Making great headway archiving card decks, but at least one more demon resides in the card reader

VERIFICATION THAT MY MODIFIED READER CORRECTLY READS COLUMN 80

Since my modifications to the reader affected the change that was giving double CR81 pulses, it was possible that my new circuit was being activated at column 80 time rather than the intended column 81 time when all rows should be dark.

My circuit forces the top row (12) to be seen as dark when at CR81 time. This compensates for errors reading cards with a right hand side diagonal notch, since the light may leak around the notch into row 12 causing a Read Check stop. If this circuit was active at column 80 time, then it would also ignore any hole in row 12 on that column. 

I took a card that had row 12 punched in column 1, flipped the card so that the column 80 side entered the reader first (to be read as column 1) and then checked what was read. You can see the backwards text because I flipped the card and indeed the last column does read the hollerith character C (row 12 plus row 3) properly.

Rightmost column (80) has holes in 12 + 3 for a letter C

 FAST AND ACCURATE ARCHIVING OF COBOL AND RPG COMPILERS

This reader is not only faster because it is 1000 cards per minute versus the 600 cpm rating of the M600, but also because its picking mechanism is in good condition and rarely fails to pick. 

First video above is loading the deck into the M1000 reader. Below is the process of reading via the cardread.exe application on my laptop, through USB to the controller I built into the reader.

I ran about 1500 cards of the COBOL compiler and another 1500 of the RPG compiler through the reader in batches of a few hundred cards each. Extremely few pick checks or reading errors. 

ARCHIVING OF IBM 1130 DIAGNOSTIC DECKS 

I then moved through a few thousand cards of diagnostics. In this case, each deck is quite short so the time to name and process each individually is much longer than the actual reading plus verification passes on the reader. 

In the video above, you can see a verification pass where the card deck is read a second time and compared hole for hole with the file that was created during the 'read' pass. At one point it has a pick check, thus a pause until I hit reset on the reader to continue the reading.

SYMPTOM RETURNS AS ONE INTERMITTENT AND THEN SOLID FAILURE

I had a pick check while reading a deck, but when I reset the reader to retry I saw that it was back to the same failure where it didn't see that the card was actually going through the read station. That was the symptom when the OneDark signal was prematurely active due to the hairline crack in the trace. 

I tapped the card cage, hit reset and we resumed reading successfully. However, after a few more decks being processed, the symptom returned and was solid this time. Very frustrating. Might not be the same issue exactly but certainly the same symptoms. Will have to call the Ghostbusters for this one.