[Coco] CoCo 3 RGB to CGA conversion

[Mike Pepe]

Do you mean CM-8? The CM-10 is a digital RGB monitor for PC-clones

The CM-8 is (was?) an analog RGB monitor. The IBM one is Digital RGB.
You can use it but as you noticed the colors will be wrong.

Fixing this requires fairly extensive knowledge of how the IBM monitor
works internally (schematics, service manual, etc) to convert it into an
analog monitor.

Recommendation would be to get one of the CoCo3 to VGA adapters and use
a VGA monitor. Finding an analog RGB monitor these days is really quite
the challenge.

> -----Original Message-----
> From: coco-bounces at maltedmedia.com [mailto:coco-
> bounces at maltedmedia.com] On Behalf Of N8WQ
> Sent: Saturday, March 14, 2009 4:18 PM
> To: CoCoList for Color Computer Enthusiasts
> Subject: [Coco] CoCo 3 RGB to CGA conversion
> 
> Fellow CoCo users,
> Last night my faithful CM-10 monitor let out some smoke (if you know
> what I mean, LOL). The only other monitor I had laying around was my
> IBM
> 5153 CGA Color Monitor. I plugged it into my homebrew CoCo tower and I
> have video but the colors are off. I compared the pin assignments on
> the
> IBM monitor to the CoCo 3 RGB outputs and all pins are the same except
> pins 6 and 7.
> 
> On my CoCo tower I wired up a DB9 connector to plug my CM-10 into.
> 
> IBM 5153             CoCo 3 RGB connector
> ---------------       ---------------
> pin 6 = Intensity     pin 6 = Polarity
> pin 7 = Reserved   pin 7 = Sound
> 
> So I need to remove wire to pin 7. What should I do about pin 6?
> 
> H-freq is 15.75 khz, and V-freq is 60 hz on the 5153 monitor.
> 
> Alan Jones
> 
> --
> N8WQ - Canal Winchester, Ohio
> http://exwn8jef.googlepages.com/home
> 
> 
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