I've got a working 82104A card-reader (I was able to repair the "gummy wheel" and other problems thanks to help I found on the web).
When I use the HP-67's "W/DATA" command to put the contents of the memory onto a card, I can read the card on my 41C, using the card reader — it works perfectly.
When I load an HP-67 era card (from HP's "Standard Pac") onto the 41C, it will load both sides and then say "WORKING" and "PACKING."
However, I can't seem to get the A/B/C/D/E keys to work the way they're supposed to.
On the HP-67, you load data into the stack and then trigger the card's software by hitting the five keys at the top of the keyboard (putting the card into the top slot allows it to work as a label).
On the 41C, once the program from the card has (apparently) loaded, hitting the A/B/C/D/E keys (the top row of keys, so marked in blue) just produces the same result as if I hadn't loaded a program — the leftmost key just does the "sum" function etc. Putting the calculator in "USER" mode gets me "NONEXISTENT" from those keys.
Am I missing something obvious?
Thanks in advance for any help or advice.
Jordan