HP-97s card reader inquiry

[[kby]]

What exactly do the CRC numbers refer to (I assume CRC IS CARD READER CONTROLLER [chip])?

(11-25-2020 10:32 PM)teenix Wrote:  

(11-25-2020 01:25 AM)[kby] Wrote:  What signal triggers the shutoff of the card reader motor after the card has passed through the reader? I know MTRS (the ball switch) turns it on, but sunce the head is after the pinch roller, it can’t be simply that getting the trailing edge of the card past MTRS shuts it off. I gave a 9s that after the card has gone as far as it’s going to through, the motor continues to run until the user pulls out the card completely, at which point it shuts off. What might need checking? Thanks in advance

For the 67 and 97 there is interaction between the HP code and the CRC chip which is connected to the switches and sense chip.

The card is tested for the HDS going LO. (CRC 560)
On LO, some code logic is performed (eg. Merge Code CRC 1300, program running? etc)
Depending on Read/Write mode, either CRC 760 or CRC 660 executes to set sense chip WE pin
The motor is then turned on (CRC 260)
HDS is tested for LO - CRC 100
For write mode, the HDS is tested against the WPS for write protect in CRC and tested with (CRC 1700) and creates an "Error" if the card is write protected.
Data transfer takes place (CRC 1700)
The card is then continuously tested for HDS HI - CRC 560
Once out the Motor is turned off CRC 360

cheers

Tony