Interesting TI-59 problem

[John Garza (3665)]

I have a TI-59 that appears to have an intermittent problem locating common labels in a program.
Some details:

* I wrote a simple factorial program using DSZ for looping and the common label CLR.
* Initially it works. But after a half minute or so it fails at the step calling CLR and flashes.
* Listing the code on the PC-100A before and after shows no changes.
* Loading the same program (same mag card) to another 59 and running works without flaw.
* Changing the DSZ branching from a label to a line number on the original machine also works.

So it seems to me this may be an obscure issue where it can't locate a label in memory.

-John

[toml_12953]

(08-11-2023 12:31 PM)John Garza (3665) Wrote:  I have a TI-59 that appears to have an intermittent problem locating common labels in a program.
Some details:

* I wrote a simple factorial program using DSZ for looping and the common label CLR.
* Initially it works. But after a half minute or so it fails at the step calling CLR and flashes.
* Listing the code on the PC-100A before and after shows no changes.
* Loading the same program (same mag card) to another 59 and running works without flaw.
* Changing the DSZ branching from a label to a line number on the original machine also works.

So it seems to me this may be an obscure issue where it can't locate a label in memory.

-John

It sounds like either the RAM chip or the clock might getting temperature sensitive as it ages. Once the program stops running, the RAM settles down to its original value. You might try to put it in the refrigerator while it's running to see if that affects how long it can run.

The 59 had some strange quirks. I once had a 59 that couldn't save a particular program sequence in a certain memory location to mag card. Any other key sequence was fine but if I used one particular sequence in a specific step of memory, it wouldn't write properly.