A8 BASIC freeze ups / funny behavior on my 600XL + 1064

[Probabilitydragon]

Hi, Forum!

 

After my initial excitement of playing around with my 600XL, it's been mostly left sitting idle on my table during the past months...

 

But this morning, I did some BASIC coding just for fun. A silly routine that makes random sounds, characters and colors in GR.0 just for the heck of it.

 

And, after having versions of my program that worked and after typing a new command line, RUNning the program just freezed BASIC.

 

Interestingly, typing LIST would also freeze the machine.

 

Now, as a kid, I recall something curious happening now and then with BASIC on my machine. It would have, perhaps, frozen like this occasionally. Or, sometimes, the BASC LISTing of the program would become "corrupt" for now reason and, if I remember correctly, typing LIST would produce the beginning of the program, and stop at a line that would display erroneous commands and no <RETURN> character at the end of line. 

 

The behaviour I'm describing happened decades ago so I don't remember the details. But I remembered being even a bit scared that my dearest computer, my most prized possession, was kind of going crazy occasionally

 

Anyway, the question is not very important but it's something that has been puzzling me since 1985 - why does my 600XL behave like this? Is it something typical of the on-board ROM basic, fo A8's in general, of the 600XL, of the 600XL+1064 combo, or has there been something wrong with my machine ever since I got it? Nothing wrong with the memory, just ran a mem test, all green.

[TGB1718]

I believe this behaviour can happen in Rev B, Have a look at this thread, Post #11 has a peek to see what version is in your machine

 

 

 

[Rybags]

If it just locks up at some random time then probably a hardware issue.

 

If it locks up when you've entered a command but otherwise lets you type normally beforehand then it's almost certainly the bug within the Basic Rom.

[Probabilitydragon]

Oh yeah, that had been discussed relatively recently here, thank you for pointing me to the thread. I probably have rev b basic, but will peek the value at 43234 to find out!

[Probabilitydragon]

rev b here, so the mystery of three and a half decades is solved.

[Sugarland]

I don't think it's a rev b issue. Sounds like a hardware issue to me.

[Probabilitydragon]

@Paul Lambert had exactly the same symptoms in the earlier thread as I did this morning. He’s running rev c, so it’s probably not a rev b issue. 
 

Might have happened because my break key is dead, and I’ve been using the reset key.

 

But the symptoms have been there since the 80’s with this machine, and I was diligently using the break key back then ? so, hard to tell if it’s a hardware or a software issue ?

 

[Paul Lambert]

For what it is worth, it turns out that the freeze-up on in my case was the result of a machine language routine placed in a part of ram not accessed by the BASIC portion of the program. Had I simply saved my work as I went along, I could have reloaded the program after a seize-up. Now that the program is completed and saved, there has been no problem, as a later part of the program returned control from outside the machine language routine that had been seizing up the system.