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pyilper and logging of printer files: where are they?
10-26-2021, 09:04 PM
Post: #7
RE: pyilper and logging of printer files: where are they?
(10-26-2021 06:04 PM)J-F Garnier Wrote:  
(10-26-2021 04:50 PM)jsi Wrote:  From the pyILPER manual:
Device enabled checkbox: If checked, the virtual HP-IL generic printer is available and can be used as HP-IL device. The HP-IL loop must always be reconfigured after activation or deactivation.

Enabling or disabling devices in pyILPER is like adding or removing devices from a HP-IL loop which needs a reconfiguration of the HP-IL controller. Otherwise a new device will not be accessible. To reconfigure the loop switch the HP-41 off and on.

With the (real) HP-41, a calculator off/on is usually not needed, since the 41 reconfigures the loop at each operation (except with advanced modes of the X-I/O module). This can be checked with the scope display (AAU, AAD 1 sequence). This was designed in this way intentionally to make the HP41 HP-IL works mostly automatically without user actions, at the expense of redundant HP-IL traffic.
With the HP-71B, yes an off/on cycle or a RESTORE IO is needed.

[Edited: be sure to be in AUTOIO - this is the default mode]

Thanks for this note of clarification and rationale J-F. I've wondered for years why the 41 seemed more 'robust' about loop changes, I did not realize it configured at the start of every transaction. Although easy to criticize this approach (for the overhead cost) it makes sense to me that calculator users are less likely to be sensitive to such nuances and more likely to simply hook things up and pull data.

I keep learning.... thanks!

--Bob Prosperi
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RE: pyilper and logging of printer files: where are they? - rprosperi - 10-26-2021 09:04 PM

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