Attendees: Bill Newman, Bill Worthington, Bill Flora, Bob Erickson, Douglas Martin, Ed Thelen, Frank King, George Ahearn, Glenn Lea, Joe Preston, Ron Williams, Stan Paddock
Visitor(s): Robert Garner had two more visitors and Don Luke had one.
Joe Preston continues to work on the last failing 729 of the German system. He is making good progress. Now the tape drive waits until a tape is installed before it tries to load the tape.
During a demonstration on the German machine, the 1403 printer dropped a column. Frank King came to the rescue and replaced one of the 66 hammer driver cards. He commented how dirty that card was.
Stan pulled all of the hammer driver cards and went outside to brush the dirt off all of them.
When Stan installed the hammer driver cards back in, the German machine decided to stop running programs. As time was running late, we had to leave the machine as it was and we would attack it next week.
Work on the card reading problem with the Connecticut machine, we took a suggestion from Jud McCarthy in Boca Raton Florida. We created a card deck of 80 cards. The first card had a ‘G’ punched in column one. The second card had a ‘G’ punched in column one and two. The 80th card had a ‘G’ punched in all 80 columns. A program (PTEST) was written that read cards with the I/O check switch off. It would print the data and add an ‘E’ in print position 82 if a card read error was sensed.
If the card had 63 or less ‘G’s, there was no errors. Starting at card 64, more errors and columns started to be missing data.
Another deck of cards were punched but using an “*”. The ‘*’ has three punches per column instead of two like the ‘G’.
When this deck was run, the errors started after the 25th card. The errors were sensitive to the number of absolute punches in a card.
George Ahearn suggested the problem might be temperature sensitive. We pulled the temperature sensing card over the main memory stack that contained the three bi-metallic thermostatic sensors. The first is specified to be closed until the temperature reaches 70 degree F. The second opens at 82 degrees F and the last one opens at 90 degree F.
Under testing, the first bi-metallic thermostatic sensor worked as designed. The second (hotter) and third (hottest) failed open. At this time, we had run out of time for that day.
Questions we had were:
1. What happens if the temperature sensing card reports the correct temperature?
2. What happens if we run the cards starting with the 80 punches first instead of last?
3. What happens when the punches go from right instead of left to right?
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