Re: Apple IIc going crazy, bad ROMs ?

[dempson@actrix.gen.nz (David Empson)]

Gabriele72 <Arel72togli_questa_parte@email.it> wrote:

> Silicon Sam ha scritto:
> 
> >   Sounds like bad RAM to me....  It's far more common for the RAM to
> > fail than the ROMs.  There is a built-in RAM test, try resetting it
> > with CTRL-Open Apple-RESET or CTRL-Closed Apple-RESET.  Or CTRL-both
> > Apple keys-RESET does it with sound.  It's been far too long, but I
> > think that's it.
> 
> Unfortunately the RAM ICs are soldered to the mainboard so I cannot 
> quick-test them. However, when pressing CTRL+RESET+both apples a routine
> starts... but I get a blocky screen always changing every 2 seconds 
> while I hear the computer tick. It never ends, although it seems to me
> that the patterns are periodic. Nothing readable anyway.

That sounds like you have a //c with the original firmware. It doesn't
have a proper self test, just that lo-res graphics pattern screen which
I am not aware of ever having produced any useful test results.

The revised firmware (with UniDisk 3.5 support) added a proper self
test, including a basic RAM test, similar to the one in the IIe.

-- 
David Empson
dempson@actrix.gen.nz