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HP-41 page 7 safety
09-15-2016, 07:11 AM (This post was last modified: 09-15-2016 07:15 AM by Ángel Martin.)
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RE: HP-41 page 7 safety
(09-14-2016 05:21 AM)hth Wrote:  Is it possible to make a module page 7 safe? That is, to make something else go to page 7 than the HP-IL.

The Extended Functions/41CX it tests the presence of an HP-IL module in page 7 by calling location CHKCST (location 7CDD), but that is really testing the presence of a drive. I suspect other modules may use different approaches to check if the HP-IL module is present? Has anyone investigated this?

The HEPAX would allocate itself to page-7 if available during its initialization, check its CALC_ON polling point code for details. It even goes to page-6 using the same routine. Obviously they must leave blank the hot areas, like the printer extended polling points. They also blanked the entry points to [IUNA] and [IUNALL]. I've done the same for the OS/X and PowerCL modules, which are meant to be both page-6 and page-7 safe...

The HP-IL existence routine I added to the Library#4 checks for the word value at 7000, I thought this was better than the drive check HP used, and it's also compatible with other modules located there - like the HEPAX, the OS/X and the PowerCL.
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Messages In This Thread
HP-41 page 7 safety - hth - 09-14-2016, 05:21 AM
RE: HP-41 page 7 safety - Ángel Martin - 09-15-2016 07:11 AM
RE: HP-41 page 7 safety - hth - 09-16-2016, 04:18 AM
RE: HP-41 page 7 safety - Ángel Martin - 09-16-2016, 05:50 AM

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