Workaround to Interface CM-5 Monitor to COCO 3 VID-OUT

[Knuckledragger]

Obviously I am new to your forum; better still, I am new-old to a forum period. I found you guys accidentally a few days ago while doing my best to refrain from pulling my teeth out due to frustration; I was searching for some help for a COCO 3 when I basically stumbled over your now ancient post on interfacing a Model I to a TV. After calming myself by settling back with a pack of menthol coffin nails and a brew I took the time to read all of the replies on that original post; I knew then and there that perhaps I had found the right place, whether it be by pure chance or maybe the long gone but not for gotten Tandy Gods knew my sorrows and took pity upon this poor soul enough to steer me towards you through divine intervention.
Thus my question; does anyone possibly know if it is possible to do a workaround to interface a CM-5 monitor to allow a connection to the RGB VIDEO-OUT on a COCO 3? After studying the PIN-OUTS on both monitors I have some ideas; however, as Led Zeppelin said, “Its Been A Long Time Since I Rock-and-Rolled”, and in my case attempted to perhaps electrocute myself or explode a CRT monitor screen up in my face due to total stupidity or a bad case of brain gas.
At this point I will stow my pie hole and humbly await a hopeful response to my tentative project.
Thanks in advance and best wishes to all.

 

[ahm]

does anyone possibly know if it is possible to do a workaround to interface a CM-5 monitor to allow a connection to the RGB VIDEO-OUT on a COCO 3?

It looks to me like the COCO 3 has a "RF Out" jack (TV signal) and a "Video" (composite video) jack. And the Tandy CM-5 monitor appears to be a CGA monitor.
I don't know of an easy way to connect the two.

Instead, I'd use a small TV with an adapter for the antenna jack (RCA female to "F" male, Radio Shack #278-255) and a video cable with RCA male plugs on both ends, to the "RF Out".
Or if you have a monitor that takes composite video input, use that instead (without the adapter) to the "Video" jack. Picture quality will be better than the TV.

 

[dabone]

Coco3 has a rgb out on the under side. It's a pin header.

The coco3 is analog rgb is is compatible with the CM-8 monitor, or people have interfaced it with amiga monitors also.

It's a 15k analog rgb.

Pin outs are here.

http://pinouts.ru/all/Cm8CoCoRGB_pinout.shtml

Premade cables for a few type of monitors are here.

http://www.frontiernet.net/~mmarlette/Cloud-9/Hardware/Video%20Cables.html

I use a homemade adapter with a Nec AccuSync LCD 71V. it's one of the very few lcd monitors I've seen that can accept 15k

Later,
dabone

 

[GottaLottaStuff]

Where are you located? It might be easiest just to swap monitors with someone close by.

 

[Eudimorphodon]

I use a homemade adapter with a Nec AccuSync LCD 71V. it's one of the very few lcd monitors I've seen that can accept 15k

Interesting, because it looks as if the manual for that monitor claims its sync range only goes down to 31k. I wonder if other similar vintage NECs can also handle less-than-VGA frequencies. (I have an NEC 2080UX, and now I also have a devious TTL-to-VGA conversion plan.)

 

[dabone]

Interesting, because it looks as if the manual for that monitor claims its sync range only goes down to 31k. I wonder if other similar vintage NECs can also handle less-than-VGA frequencies. (I have an NEC 2080UX, and now I also have a devious TTL-to-VGA conversion plan.)

I was playing with groovymame and forgot to change to the standard mame when I had the pc hooked up to a regular monitor and noticed that it was still working. It was blind luck that I discovered that it worked. PAL modes don't. They display, but cut off a good portion of the picture. I also have a old corena 19" LCD tv that does work with pal RGB signals over the vga port, but it's always looked like crap.

The Coco3 looks ok, and the c128 is readable with a simple resistor/diode ttl converter, I'm wanting a better solution and someone over at 128alive is getting some made.

Later,
dabone