[comp.sys.atari.st] Spectrum 512 and my machine...

long@sask.UUCP (Warren Long) (03/26/88)

I have discovered something very interesting about either my
machine or about Spectrum 512 (demo).  When I first turn on my ST
and display Spectrum images, it works perfectly.  After about 
5 minutes, the images start to flicker (only certain pixels).  After
more time (about 2 more minutes), more and more pixels have started
to flicker, eventually ending up with the whole image being a
flickering, indistinguishable mess.  It's a neat effect, but
undesired.

Why is this happening??  My guess is that somehow as my machine gets
warmer, something doesn't run as fast.  Anybody have any guesses as
to what is happenning??  (1 Meg. 520 ST, using colour TV).  Is my
memory dubious?  Is my video shifter about to die a painful death??

Thanks, Warren           (long@sask)

-- 
=-=-=-=-=-Warren Long at University of Saskatchewan, Canada-=-=-=-=-
Home: 78 Carleton Dr.,Saskatoon, Sasakatchewan, S7H 3N6
Phone: (306)-955-1237
=-=-=-=-=-U-Email: ...!ihnp4!alberta!sask!long     -=-=-=-=-=-=-=-=-

rich@lakesys.UUCP (Rich Dankert) (03/28/88)

In article <1072@sask.UUCP> long@sask.UUCP (Warren Long) writes:
>
>I have discovered something very interesting about either my
>machine or about Spectrum 512 (demo).  When I first turn on my ST
>and display Spectrum images, it works perfectly.  After about 
>5 minutes, the images start to flicker (only certain pixels).  After
>more time (about 2 more minutes), more and more pixels have started
>to flicker, eventually ending up with the whole image being a
>flickering, indistinguishable mess.  It's a neat effect, but
>undesired.
>
>Why is this happening?? 

	You either have a MMU chip failing or the GLUE chip failing after 
the system has been on for a fw minutes. I have never seen it act like this
but then its not out of the realm of possiblitys.

	Best way to check this out (if its thermal) wuold be to get a can 
of freeze spray from your local Radio Shack and simply freeze one or the 
other, and see what happens. Most likely the MMU though. just don't get too
crazy with the spray..........

rich
UUCP: {Ihnp4,uwvax}!uwmcsd1!lakesys!rich


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