Sunday, July 31, 2016

1132 power connector fixed, display panel fixed on replica, signage done for VCF West


I have removed the mounting screws for the power connector and have pulled it out from the frame a bit, to allow me to rotate it a bit and gain a bit more access. I have been unable to get the mounting nut to fit inside the back of the connector and grab threads from the front inserted jackscrew.

I tried to glue a bit of plastic soda straw to a face of the nut, so that I could insert it into the rear of the connector and even turn it slightly. Assuming I can get the jackscrew and its nut tightened, the next problem will be putting the 1132 connector back into its position on the power panel.

Four guide pins are used to hold the connector onto the frame. Unfortunately, the lock washers and nuts have to be held in place from the side of the power panel, while the threaded rods of the pins are inserted from the front. This is quite challenging because of extremely limited access.

I took a bit of paper town, inserted it between a 1/4" socket and the nut on the end of those guide pins. Pushing down caused the nut to be wedged into the socket, the pin unthreaded, and the socket potentially used to hold the nut in place in back while I attempt to thread in the pins from the front.

It took two improvisations to even attempt this reassembly - the glued on straw segment and the paper wedged nuts in sockets. The first of these worked like a charm! I now have the jackscrew tightened into place on the connector.

Unfortunately, the socket is too wide to fit into the narrow notch in the back of the connector where the lockwasher and nut must go. I removed the air duct for the internal disk drive, which gave me more access to the top two areas. I should be able to get those top two guide pins properly connected and tight. The problem will be with the bottom two.

I can reach my hand in and touch the spot where the pin threaded rod comes through, but I can't put the hand in if it is closed even a bit to hold a nut and I certainly can't move the nut around to put it into position. Even with the relatively easier top two pins, I am manipulating the nut with a single fingertip, sliding it down, changing its orientation and getting the thread to catch.

The top two pins are installed as is the bottom left. I had to wedge the small nut between my fingertip and the vertical wall of the power frame, slide it deep inside and up to the point where the guide pin threaded rod emerged, then carefully move things until the threads caught. To do the fourth and final pin, I have to slide the nut even deeper and then move it up into a notch around behind the bottom of the connector body.

After wrestling with this last guide pin for another hour, then losing the nut somewhere, I came to a realization. Three guide pins are plenty to position and guide the male connector as the jackscrew draws it carefully into the female connector.

I turned to the 1132 male connector, which still had the jackscrew female attached to the jackscrew. I took it off, inserted the screw properly in the connector, and put things back together. With all my cables reconnected, except for the SAC power cable whose connector donated the female jackscrew for this repair, I jumpered the power pins on the SAC power cable and brought my system up.

As I had suspected, the problem with the printer spewing paper was just an effect of a partially disconnected power cable. The AC power pins were still providing power, but the logic card voltages of +3, -3 and +6V were not going to the printer. With no logic to set it up properly, the printer was going to do bad things.


I sprayed the texture coat, sand colored stone finish, last night so that I could put on the first color coat of pebble gray early today. Later in the afternoon I added the final pebble gray color coat. Once these are dry enough, tomorrow, I will reattach them to the 1130 frame. That will leave only the section of the top that holds the display pedestal and is the nook into which the console typewriter sits.

I printed the final signage for the booth, laminated some of them while inserting others in acrylic stands. This includes three original IBM magazine full page ads that I laminated for display. I feel good enough about the signage that I can put all my attention on the remaining tasks:

  1. Finish 1132 power connector repair
  2. Test all demonstrations as they will be done
  3. Repair 1130 replica display panel that was broken last week
  4. Mount new-old rotary mode switch on pedestal
  5. Replace top metal on replica
  6. Build typewriter and pedestal base from MDF
  7. Paint typewrite and pedestal base
  8. Install typewriter and pedestal base
  9. Install pedestal on base
  10. Load fpga with replica logic
  11. set up power system for replica
  12. connect all controls to FPGA
  13. test replica and repair any issues
  14. fit IO selectric in place on replica
  15. Temporarily affix the console bit switches in place
  16. Secure internal disk drive heads for transport
  17. Disconnect all cables and secure them
  18. Swap power plug on 1130 for L6-30
  19. Cut and install replica cover braces
  20. mount replica covers
  21. move replica to staging area near real 1130

I have retrieved all the connector boards, power supplies and other bits that were used to run the replica. Now I will have to carefully note where every connector and signal should go, validate the cabling and other parts, then hook it all up.

I completed tasks 3 and 4 - repairing the replica's display pedestal panel, where the plexiglas panel had broken off when the stand tipped over. This has been quite hard to get secure, the last time I had drilled holes, glued in 1/8" plastic rods and then hooked clamps over the back of the rod, inside the pedestal head. Those broke off.

This time, I used 3mm flathead black screws through those 1/8" holes in the plexiglas, secured to locknuts inside the pedestal head. Three of the four are properly secured, the fourth is a friction fit but should hold okay without the locknut. I also secured the rotary mode switch plate firmly onto the head.

With the 1132 power connector repaired (see section above), I had now completed 3 of the 21 tasks. Eighteen to go, Three relate to the real 1130, the remainder are for the replica, to complete the cosmetics and get it working.

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