashing with flexure. Poking with a scope revealed that the WAIT line wasn't pulling up to 5v and sure enough, flexing the resistor pack would make the computer come up.

    P1020581.JPG P1020583.JPG

    Oh well, those Mill Max sockets are good. There were also blown transistors on the I/O board and a few other goodies, but it's all working well now.

    I'm going to plug it into my lathe to make sure it's all OK and then drive it down to Queens, NY and get VP's system up and running.

    Oy Vey, make my day... :p
    VK6APZ, N3AWS, N0TZU and 2 others like this.
  3. AD5HR

    AD5HR Ham Member QRZ Page

    That S100 bus is exactly like those found in early 80s arcade games I've worked with.
    Did you replace the Z-80, or had it already been replaced when you got it?
    Were most of the small discreet parts replaced bypass caps?
    Hard to believe these are now 40+ year old "antiques".
    Keep up the good work, I love following your "projects".
    73, Jon
  4. KD2ACO

    KD2ACO Platinum Subscriber Platinum Subscriber Life Member QRZ Page

    I replaced that Z-80 and the PS caps about 6 years ago. I couldn't figure out the problem with the Cromemco SCC at the time and just left one of my spare cards in there.

    I like the Mill-Max sockets with built-in bypass caps. Getting some of the caps off of the board makes it easier to poke around with a scope when troubleshooting.

    Well, when my spare cards finally died, I just had to spend a couple of days getting all of my spares to work, so now, I'm going to put the original cards back in, etc. and I have about 4 sets of cards. I bought out the Zuma stock from John Bittner about 10 years ago too. He was really tired of fixing his ancient products and I relieved him of several large boxes of parts so he could park his car in the garage. :p He couldn't believe that people were still using them. Now I'm the keeper of the Zuma cutting computers, so I get the calls now.

    I'm glad you like the projects! Most of the stuff I work on is antique but people still need the items to function.

    I'd like to thank Greg @W9GB for his posts to a different Zeddite about the S-100 fan club. That bit of info really was an eye-opener for me! Very helpful.

    Last edited: Sep 12, 2021
    SA1CKE and AD5HR like this.
  5. W9JEF

    W9JEF Platinum Subscriber Platinum Subscriber QRZ Page

    I made an indoor 90° corner reflector antenna for the UHF TV channels in our area.

    Last edited: Sep 16, 2021
    W7TCT, K8PG, UT7UX and 7 others like this.
  6. WF7A

    WF7A Subscriber QRZ Page

    "Honey, I've looked everywhere for my cookie cooling racks and can't find them anywhere!"
    VK6APZ, W7TCT, K8PG and 9 others like this.
  7. NN4RH

    NN4RH Premium Subscriber QRZ Page

    A spring or two on that thing and it'd make a decent squirrel trap.
    W7TCT, W7EDC, AD5HR and 5 others like this.
  8. KD2ACO

    KD2ACO Platinum Subscriber Platinum Subscriber Life Member QRZ Page

    When the TV screen goes blank, you'd know it was time to heat up the stew pot!
    N3AWS, KU4X, W7UUU and 3 others like this.
  9. NN4RH

    NN4RH Premium Subscriber QRZ Page

    Yesterday, actually. I survived the side-effects of the Shingrix vaccine. Haven't been that sick in a long time.
    W9JEF, KD2ACO and N0TZU like this.
  10. W7HV

    W7HV Ham Member QRZ Page

    Funny. I had strong reaction to the first shingrix shot but nothing to the second, which is opposite to what I expected and opposite to my reaction to the the current shots most everybody is getting nowadays. I'll add that though I felt pretty bad, in both cases it was over in less than 24 hrs, so no biggie.

    Back on topic: I have racks like that, and I hate squirrels, so we may be onto something here.
    W9JEF and KD2ACO like this.

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