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HP-41C Extended Functions - 4K module?
03-01-2018, 04:16 PM
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HP-41C Extended Functions - 4K module?
Is the HP-41C Extended Functions module a 4K module? Is it bankswitched? I checked the very good reference at http://calc.fjk.ch/db/hp41mod.php, but the table column that specifies module size is blank for all versions of this module.

It only has one ROM ID (25) which I expect means that it is not a conventional 8K module occupying two 4K I/O address spaces. I think the HP-41CX was the first commercial application of bankswitching, and the Extended Functions Rom was introduced about a year and a half before the HP-41CX. I thought that the HP-41 Advantage Module (1985?) was the first commercially available bankswitched module from HP, and if so that would indicate that the Extended Functions module is not bankswitched and fits fully in a 4K page.

When the Time Module and the Extended Functions Module were built into the CX, they added the CX Time and Extended Functions, and as such, the HP-41CX was advertised to have and additional 12K ROM over the HP-41CV (4K for Time, 4K for Extended Functions, and 4K for CX Extended Functions?), but this still does not answer the question definitively. The CX Time and Extended Functions are not many, and may only continued to fill up a (possible) partially used 2nd bank of an Extended Functions module.

Does anyone know for sure if the Extended Functions module ROM code fits fully in 4K? Did HP publish this information for the Extended Functions module?
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HP-41C Extended Functions - 4K module? - Dan Grelinger - 03-01-2018 04:16 PM



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