Image Map Image Map
Tab Content
  • falter's Avatar
    Yesterday, 08:57 PM
    falter replied to a thread Poly 88 case in S-100
    So the switch itself works, but the resistor its attached to seems to stay high no matter which position it was in. For an experiment, I tied the...
    277 replies | 12137 view(s)
  • falter's Avatar
    Yesterday, 08:27 PM
    falter replied to a thread Poly 88 case in S-100
    Interesting. Probed with my logic probe all the memory address switches. When they are switched to the ON position, the side of the resistor...
    277 replies | 12137 view(s)
  • falter's Avatar
    Yesterday, 08:12 PM
    falter replied to a thread Poly 88 case in S-100
    I'm curious about that jumper wire to pin 97... according to the S100 site i'm on that's the sWO status line.. not sure why that's being tapped into.
    277 replies | 12137 view(s)
  • falter's Avatar
    Yesterday, 08:07 PM
    falter replied to a thread Poly 88 case in S-100
    Yes it's the board with the pot on it. That pot is located where the crystal would be on the Rev F board, however on this 1.2 board, 'Y1' is up on...
    277 replies | 12137 view(s)
  • falter's Avatar
    Yesterday, 04:24 PM
    falter replied to a thread Poly 88 case in S-100
    Made some discoveries. First, there is a 180pf (uf?) mica cap installed at Y1. The link from pin 49 to JMP5 has been cut, so the board isn't...
    277 replies | 12137 view(s)
  • falter's Avatar
    Yesterday, 10:10 AM
    falter replied to a thread Poly 88 case in S-100
    Got a little further, I think. I found a cut trace between one of the 8T97s and the RAM above. After reconnecting I now get a solid screen of junk,...
    277 replies | 12137 view(s)
  • falter's Avatar
    June 22nd, 2018, 09:19 PM
    falter replied to a thread Poly 88 case in S-100
    Not sure... the Rev 1.2 I got and the Rev F I had before are very different.. there are chips on the Rev F that don't exist on the Rev 1.2 and vice...
    277 replies | 12137 view(s)
  • falter's Avatar
    June 22nd, 2018, 08:43 PM
    falter replied to a thread Poly 88 case in S-100
    Ah.. I think I might see my problem... The 1.2 VTI board has three 8097s for IC9-IC11. My Rev F board has 8T97... I don't know if there's a...
    277 replies | 12137 view(s)
  • falter's Avatar
    June 22nd, 2018, 07:51 PM
    falter replied to a thread Poly 88 case in S-100
    Well, here's what we've got after borrowing parts from the Rev F to replace the missing ones on the Rev 1.2: A very nice stable picture that I...
    277 replies | 12137 view(s)
  • falter's Avatar
    June 21st, 2018, 09:14 PM
    I regret I've never been good at testing diodes. I put my DMM on continuity.. put black lead on anode and red lead on anode and get: D3 - 8.5M...
    694 replies | 46500 view(s)
  • falter's Avatar
    June 21st, 2018, 05:43 PM
    So as far as my testing can confirm, A1-A3 are the problem right now. A4-A7 appear to do exactly what they're supposed to when keys are pressed. ...
    694 replies | 46500 view(s)
  • falter's Avatar
    June 21st, 2018, 08:12 AM
    Don't know what I did but the ringing is gone now... now I just have wrong bits... for example pressing A should put bits 1 and 7 high (if I've read...
    694 replies | 46500 view(s)
  • falter's Avatar
    June 20th, 2018, 10:06 PM
    I didn't try that but can tomorrow. Definitely the tone on my logic probe sounds better.. and all I did was change diodes. However I have the...
    694 replies | 46500 view(s)
  • falter's Avatar
    June 20th, 2018, 07:55 PM
    Okay so I noticed something odd. On all the 'letter/number' pins, I had a nice, clean, low signal on my logic probe. But when I hit the @-G pin, it...
    694 replies | 46500 view(s)
  • falter's Avatar
    June 20th, 2018, 06:56 PM
