Friday, December 31, 2021

Varied tasks at shop while waiting for scale and drive belt

 WAITING ON TOOL TO FINISH M1000 CARD READER REPAIR

In order to set up the card reader after I swapped in a drive belt from the M600, I will need to set two adjustments, using a feeler gauge and a spring scale. Until the tool arrives tonight, I can't get any more done on the reader. In the interim I accomplished a few minor tasks in the workshop.

TESTING MY MODIFIED CARDREAD.EXE APPLICATION WITH NON-WORKING READER

I hooked up the laptop to my external interface box for the M600 card reader. Although both readers are currently not operational, I could at least verify that the modified application communicates with the interface and picks up status correctly.

I was able to connect, see the hopper and error status that occurs when the reader is not powered on, and watch the EOF status reflect the pushbutton and LED on the interface. I also checked that the new "Trunc" button is disabled when it is not appropriate to use it. 

It should only enable when we are verifying a binary mode deck and have at least one card that matched, after which a miscompare occurs between the originally read file and the one being passed through the reader for verification. It will be reset by use of the button or if either the Start read or the Verify buttons are activated. I need an operational reader to test out that functionality and the proper truncation of the original file to the end of the last correctly verified card. 

DISASSEMBLING M600 PICKER MECHANISM TO DEAL WITH ITS ISSUES

When I attempted to set up the M600 reader, the step that sets the picker foot .002" above the vacuum input plate caused it to lock up and not feed. I had to open the gap quite far before it no longer got stuck. The surface between the vacuum plate and picker foot is roughed up, causing the binding. Without a good tight seal the reader doesn't have enough vacuum to guarantee good picking, which is an issue resulting in not only pick checks but errors reading or verifying.

Opening the picker mechanism to restore it

I wanted to disassemble the entire mechanism, smooth the roughed up surface, correct any other issues and get this back into spec. After disassembling things I noticed some magic marker with .010" written near the foot - clearly the setting that let tried to balance low vacuum with the binding of the rough surface. I also see that the shaft on which the picker foot is hooked is chewed up a bit by poorly positioned and tightened set screws. 

Signs that this reader had problems

PUTTING THE IBM 1130 CONSOLE BACK TOGETHER

I had developed a single large PCB with mounted incandescent lamps as a replacement for the poorly designed original boards with SCRs and lamp holders that are a nightmare when a bulb needs replacing. Now that my board is working properly and fits well into the honeycomb, I had to reassemble the console pedestal where these lights will reside.

The plastic honeycombs have the faceplate attached with the legends and openings for the roughly 160 lights. They screw into metal brackets on the sides which themselves are bolted to the insides of the enclosure. On either side of the faceplate there are white metal rectangles that hold the Emergency Stop and Run Mode Switch. These are bolted down to the front of the enclosure and adjusted to fit with uniform gaps to the faceplate. Finally there is a terminal strip that brings the AC power, lamp test and ground lines to the enclosure. 

Run Mode switch from the back

Emergency Stop pull switch from the rear

In addition to the strip, there are about 160 individual wires with clips that push onto pins for each of the lights to be controlled. My PCB has pins in the same relative positions as the multiple small PCBs IBM used. It will be easy to plug them in once the light PCB is placed onto the rear of the honeycomb.

I need to make up some soft wedges to hold my PCB against the rear of the honeycomb, otherwise we are ready to install it and wire it up for testing. There is one other contingency before I can test - I need to get a 240V outlet installed in the workshop. 

FURTHER TESTING OF THE P390 SYSTEM 

I brought up the P390 system, having corrected the seating of the Intel Ethernet card in slot 2. That was giving errors when OS/2 booted up, but now everything comes up cleanly.

I had been worried about the CMOS battery status but with a proper battery installed it has been holding its settings for weeks of downtime. I feel good about the state of this system. Ahead are efforts to connect the 3174 terminal controller to the P390 via WAN cables and to install and configure my 370 parallel channel card for bus and tag peripheral access.

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