HP41CL Secondary MMU Lockup

[Sylvain Cote]

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 lost

Sylvain