    I think I am within an inch of solving this. Keypressed is working -- I actually connected it to the TVT (leaving A1-A7 disconnected) and it prints...
    694 replies | 46500 view(s)
  • falter's Avatar
    June 20th, 2018, 06:31 PM
    Think I found my problem. One of the wires for the @-G keys was, I think, attached to the wrong switch pole. When I removed it temporarily, the...
    694 replies | 46500 view(s)
  • falter's Avatar
    June 20th, 2018, 06:05 PM
    No schematic. It's a very basic 1966 microswitch unit. Each switch has two poles on it. So for letter A, let's say, you have one side of the...
    694 replies | 46500 view(s)
  • falter's Avatar
    June 20th, 2018, 03:12 PM
    Might have a more fundamental problem - if I probe say the pin for P-W, I can clearly see it going from low to high as I hit those keys. But one or...
    694 replies | 46500 view(s)
  • falter's Avatar
    June 20th, 2018, 08:08 AM
    falter replied to a thread Sol20 keyboard issue in S-100
    Thanks guys. I did reach out to texelec and she said she will replace all my pads with the new ones. I kind of wondered why she didn't use mylar in...
    10 replies | 311 view(s)
  • falter's Avatar
    June 20th, 2018, 07:08 AM
    I put a jumper wire in place of the zener and switched to +5v.. I do indeed have +5v on pin 11 now. I do not however have any operation happening...
    694 replies | 46500 view(s)
  • falter's Avatar
    June 19th, 2018, 09:04 PM
    Don himself said the "10 volt stuff is only needed for resistive keyboards. Hard contact keyboards can use plain old 5 or 3.6 volts only." The TV...
    694 replies | 46500 view(s)
  • falter's Avatar
    June 19th, 2018, 08:43 PM
    I may have been wrong... I reversed the zener again and got 1.25V across it. Also replaced the 100uf caps with new ones... nope.. no change. ...
    694 replies | 46500 view(s)
  • falter's Avatar
    June 19th, 2018, 08:20 AM
    Ok I will try that this aft. I am beginning to suspect this encoder has been doing this weird voltage thing all along.. but before I was powering up...
    694 replies | 46500 view(s)
  • falter's Avatar
    June 19th, 2018, 07:25 AM
    falter replied to a thread Sol20 keyboard issue in S-100
    I refoamed using new pads made by texelec. I'm a bit suspicious of their design... they don't have foil on the contact side and the foam is denser...
    10 replies | 311 view(s)
  • falter's Avatar
    June 18th, 2018, 09:02 PM
    No working on that.. so I just want 12v at the striped end, and then ground attached to a 2200ohm resistor with the other end of the resistor...
    694 replies | 46500 view(s)
  • falter's Avatar
    June 18th, 2018, 08:47 PM
    Tried a third one.. same deal.
    694 replies | 46500 view(s)
  • falter's Avatar
    June 18th, 2018, 08:36 PM
    I have a pack of 25 that I bought.. this is the second one I've tried so far. They look new.. labeling looks correct.. possibly they're all bad?
    694 replies | 46500 view(s)
  • falter's Avatar
    June 18th, 2018, 08:19 PM
    Yeah.. doesnt seem to give any voltage reversed. I tried another 1n4738 but same deal.. 2.7v across.. 9.1v across pins 4-11 on the ICs. What...
    694 replies | 46500 view(s)
  • falter's Avatar
    June 18th, 2018, 06:22 PM
    falter started a thread Sol20 keyboard issue in S-100
    I have a weird issue with my Sol.. when I first fire it up.. the keyboard doesn't work. The lighted keys like CAPS and Local react when pressed.. ...
    10 replies | 311 view(s)
More Activity
About falter

Basic Information

About falter
Location:
Vancouver, BC

Statistics


Total Posts
Total Posts
3,022
Posts Per Day
1.11
General Information
Last Activity
Yesterday 10:20 PM
Join Date
January 21st, 2011
Referrals
0
View falter's Blog

Recent Entries

The Ebay Follies

by falter on June 25th, 2017 at 10:09 AM
All hail the $3000 Apple II+!

http://www.ebay.com/itm/142424958928
Categories
Uncategorized