Re: broken double hires

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

100041.1464 <100041.1464@CompuServe.COM> wrote:

> Which parts of my Platinum //e are responsible for the double 
> hires graphics?

The IOU chip is responsible for all video modes, with some help from
external hardware.

> It's not working anymore. Yesterday (maybe last month) double 
> hires was running fine, now the screen is missing the half of the 
> pixels.

Exactly which pixels are missing?  Are they disappearing in groups of
seven horizontally, is every second pixel missing, or what?

What exactly do you mean by "missing"?  Are the "missing" pixels just
black?

Another possibile interpretation is that the screen is not going into
double hi-res graphics mode at all, so you only see half of them (in
groups of seven).

Depending on the exact symptoms, it might be a component external to the
IOU.  Otherwise, you will have to replace the IOU to get it to work
again.

-- 
David Empson
dempson@actrix.gen.nz
Snail Mail: P.O. Box 27-103, Wellington, New Zealand