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+--- Thread: HP41CL Secondary MMU Lockup (/thread-17401.html)
HP41CL Secondary MMU Lockup - Howard Owen - 08-27-2021 05:56 PM
I dusted off my old 41CL yesterday and was playing around with the secondary MMU settings. I accidentally swapped in an undefined configuration and the calculator locked up. Removing the batteries for a time got me a MEMORY LOST. After that, executing "MMUDIS MMUCLR "YFNZ" PLUG1L MMUEN locks up the calculator again. Have I bricked my expensive tech toy?
P.S. This is v5 hardware. The YFNZ version is 4G
RE: HP41CL Secondary MMU Lockup - Sylvain Cote - 08-27-2021 06:09 PM
I have tried very hard to brick my 41CL and I was not able to do so permanently.
Do another Memory Lost and redo your commands, it should works.
If not, remove the batteries, {wait for ... see period below}, insert the batteries and redo your commands, it should works, if not, use a longer wait period.
Wait period: 1 minute, 1 hours, 1 day, 1 week
Sylvain
PS: On a standard 41C/CV/CX I use a paper clip to short the first and last battery connector in the 41 case, but I do not remember if the trick works on the 41CL.
RE: HP41CL Secondary MMU Lockup - Howard Owen - 08-27-2021 06:23 PM
Thanks for your quick reply!
(08-27-2021 06:09 PM)Sylvain Cote Wrote: Do another Memory Lost and redo your commands, it should works.Repeating the steps results in the same outcome. I've tried four or five repetitions, varying the configuration slightly.
(08-27-2021 06:09 PM)Sylvain Cote Wrote: If not, remove the batteries, {wait for ... see period below}, insert the batteries and redo your commands, it should works, if not, use a longer wait period.
Wait period: 1 minute, 1 hours, 1 day, 1 week
One minute suffices to get me back to MEMORY LOST. I'm currently in the first one hour wait period to see if that improves things.
RE: HP41CL Secondary MMU Lockup - Sylvain Cote - 08-27-2021 07:12 PM
Howard,
I am assuming that no physical modules is plugged at the back.
Have you tried "YFNX" instead of "YFNZ" ?
Sylvain
RE: HP41CL Secondary MMU Lockup - Sylvain Cote - 08-27-2021 07:41 PM
Howard,
Maybe your problem is with the 41CL system RAM at page 0x804.
You can brute force a complete clear of the 41CL with the following:
Code:
MMUDIS // disable MMU
"801000-0000" // alternate memory 1 address & reset value
YMCLR // clear alt-mem-1
"802000-0000" // alternate memory 2 address & reset value
YMCLR // clear alt-mem-2
"803000-0000" // alternate memory 3 address & reset value
YMCLR // clear alt-mem-3
"804000-0000" // internal memory & reset value
YMCLR // clear internal memory
"800000-0000" // main memory address & reset value
YMCLR // clear main-mem & creating a memory lostSylvain
RE: HP41CL Secondary MMU Lockup - Howard Owen - 08-27-2021 08:23 PM
(08-27-2021 07:12 PM)Sylvain Cote Wrote: Howard,
I am assuming that no physical modules is plugged at the back.
Have you tried "YFNX" instead of "YFNZ" ?
Sylvain
Oddly enough, loading YFNX seems to have fixed the problem.
RE: HP41CL Secondary MMU Lockup - Geoff Quickfall - 09-05-2021 05:28 AM
And Sylvain strikes again!
Good one.