repetto74 Posted March 26, 2018 Share Posted March 26, 2018 Hi Guys, I have successfully built a fairly simple composite mod for the COCO 1 here : http://www.cocopedia.com/wiki/index.php/File:Trs80coco2compmod.gif This works pretty good and I can have a very decent composite picture over an LCD screen. Now I am wondering how to perform a composite mod on a COCO 2? As far as I read over the net this COCO1 mod is not compatible with the COCO 2 (a close look at the Coco2 MB reveals that there is no video encoder chip MC1372). Is there any DIY alternative? Here is a picture of the RF modulator on my COCO 2. Thanks Rick Quote Link to comment Share on other sites More sharing options...
R.Cade Posted March 26, 2018 Share Posted March 26, 2018 Looks like you have to add a board with that chip... https://sites.google.com/site/thezippsterzone/home/coco2-projects/coco-2-composite-board-1 Quote Link to comment Share on other sites More sharing options...
repetto74 Posted March 26, 2018 Author Share Posted March 26, 2018 Hi R.Cade, Ok sounds interesting but is the project free or is this something I will have to buy? I am looking for a free project I could build myself :-) Quote Link to comment Share on other sites More sharing options...
R.Cade Posted March 26, 2018 Share Posted March 26, 2018 Schematics are on that page... Quote Link to comment Share on other sites More sharing options...
repetto74 Posted March 26, 2018 Author Share Posted March 26, 2018 (edited) Well difficult to read out this schematic image. Wondering just if the whole project was available to print out the circuit board. I do see also that this is apparently for NTSC COCO's while mine is a PAL version.Thanks anyway! :-) Edited March 26, 2018 by repetto74 Quote Link to comment Share on other sites More sharing options...
jmdlcar Posted June 11, 2018 Share Posted June 11, 2018 Well difficult to read out this schematic image. Wondering just if the whole project was available to print out the circuit board. I do see also that this is apparently for NTSC COCO's while mine is a PAL version.Thanks anyway! :-) I found this for the Coco2 it is CoCo2 Composite and Sound board. It looks easy to install and it is $30.00 http://www.cocowares.com/item.php?nombre=CoCo2%20Composite%20and%20Sound%20board Quote Link to comment Share on other sites More sharing options...
ColorComputerStore Posted June 26, 2018 Share Posted June 26, 2018 CoCo 1 and 2 both use MC1372. Is your machine PAL? Quote Link to comment Share on other sites More sharing options...
jmdlcar Posted June 27, 2018 Share Posted June 27, 2018 CoCo 1 and 2 both use MC1372. Is your machine PAL? Who are you talking to, if me I don't know. How can I tell what it is? Quote Link to comment Share on other sites More sharing options...
ColorComputerStore Posted June 27, 2018 Share Posted June 27, 2018 Download the Color Computer Technical Service manual. Then look at the pages of NTSC vs PAL schematics and match it up with what you have. Quote Link to comment Share on other sites More sharing options...
jmdlcar Posted June 28, 2018 Share Posted June 28, 2018 (edited) My eyes are not very good anymore so if you can tell what I am looking for. My Coco 2 is a 16k model 26-3027 as far as I know it was sold in the USA. If it mean anything my 6847 chip is U8. I don't have a PAL schematics Edited June 28, 2018 by jmdlcar Quote Link to comment Share on other sites More sharing options...
ColorComputerStore Posted May 23, 2019 Share Posted May 23, 2019 If your CoCo was bought in the USA, then it is NTSC, not PAL. I would recommend CoCoVGA to get a VGA signal from your CoCo 2. Quote Link to comment Share on other sites More sharing options...
trossin Posted January 30, 2021 Share Posted January 30, 2021 You can find a clear version of the schematic below. It seems like a direct copy with different transistors specified. I don't know who was first but at least I was able to get the two resistor values on the base of the PNP transistor from the diagram on this page: https://pmig96.wordpress.com/2020/07/27/mc6847-test-circuit-part-4/ Quote Link to comment Share on other sites More sharing options...
trossin Posted February 2, 2021 Share Posted February 2, 2021 Ok the source of the schematic is from Moto in the 6847 data sheet: https://colorcomputerarchive.com/repo/Documents/Datasheets/MC6847 MOS Video Display Generator (Motorola).pdf on the bottom of page 12 figure 15 Quote Link to comment Share on other sites More sharing options...
MrDave Posted February 3, 2021 Share Posted February 3, 2021 Here was my solution for a coco that has no rf or 1372 circuit..very simple solution .. Quote Link to comment Share on other sites More sharing options...
Green3 Posted May 19, 2023 Share Posted May 19, 2023 Radio Shack's Color Computer Technical Bulletin #27 talked about this. I've uploaded those specific pages here. CCTB27.pdf Quote Link to comment Share on other sites More sharing options...
Like us on Facebook
Follow us on Twitter
AtariAge on Instagram
Watch us on YouTube
Chat on Discord
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.