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41CL MMU Backup
06-01-2020, 11:48 PM
Post: #28
RE: 41CL MMU Backup
(06-01-2020 10:48 PM)Monte Dalrymple Wrote:  
(06-01-2020 09:24 PM)twoweims Wrote:  Are the "not visible OS" areas in Page 800 (Register 200, 2F0-300, and 3F0-3FF) used for? Are they completely unused or is the Nut processor using them for something that is just not visible to the 41 OS?

As in the original HP41, these locations are not readable. The bus stays 3-state for these addresses.

The RAM corresponding to those register addresses is accessible using the NEWT WCMD however (I think, not sure I ever tried it.)

I was able to YPOKE a value into 800800 then YMCPY 800>801 then YPOKE a new value into 801800 then YMCPY 801>800 then YPEEK the changed value from 800800.
So it looks like YPEEK/YPOKE and YMCPY can read and write from this location! Smile
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Messages In This Thread
41CL MMU Backup - twoweims - 05-28-2020, 10:15 PM
RE: 41CL MMU Backup - Monte Dalrymple - 05-29-2020, 04:07 PM
RE: 41CL MMU Backup - twoweims - 05-29-2020, 04:44 PM
RE: 41CL MMU Backup - Monte Dalrymple - 05-29-2020, 05:49 PM
RE: 41CL MMU Backup - twoweims - 05-29-2020, 08:50 PM
RE: 41CL MMU Backup - Monte Dalrymple - 05-29-2020, 10:09 PM
RE: 41CL MMU Backup - twoweims - 05-30-2020, 01:05 AM
RE: 41CL MMU Backup - Ángel Martin - 05-30-2020, 05:22 AM
RE: 41CL MMU Backup - twoweims - 05-30-2020, 02:32 PM
RE: 41CL MMU Backup - Ángel Martin - 05-30-2020, 03:45 PM
RE: 41CL MMU Backup - Ángel Martin - 05-31-2020, 06:09 AM
RE: 41CL MMU Backup - grsbanks - 05-30-2020, 08:27 AM
RE: 41CL MMU Backup - Ángel Martin - 05-30-2020, 03:52 PM
RE: 41CL MMU Backup - Monte Dalrymple - 05-30-2020, 06:47 PM
RE: 41CL MMU Backup - rprosperi - 05-30-2020, 10:36 PM
RE: 41CL MMU Backup - Monte Dalrymple - 05-30-2020, 11:58 PM
RE: 41CL MMU Backup - rprosperi - 05-31-2020, 03:00 AM
RE: 41CL MMU Backup - Monte Dalrymple - 08-07-2021, 02:07 AM
RE: 41CL MMU Backup - Ángel Martin - 05-31-2020, 06:55 AM
RE: 41CL MMU Backup - Monte Dalrymple - 05-31-2020, 06:22 PM
RE: 41CL MMU Backup - twoweims - 05-30-2020, 08:26 PM
RE: 41CL MMU Backup - Monte Dalrymple - 05-30-2020, 10:07 PM
RE: 41CL MMU Backup - twoweims - 05-31-2020, 06:30 PM
RE: 41CL MMU Backup - rprosperi - 05-31-2020, 06:51 PM
RE: 41CL MMU Backup - twoweims - 05-31-2020, 07:44 PM
RE: 41CL MMU Backup - rprosperi - 05-31-2020, 08:09 PM
RE: 41CL MMU Backup - twoweims - 06-01-2020, 09:24 PM
RE: 41CL MMU Backup - Monte Dalrymple - 06-01-2020, 10:48 PM
RE: 41CL MMU Backup - twoweims - 06-01-2020 11:48 PM
RE: 41CL MMU Backup - Monte Dalrymple - 06-02-2020, 01:42 AM
RE: 41CL MMU Backup - grsbanks - 06-04-2020, 07:14 PM
RE: 41CL MMU Backup - Monte Dalrymple - 06-04-2020, 08:50 PM



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