Re: C16 related question

From: Marko Mäkelä (
Date: 2001-12-05 16:11:36

On Wed, 5 Dec 2001, Martijn van Buul wrote:

> Daniele Gratteri wrote:
> > Well, he said he has got a Commodore 16 that worked like a charm for many
> > years but now, when powered up, it shows only garbage on the screen, mainly
> > "@" chars.
> Seems like a stuck bit 0 to me. Wasn't screencode 0x01 '@', versus 0x00 ' ' ?

If you're thinking about space (screen code 0x20) versus @ (screen code
0x00), it would be bit 5 that is permanently zero.

> I'd hint for broken RAM.

Me too.  But it can also be outside of the screen area.  If a byte in the
stack area ($100-$1ff) is broken, any RTS or RTI instruction can fail
badly and crash the machine before the initialization is completed.


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