Something similar happened to me, it's Doors CSE. I already told the creator (KermMartian) about this, and he says that he will fix that when he updates Doors CSE again. As for your calculator, I'm afraid you'll have to hit the reset button on the back of the calculator.

Hi and welcome to the forums.

Have you tried resetting the calc by pressing the button on the back with a pen? That generally fixes stuff related to ASM programs (eg if a game freezes). This will clear all your RAM, though, so you might lose some programs.


Question: When you started charging your calculator, was Doors CS 8.1 running? I am curious because MirageOS 1.1 had a similar issue happening when you plugged a link cable into the calc link port (the password thing would appear then the calculator would go haywire, often with a RAM clear as a result)

What happened to me is that I was running DCSE and then I removed the cable, and then it froze.

This is a bit late but. . . .


The USB hardware isn't very well understood. Generally, most 3rd-party software just ignores it. This causes problems if they take over interrupts, because USB can also generate interrupts. When you connect or disconnect the USB cable, an interrupt is generated. If the running software has taken over interrupts, hasn't disabled USB interrupts, and doesn't handle the interrupt, it will freeze because the interrupt keeps firing. Eventually, the stack will overflow and wipe all RAM. Eventually, I hope to have some fairly simple code that can disable and re-enable USB, so assembly programs won't crash.


Also, the TI-8x series originally ran on AAAs, so TI had no reason to include a low-voltage shutdown circuit on the ASIC. The LCD backlight dimmer has one, but it cuts off at a voltage (2.0 V) way lower than the voltage at which the battery has been damaged---and the dimmer is connected DIRECTLY to the battery (it's really easy to see the giant trace on the PCB). So if the calculator crashes with the backlight on, the backlight will remain on until well after the battery can't hold a useful charge anymore (unless there's a hidden circuit elsewhere that forces the control pin on the dimmer low).

Would this program be in the form of an OS patch so that no current ASM program need to be modified in order to fix that issue or would this be in the form of an ASM routine released on ticalc.org that people can insert in their respective programs?

Er, a patch seems like a little too extreme a solution.

Could you clarify about if an ASM program is left running without crashing, then if the battery is safe or not and if the calculator will just shut down? I might be missing something, though.

It depends on whether the program takes over interrupts. TI checks for the low battery condition in their interrupt handler ---or at least they used to, I should probably check that---, so if their interrupt handler is still active, the OS can see the problem and shutdown. I should definitely look into how TI checks for the low-battery condition so that people know how to make their own interrupt handlers do it.