Tom Greene wrote:
> On Aug 29, 7:08 am, David Schmenk  wrote:
>> Tom Greene wrote:
>>> On Aug 29, 12:59 am, David Schmenk
 wrote:
>>>> Thanks again to Tom for trying this out.  Maybe I can
convince him to
>>>> try this one out:
>>>> http://schmenk.is-a-geek.com/tarfiles/VM02ALPHA3.DSK.zip
>>>> I also discovered a couple of other issues now fixed.  Certain ROM
>>>> routines will disable interrupts.  Some of my sample
classes that call
>>>> ROM routines for low res and hi res graphics all of the
sudden stopped
>>>> responding to interrupts.  I now re-enable interrupts
after every native
>>>> method.  I also discovered that my comparison opcodes
would adjust the
>>>> stack pointer, then compare the values that were now above
the stack.
>>>> Tsk, tsk.  When an interrupt would occur during the comparison, the
>>>> values would get trashed.
>>>> Glen Bredon wrote a nifty little TSR style program that
would hook the
>>>> VBL interrupt to keep time.  His notes mentioned problems
with various
>>>> IIc models.  He actually didn't bother calling the mouse firmware to
>>>> service the interrupt on a IIc.  The VBL interrupt would continue
>>>> interrupting anyway.  So I now look to see if any hardware
claimed the
>>>> interrupt.  If not, I assume it's the VBL interrupt.  Hope
this works,
>>>> Dave...
>>> Sure thing... alas I didn't get any better results, it still runs fine
>>> on the IIc+ but freezes on the other two ROMs.
>>> One thing I notice with both versions is that keyboard input seems to
>>> extend the run time a bit. That is to say, if I start the helloworld
>>> program and just let it run without touching anything, it runs for
>>> about 30 seconds before freezing. If I start the program and then
>>> pound on the keyboard continuously, it runs about 35 to 40 seconds.
>>> Tom
>> Hi Tom-
>>
>> Last time you said it continued to buzz after it stopped responding.
>> Does it still do this?  I thought I caught all cases, unless the mouse
>> firmware is lying about about the VBL interupt source.  Thanks,
>>
>> Dave...
> 
> Yes, the buzz continues. I take it you haven't had this happen on your
> own machines?
> 
> Tom

My IIc and II+ run all day.  The good news is the VBL is still active. 
I'll work up a scenario to catch it.  Thanks for the great feedback.

Dave...
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