SECAM Colecovision

[Spitfire]

I found a SECAM Colecovision at a fleamarket recently, and since it was an absolute steal I got it. The interesting thing about it is that it has an RGB (SCART) rather than an RF output. But, of course, my problem is now that I only have a PAL/NTSC/NTSC-J TV, which makes the console all but useless for me. No big deal, I have a PAL CV as well, but the RGB output should give a better picture quality...

So - since the SECAM CV has the same video chip as the PAL version, I was wondering if it's possible to modify it to work on a PAL TV?

[Mayhem]

It'll work fine on a PAL standard TV... as long as the TV has a Scart socket! Which I presume most in the US don't... it's mainly a Europe only device. What input connections does your TV in question have?

[chadtower]

That's awesome! I'd love to acquire that if you end up parting with it.

[sniperCCJVQ]

Work fine on the US console too (i presume).

Because i find a SMURF last summer and it was SECAM.

[Zaxxon]

How could it output RGB? I think that's impossible unless the SECAM CV uses the version of the TI graphics chip used in the TI99. The TI chip used in the USA CV cannot output RGB.

[opcode]

The TI chip used in the USA CV cannot output RGB.

That isn't enterely true. The CV TI chip does feature RGB output. The problem is the necessary output circuitry wasn't implemented. I have a RGB moded CV, and the image is very cool. :)

Eduardo

[Zaxxon]

How do you mod a CV for RGB output?

[Spitfire]

Zaxxon:


How do you mod a CV for RGB output?

Like-a this-a: http://www.a1k0n.net/projects/coleco/

Mayhem:


It'll work fine on a PAL standard TV... as long as the TV has a Scart socket! Which I presume most in the US don't... it's mainly a Europe only device. What input connections does your TV in question have?

Well, its a new-ish Sony PAL TV with 2x Scart and 1x RGB on the front panel. If I connect the CV on one of the Scart sockets, the TV flickers and switches into "not happy" mode, i.e. blank screen. Sound's okay, though.

Any thoughts?

[Mayhem]

I presume you've tried both Scart sockets? Looks like you lucked out and got RGB compatibility through this front connector (how many sockets btw?) and not either of the two Scarts! :roll:

[Zaxxon]

Zaxxon:


How do you mod a CV for RGB output?

Like-a this-a: http://www.a1k0n.net/projects/coleco/



That's not an RGB mod. That's just an A/V composite video mod. I already have a CV like that. I don't know if that's what opcode was thinking too. From what I've read on those chips and in TI's own docs, there isn't a way to get RGB output from the CV video chip. S-video and composite, yes.

[opcode]

That's not an RGB mod. That's just an A/V composite video mod. I already have a CV like that. I don't know if that's what opcode was thinking too. From what I've read on those chips and in TI's own docs, there isn't a way to get RGB output from the CV video chip. S-video and composite, yes.

The TMS9918 manual says:

"The TMS9928A/9929A [note: used with the CV] are functionally identical to the TMS9918A except that the NTSC color encoding circuitry has been removed and replaced with luminance and color difference signals. The TMS9918A is pin-for-pin compatible with the TMS9928A/9929A, except for three pins, the composite video output, the external video input and the CPU clock output. These pins are replaced with the Black/White luminance and composite sync (Y) outuput and two color difference pins, Blue (B-Y) an Red (R-Y) outputs, respectively. The color difference outputs allow the user to generate Red-Gree-Blue (R-G-B) drive for direct color gun control, or composite video for use with NTSC or PAL video color monitor. However, to connect these three outputs to a R-G-B or monitor requires additional R-G-B or encoder circuitry."

Here is Brazil there was a MSX computer called Expert. That machine used the same VDP as the CV and featured both composite video and RGB. So I just "removed" the RGB circuitry from an Expert and placed it inside a CV. The resulting image is just stunning. :)

Eduardo