HP-71B Auto on

[J-F Garnier]

(02-09-2023 03:49 PM)Sylvain Cote Wrote:  My main test setup was:

• 6 x HP-71B (1BBBB) with HP-IL module (1B)
• 2 x PIL-Box
• 1 x pyILPER (with virtual scope and virtual display)
• 1 x pyILPER (with virtual scope and virtual tape).
  

One of the tests involved saturating the HP-IL loop with asynchronous messages between all the 71Bs for an extended period of time. (~120 hours)

This specific test revealed two faulty HP-IL interfaces.
These interfaces were working correctly with light traffic but they failed under serious stress.
The symptom was that at some point the 71Bs who had the faulty interfaces were experiencing a memory lost after several hours in the tests.
Swapping interfaces between machines revealed that the issue was following the HP-IL interfaces and not the 71B computers.
Once those interfaces were removed, the communication worked for the duration of the test.

This is particularly interesting. So it seems there are some hardware variations of the HP-IL module 1B.
I already suspected it for the module 1A, because some (not all) of them have problems with the PIL-Box, and I was able to identify timing variations, that don't harm with the genuine HP-IL devices but do with the PIL-Box.

J-F