Re: Adding an external monitor to a Rev c CRT iMac?

Jamie Kahn Genet <jamiekg@[EMAIL PROTECTED]
> wrote:

> Jolly Roger <jollyroger@[EMAIL PROTECTED]
> wrote:
> 
> > In article <1ii2p4r.pcnab11p166hpN%jamiekg@[EMAIL PROTECTED]
>,
> >  jamiekg@[EMAIL PROTECTED]
 (Jamie Kahn Genet) wrote:
> > 
> > > Haha! I found an old Apple Multiple Scan 15av out back and it works
> > > GREAT! :-) Now I just need to find a decent LCD screen that will
work
> > > with the iMac's Rage Pro. What resolutions can the Rage Pro sup****t?
> > > ATI's site is useless.
> > 
> > You might have a look at http://everymac.com
or 
> > http://apple.com/sup****t/specs
> 
> Nah, they only tell me what resolutions the iMac can sup****t with it's
> built in monitor. In fact the Rage Pro sup****ts others as I can see
> after hooking up the external display.
> 
> Strange that a list of resolutions sup****ted by the Rage Pro should be
> so hard to find. Cheers anyway :-)

MacTracker doesn't know either.

1024x768 at 75 Hz will work fine.

A little back of the envelope calculation suggests that it can't go much
larger than that with only 6 MB of VRAM. It would need 3 MB of VRAM to
do millions of colours at 1024x768. 4.8 MB gets you to 1280x960, but it
wouldn't be able to manage 1680x1050 (typical 20" widescreen) without
dropping to thousands of colours.

The Rage Pro might reach its limit at a lower resolution, if it can't
handle the bandwidth. It can do 1024x768 at 75 Hz (58.98 Mpix/s), but
might not be able to keep up with 1280x960 at 60 Hz (73.73 Mpix/s).

There is also the question of whether it sup****ts the DDC mechanism for
identifying the video modes sup****ted by a connected monitor, or whether
it is hardwired to the capabilities of the internal display. What
options did it offer with the Multiscan 15AV?

-- 
David Empson
dempson@[EMAIL PROTECTED]