Tandy 1000A Composite Video in Color

[Trixter]

A sony trinitron CRT should produce color for composite color games/modes. One way to test composite color output is to grab cga_comp and run its composite monitor tests, specifically "Composite Monitor Tests -> Composite: Low-res Graphics". If that doesn't produce color, then your composite color output is broken.

However, the Tandy series produce composite color with the hue 180 degrees rotated from CGA. So, the colors are wrong. The only game I know of that has correct color output in composite mode is Blue Angels, as that game was tested on a Tandy (and as a result the colors are incorrect on real CGA).

 

[genocho]

A sony trinitron CRT should produce color for composite color games/modes. One way to test composite color output is to grab cga_comp and run its composite monitor tests, specifically "Composite Monitor Tests -> Composite: Low-res Graphics". If that doesn't produce color, then your composite color output is broken.

However, the Tandy series produce composite color with the hue 180 degrees rotated from CGA. So, the colors are wrong. The only game I know of that has correct color output in composite mode is Blue Angels, as that game was tested on a Tandy (and as a result the colors are incorrect on real CGA).

Hi,

I tested cga_comp and still monochrome, but have to say I tried my tandy on a lcd tv and if I move a bit the jack on the tv can see for a fraction colors, so i guess i need a compatible monitor / tv for it. Still think those tsr´s for color burst can do the trick for me. Hope someone can reupload them.
I´m gonna try with a pc tv capture card, maybe will catch this picky ntsc composite signal. Anyways tandy works perfect on the db-9 (rgb) output, so i dont think the composite part of my tandy is broken. I noticed there is a cap solder on the video output on the pcb. Can be a bad cap problem causing this issue ??? Anyone knows if it´s avalaible the schematic of the tandy 1000 ???

Regards.

 

[Trixter]

Still think those tsr´s for color burst can do the trick for me.

CGA_COMP turns on colorburst, so if it isn't working, no TSR will.

tandy works perfect on the db-9 (rgb) output, so i dont think the composite part of my tandy is broken

That isn't logical. Of course one could be broken and not the other.

Can be a bad cap problem causing this issue ??? Anyone knows if it´s avalaible the schematic of the tandy 1000 ???

ftp://ftp.oldskool.org/pub/drivers/Tandy/Tandy_1000_Technical_Reference_Manual.pdf

 

[genocho]

CGA_COMP turns on colorburst, so if it isn't working, no TSR will.



That isn't logical. Of course one could be broken and not the other.



ftp://ftp.oldskool.org/pub/drivers/Tandy/Tandy_1000_Technical_Reference_Manual.pdf

Hi,

Well, it´s hard to beleive if something is wrong with the composite part, the rgb part works.
I mean, what can be wrong in the color burst part, i can only see a transistor, a 74ls244 and resistors. If any of this components are wrong dont think even show monochrome image.
In the page 489 of the manual i can noticed the video chip have a compositevideo pin, and this pin goes straight to a 74ls244, then resistors and a transistor.





Guess iam gonna change all and try if something change.
I assume the video chip is ok, thats why i say if i have tandy with rgb, must be something in the composite side, but really strange.


Regards.