Detailed test of the M1000 reader with the internal interface

EOF LED NOT LIGHTING

I had an LED installed in the reader, wired to Brian's interface design, which should be toggled on and off by repeated presses of the pushbutton just below it. Nothing was lighting. I determined that the NAND gate driving the LED had failed, but fortunately there are two unused gates on the same IC.

I cut some traces, rerouted signals with wire jumpers, and soon had the LED working properly again. 

RESEARCH INTO THE Q CHARACTER AND PICK CHECK

When the card reader attempts to pick up a card six times but never sees its edge pass the photocells, it detects a pick error. That Pick Check is indicated by a lamp illuminated on the reader itself but the only way the PC program will know is that the READY status goes off. 

The program should accept the pick command, begin card movement, capture all the eighty columns of data, then stream back 160 bytes preceeded by an '=' character and followed by a status character.

If a pick check occurs, the reader should be sitting with pick active but not respond with anything. Pressing the EOF button returns a '!' character to indicate that the read was terminated. Clicking stop ont he application cancels the pick. Otherwise there shouldn't be a status response to the pick command P but this machine is returning a 'Q' character. 

RUNNING A DECK THROUGH THE READER TO SEE WHAT IS TRANSFERRED

I have a short deck, an RPG program for the IBM 1130, which I am using to test the reading system. I ran it up until the first pick check then closed the program so that I could view the resulting file. The outcome was that the file was not created and the read was cancelled due to pushing the EOF button since no contents had been read.

I switched over from Brian's application to a terminal program where I could issue the commands and see the responses directly. That showed me that no content was being collected or transferred by the microcontroller, although the control logic of the card reader didn't detect any errors. I would type the P command and once we had a pick check, it would return the status character Q (Pick request active and ready status; the ready status is inaccurate in a response to a pick so it can be ignored).

Some scope work attempted to view the IMST signal (the clock phase D is issued on this motherboard line whenever a read is being attempted, but the exact timing of start and end of card columns gates that forward to the IM signal delivered to the interrface. There would be one pulse per column for card columns 1 to 80, telling the microcontroller when it was safe to sample the 12 data lines for the card rows 12, 11, and 0 to 9. It is my suspicion that this pulse is not getting to our interface.