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(SOLVED) 41CL - DOUBLE HEPAX ACCESS and MMU CONFIG
08-22-2019, 05:33 PM
Post: #40
RE: (SOLVED) 41CL - DOUBLE HEPAX ACCESS and MMU CONFIG
(08-22-2019 02:30 PM)Sylvain Cote Wrote:  Doing a backup/restore of the MMU configuration sets to/from a HP-IL medium is more problematic.
The problem is that I need to bring the information from/to the 41CL FPGA MMU world into the HP-41CX world before being able to make a backup/restore to/from a HP-IL medium.

I need to do some reading of Monte documents and do some experimentation before I can come up with the solution.
There will be some days before I will come back to you.

Sylvain

My limited understanding of the Hepax RAM format says that it might be fairly simple. If you look at page 804 in RAM where the MMU registers are, the first 12 bytes are almost unused. And everything above 804400 is unused. So the Hepax page pointers can be easily set. The word at 804000 is used for the 41C register address, which means that you probably will need to copy page 804 to some other RAM page before you can make it into a Hepax RAM page for transfer. I am assuming that the Hepax RAM can be filled with binary data. If this is not the case then it become more complicated, but there is plenty of space in the page to massage the data to/from any required format.
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RE: (SOLVED) 41CL - DOUBLE HEPAX ACCESS and MMU CONFIG - Monte Dalrymple - 08-22-2019 05:33 PM



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