HP-97s card reader inquiry

[[kby]]

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

[[kby]]

Figured out my problem, although still interested in knowing what the logic is. Problem was the ribbon cable was inserted shifted over a bit so many contacts on the cable bridged two contacts in the connector.

[teenix]

(11-25-2020 02:16 AM)[kby] Wrote:  Figured out my problem, although still interested in knowing what the logic is. Problem was the ribbon cable was inserted shifted over a bit so many contacts on the cable bridged two contacts in the connector.

I posted an oscilloscope image of the card reader signals here. It is for a 65, but the 67 is the same.

https://www.hpmuseum.org/forum/thread-15...#pid139076

Hopefully helps with the answer.

cheers

Tony

[teenix]

(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

[[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

[teenix]

(11-28-2020 03:24 AM)[kby] Wrote:  What exactly do the CRC numbers refer to (I assume CRC IS CARD READER CONTROLLER [chip])?

Pretty sure it is the octal code of the actual command, and yep :-)

cheers

Tony

[[kby]]

Is there a list of opcodes and their descriptions somewhere?-kby

(11-28-2020 09:00 AM)teenix Wrote:  

(11-28-2020 03:24 AM)[kby] Wrote:  What exactly do the CRC numbers refer to (I assume CRC IS CARD READER CONTROLLER [chip])?

Pretty sure it is the octal code of the actual command, and yep :-)

cheers

Tony

[teenix]

(11-28-2020 08:22 PM)[kby] Wrote:  Is there a list of opcodes and their descriptions somewhere?-kby

As best as I can determine.

Crc060 - set display digits
Crc100 - test ready
Crc160 - test display digits
Crc260 - motor = on
Crc300 - test w/prg switch
Crc360 - motor = off
Crc400 - a key was pressed
Crc500 - test if a key was pressed
Crc560 - test if card inserted
Crc660 - write mode
Crc760 - read mode
Crc1000 - set default functions for A - E keys
Crc1100 - test if default functions for A - E keys set
Crc1200 - set merge
Crc1300 - test merge
Crc1400 - set pause
Crc1500 - test pause
Crc1700 - read/write from/to card

cheers

Tony