Some HP-50G Questions

[cyrille de brébisson]

Hello,


>1. Try to recover memory: A does not register
This is weird and I have never heard this... However, I might have some suggestions.
Trying to recover memory starts the calculator on a complex loop trying to locate valid objects in memory, figure out what objects belong to what and store all that back without overriding anything else...
If might be that it does take some time at the beginning, when you press A, to find the necessary space to generate enough free memory to run the code that displays the "recovering" message. But I am not certain on this one as I do not remember how the code was implemented (sys-RPL or ASM).


>2. reset hole
I do not remember the 50G mechanical. At one point this "hole" gave you access to a piece of bendable metal that was also the back EMC shield of the calculator. That grounded shield would bend down to the PCB and contact it when pressed. Closing the circuit and causing the reset. This explains the "shininess". But it might have been on the 49, not the 50. Other calcs like Prime use a switch.

>3.MATRIX, ve ARRAY...
From memory CAS objects are MATRIX (lists of lists internally), while ARRAY are SYS-RPL ARRAY type objects (which have fixed length sizes like complex or reals).

Cyrille