[comp.sys.amiga] Amiga Chip problem?

178504488@excalibur.UUCP (03/03/87)

	I just started using an Amiga at Villanova University.  Although
I was supposed to be doing some development on Mult-Forth I had the urge
to use Flight Sim II.  So I booted up only to come up with a picture of
a run way intermittently covered by static, with static covering up even
the engine sound.  This was by no means analog static or interference, but
"digital static" as in static literally being drawn unto Video and Audio 
Ram locations.  It seemed that maybe the blitter was corrupting the data
it was redrawing since pictures started going all over the place as the static
eventually took over the entire screen and crashed the Amiga.  I tried
games such as Artic Fox, One-on-One, Marble Madness (the wave section)
with similar results.  However, non-animated games such as Chessmaster 2000
showed know problem.  I tried the line drawing on Aegis Draw and the shaded
circles and rectangles in Deluxe Paint with no problem.  Also I took note
that there was no problem whatsoever with window manipulation and all graphic
demos (Boing, Ray Juggler, Lines, Dots, Rect, ect.).  Another interesting
fact to stirr things up was that Flight Sim II only uses the 68000 for 
animation.
	Maybe its the sound chips?  No, Speech works and so does Instant
Music-- at least until I start drawing the first line off notes.  So whats
going on!  The CPU is dated October 85.

			Wilson Cheung

wtm@neoucom.UUCP (03/05/87)

Your Amiga going nuts with Flightsim II sounds very similar to what
happened to me about a year ago just a couple of months after I got
my Amiga.  For the last year, it has purred along quite happily
(knock on wood).

What happend to me only (or at least primarily) showed up when
running Amiga (microsoft) Basic.  The music demo program was the
killer.  It would run for about 2 to 5 minutes and then all heck
would break loose, with the most bizarre sounds you've heard coming
out, and some really wild looking video that I can't really
describe.  It turned out that Basic uses some interrupt mode
particularly heavily that brought Agnus to its knees.

The bad part (that's a play on words, son) is that it took 3 new
Agnuses (Agni ??) to get the machine working again.  It wasn't
completely terrible, as the whole mess was covered under warranty.
I still wound up paying about $25 in gasoline and lots of lost time
as the local dealer is about 45 min. away.

With all the reported problems with Flightsim lately, it sounds
like its a good program to have around to smoke out marginal
hardware.

  --Bill

ee173way@sdcc3.ucsd.EDU (John Schultz) (03/05/87)

  Sounds like another case of a bad 256k ram cartridge.  Try
replacing it first, as it is the easiest possible hardware fix.

  John
  7OHN