Amiga 1000 composite video output (colour?)

[vimfuego]

Hi All,

I recently got a few A1000's, just going over them and some have colour on the single RCA composite output whilst others are only B/W.
I didn't think any of the early Amiga's had colour output unless you had an A520 plugged in and used its output.
So I guess my questions are, did the A1000 have colour output on the RCA video output and I just have a few faulty ones (B/W)? Or might have someone modified them for colour output on the RCA connector?

TIA

[T_hairy_bootson]

All the ones I have/had do colour composite.

[ajk]

The A1000 uses a colour TV encoder chip, whereas the A500 have a Commodore video hybrid board that only provides monochrome output. Not sure if there are different versions of the A1000 in that regard though.

[Toni Wilen]

Some early PAL models (I guess original models with daughterboard only) can have PAL Agnus but NTSC configured video encoder (MC1377 pin 20 grounded = NTSC mode + NTSC external components) and NTSC main clock crystal. (PAL=28.37516MHz, NTSC=28.63636MHz, inside the metal box)

[vimfuego]

Ok thanks, I think I'll assume the B&W ones have an issue then. Cheers

[vimfuego]

A little more on this, I pulled the lid off to start looking around the video output circuits.
The datasheet for the MC1377P chip says ground pin 20 for NTSC, open for PAL. Well on my PCB there is no jumper, Pin 20 just goes direct to GND, there is no provision for a jumper on the PCB.
Looking at the PCB images on Amiga Hardware Database it looks like this one is an NTSC PCB, even though on the back it says "PAL' so dunno what the go is now.

[quarkx]

Ok, So I could be wrong, because I never used it, and it could be different for PAL, but I always thought you needed one of these for color out.

[Toni Wilen]

Originally Posted by vimfuego

Looking at the PCB images on Amiga Hardware Database it looks like this one is an NTSC PCB, even though on the back it says "PAL' so dunno what the go is now.

I guess early PAL models are NTSC models with NTSC Agnus replaced with PAL version (and region matching PSU too)

Check also main crystal frequency (under the metal box)

Originally Posted by quarkx

Ok, So I could be wrong, because I never used it, and it could be different for PAL, but I always thought you needed one of these for color out.

All A1000s have color composite video output, unfortunately A500 RCA video output is B&W only.

Device in your image RF modulator, Amiga to TV antenna cable adapter. (Which has even worse quality than composite)

[idrougge]

Originally Posted by Toni Wilen

I guess early PAL models are NTSC models with NTSC Agnus replaced with PAL version (and region matching PSU too)

That is correct. Early PAL A1000 models have only the most basic modifications required for colour composite output. They still use an NTSC main crystal (which makes them slightly faster than proper PAL A1000s), so the composite video is not really PAL conformant, genlocking is not possible and video quality (on composite) is generally shitty, perhaps so shitty that your monitor/TV won't recognise it as a colour signal at all.

There are instructions on how to modify the A1000 to give a more conformant PAL signal, and later machines (at least from 1987 onwards) do support proper PAL output.

[qq1975b]

Originally Posted by idrougge

That is correct. Early PAL A1000 models have only the most basic modifications required for colour composite output. They still use an NTSC main crystal (which makes them slightly faster than proper PAL A1000s), so the composite video is not really PAL conformant, genlocking is not possible and video quality (on composite) is generally shitty, perhaps so shitty that your monitor/TV won't recognise it as a colour signal at all.

There are instructions on how to modify the A1000 to give a more conformant PAL signal, and later machines (at least from 1987 onwards) do support proper PAL output.

Hi,

I have one of these early PAL A1000 with a daughterboard and a 28.6363 crystal. Could you tell me where I can find these instructions on how to modify the A1000 to give a more conformant PAL signal, please?

Thank you.

[qq1975b]

Is there anything else than replacing the crystal?

Thank you

[cbmeeks]

Just a note on my experience...I have a REV A board with the daughter card (NTSC). While diagnosing my machine, I hooked up composite and only get B/W (grey).

When hooking it up via S-Video, I get color (orange/red screen). I don't know if that's normal but mine is definitely not color from the composite.