Thursday, December 16, 2021

Archiving steadily with pauses to battle Documation card reader isI asues

 PROGRESS ARCHIVING CARD DECKS

I completed reading and organizing tray 9 of the 15 trays of software I own. In addition, am down to 14 card boxes of unread software. Overall I have less than 50,000 cards remaining to process. 

One item I discovered while archiving is a complete distribution deck for the DNA Systems RPG-II compiler, a product they sold to replace the RPG compiler that comes with the 1130 Disk Monitor System. Presumably this is a more complete and modern compiler. 

M600 CARD READER ADJUSTMENT BATTLE AND BALKY PICKING

The M600 reader is the one that I used for all the cards I have read to date. Its picking declined as I described in a prior blog post, due to the picker arm becoming loose on the \solenoid shaft. I started through the 24 steps to adjust the picking mechanism, but discovered some issues I have to resolve before I can successfully set this machine up.

The loose picker arm created scratches where it rotated against the aluminum frame, right where the vacuum supply is delivered to the picker arm. When I used a .002 feeler gage to set the gap, the picker arm would stick and not snap back to the ready position. I had to make the gap much wider which defeats the purpose in order to have the arm operate with almost no binding events. 

I believe I have to disassemble the mechanism and polish the surfaces before I can make the adjustment as required. This will be a multiple hour project which I deferred while the reader was still reading cards adequately. 

Sadly it has degraded again to the point where it isn't good enough to continue reading the decks with that machine. I will try to get the M1000 fully operational since i know that picks superbly, but also have the repairs for the M600 to restore it to a useful state.

M1000 READER FLAKY BEHAVIOR

I modified my card extender for the reader to install pins for all the signal lines. That makes it easy to hook up the logic analyzer and/or the oscilloscope for debugging. It took a couple of hours to finish the card but I put it into use.

Last time I tried the reader, it was sporadically generating garbage input to the controller and generating Read Checks. I set up the extender and some logic analyzer wires to troubleshoot this situation, but the reader was no longer producing Read Checks. 

I methodically checked all the signals for the backplane to see where the reader might be malfunctioning. Initially I saw some signals that weren't operating properly but after I began documenting the state I found the reader seemingly working properly. That is the logic which controls the card flow and generates the output signals for each column were working fine.

I then hooked up the controller to my laptop and tried to read the card decks. What I saw was the complete absence of any data being returned to the controller. The laptop program knew that it hadn't successfully read any cards. 

Next up, I moved the extender to the clock card so that I could watch the Index Marker pulses being presented to the controller. I discovered that the backplane signals that worked well before and controlled the card column behavior were failing again. 

This is very erratic and quite difficult to debug when problems come and go. I left the shop and will devise some strategy to figure out what is going awry. I might have to set up the logic analyzer and record everything in order to see what drops out when it the flaky behavior arises. 

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