[comp.sys.ibm.pc] HD interferes with ATI VGA

fordke@ingr.com (Keith Ford x8614) (07/10/90)

I just put together a Jameco 80386-20.  It has an ATI VGA1024 video
card, Seagate ST277R-1 RLL hard drive, and an Adaptec (2732B?) hard/
floppy controller.  The problem is anytime there is a lot of disk
activity, like boot up, the video gets messed up.  Looks like stray
RF.  I've narrowed it down to the card by swapping it with an older
VGA Wonder I had.  I'm curious if anyone has had this problem and
found a solution.  Any leads would be appreciated.  Keith Ford.
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granroth@iowasp.physics.uiowa.edu (07/11/90)

In article <11438@ingr.com>, fordke@ingr.com (Keith Ford x8614) writes:
> I just put together a Jameco 80386-20.  It has an ATI VGA1024 video
> card, Seagate ST277R-1 RLL hard drive, and an Adaptec (2732B?) hard/
> floppy controller.  The problem is anytime there is a lot of disk
> activity, like boot up, the video gets messed up.  Looks like stray
> RF.  I've narrowed it down to the card by swapping it with an older
> VGA Wonder I had.  I'm curious if anyone has had this problem and
> found a solution.  Any leads would be appreciated.  Keith Ford.

Hmmm . . . I had noticed video interference during disk activity on
several of our Gateway 2000 systems with the ATI VGA and ESDI cached
controllers.  I haven't taken the time to give Gateway a call about
this yet, but it sounds like the same problem.  (The interference is
definitely noticeable, but not considered serious by the users.)

-Larry    Granroth@IowaSP.physics.UIowa.edu    IOWASP::GRANROTH

nadkarni@ashok.nac.dec.com (ashok p. nadkarni) (07/11/90)

This information is second hand from a friend. It seems some of the ATI
VGA Wonder cards
shipped had a faulty SN74LS241N chip on board. Any kind of power supply
noise or fluctuation
(as when you access the hard disk), causes problems in the video
display. The ATI boards have
a WU or WC prefix (I'm not too sure about this). 

Sorry don;t have any more info. The machine my friend had was from
Gateway but I imagine the same problem could exist in any ATI card.  If
you bought the machine from Gateway, give them a call. If you put it
together yourself, you might want to give ATI a call. Let us know what happens.
I have a ATI VGA myself though I have not seen this problem.

/Ashok