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HP Forum Archive 20

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HP-41 resource allocation registry?
Message #1 Posted by Håkan Thörngren on 28 Aug 2011, 9:38 a.m.

I wonder if there is a registry of resources for the HP-41? I am thinking of such things as XROM numbers, buffer numbers and the unused bits of register 13?

At the moment I am mostly concerned with register 13 since it is fairly easy to change buffer or XROM numbers. Has anyone documented the use (misuse?) of these bits? I would very much like to allocate a bit of my own there, if I possible.

      
Re: HP-41 resource allocation registry?
Message #2 Posted by Ángel Martin on 28 Aug 2011, 1:03 p.m.,
in response to message #1 by Håkan Thörngren

Here's the modules I know use bits in the c register (status register 13)

1. CCD ROM, used for Continuous Auto Start (CAS), and Lower_Case Alpha flag. From memory, I think they are bits c(16) and c(15)

2. AECROM, used to flag the selected unit mode (Foot, Meter, etc)

I suspect the ZENROM also uses those bits, therefore the incompatibility amongst them.

Will check my notes for others.

Cheers, 'AM

Edited: 28 Aug 2011, 1:09 p.m.

            
Re: HP-41 resource allocation registry?
Message #3 Posted by Ángel Martin on 29 Aug 2011, 3:40 a.m.,
in response to message #2 by Ángel Martin

Incidentally, I considered using one of the "available" bits for the 41Z POLAR/RECT mode, but I decided against it to avoid compatibility issues - so I ended up using one bit in the complex-stack buffer instead for safety, despite the obvious speed penalty.


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