smaller HP 82166A with 32-pin connector

[Klaus Overhage]

Thank you for your explanations. Then this device is probably not so strange and could work. It already has the same MCU as the production unit. But the ICs are still rotated as in your prototype. That explains probably the strongly deviating PIN assignment of my variant compared to the technical manual. The name is displayed by the HP-41CX with CCD module in Catalog 0 as HP82166A.

In the meantime, I was able to build the simple circuit from the book "Control the world with HP-IL", page 42. Instead of a 74C373, a 74HCT573 is used. The tests, whether so 8 LEDs can be switched were all positive. The DA0-DA7, DAVO, RDYI, DACI, + 5V and GND connections are all correct. The "Count" program on page 44 ran to 255 in 96 seconds. With the HP-71B, a flickering light looks very pretty.

Code:


10 RESTORE IO
20 A=DEVADDR("%64")
30 ENDLINE ""
40 X=1
50 FOR I=1 TO 8
60 OUTPUT :A; CHR$(X)
70 X=2*X
80 NEXT I
90 FOR I=1 TO 8
100 OUTPUT :A; CHR$(X)
110 X=X/2
120 NEXT I
130 GOTO 50
140 END