HP82143A Powering a 41 _Extend Your HP41_

[TallKey]

(05-20-2023 09:48 PM)rprosperi Wrote:  

(05-20-2023 08:07 PM)TallKey Wrote:  When is the below statement true?

Be sure Flag 55 is set, which enables the Printer. Possibly, when not set, the 41 f/w doesn't look on the bus to enable it? Just a wild guess...

Flag 21 also enables/disables the printer in some more subtle ways, could also be related?

Testing the theory:

Printer attached, ON.
41CV ON (no battery power for weeks)
MEMORY LOST
CLX
FS? 55
YES
FS? 21
YES

Pull battery pack, display fades to blank.

Several minutes pass, install batteries, display contents are displayed (no ON press), but that is expected behavior.

Flag 21 set or clear, no change to battery pull or to the battery install, IE as above.

Found no difference which is ON first, the 41 or the printer.

Additional testing of the flags with the printer attached:
Printer OFF/ON, 55 and 21 are set.

Summary is am unable to replicate Dr. Mier-Jedrzejowicz printer HP82143A powering the 41.

Haven't near dead batteries to test if the printer supplies some power and then clears the BAT flag