{"id":1049,"date":"2020-08-14T16:41:58","date_gmt":"2020-08-14T14:41:58","guid":{"rendered":"https:\/\/retrofixes.it\/?p=1049"},"modified":"2023-03-28T09:21:21","modified_gmt":"2023-03-28T07:21:21","slug":"trs-80-coco2-composite","status":"publish","type":"post","link":"https:\/\/retrofixer.it\/en\/trs-80-coco2-composite\/","title":{"rendered":"Tandy CoCo2 Composite mod"},"content":{"rendered":"
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Here is another computer that has only an RF video output, already today it is a big limitation but at the time there were not many who had a dedicated monitor at home and it was much easier to connect the computer or the console to the TV. Now that the analog RF signal has fallen into disuse, it is increasingly difficult to find a device capable of handling it. Besides the problems in finding a tv or decoder to use this signal, as we know, the quality of this is quite low.<\/p>

I have not found much on this model on the net, there is a lot on the TRS-80, the 2-3 American color computers, all with the NTSC standard. And who has a PAL model for?<\/p>

On the net I have not found a schematic of my card, the most similar ones still have different chip numbering and with different ram modules, while in my card there are only two. I did not give up and turning on forums etc. I saw that someone said it was a modification like the Atari 2600 even if often the first model of TRS80 came out and not the COCO 2.<\/p>

Well, in the meantime I started removing the RF modulator to actually see the pins and their functions\u2026 Bingo! the pins are simply a + 5V, Audio, a channel selector (not fitted to my model) and a composite signal!<\/p>

If you also have this card model you can follow the following guide.<\/p>

Step 1: Let's open the computer<\/h3>
The first thing to do is obviously remove the screws on the back in order to open the computer, there are 6 screws in total and the top comes off without problems. Inside we find the keyboard connected with a membrane cable, to be disconnected by force on the membrane right where the connector is, do not pull from very high to avoid damaging the flat.<\/div>
It is then necessary to remove 4 screws and a power connector to free the motherboard, under it there is a cardboard shield to remove.<\/div>
\u00a0<\/div>

Step 2: We disconnect the modulator<\/h3>

Now arm yourself with patience and a good soldering iron to heat up, because the modulator casing is soldered on the ground tracks and 2 tabs must be straightened in order to remove the block. It took me at least 15 minutes to remove all the tin with a blower and desoldering braid (here the desoldering iron was not useful) to be able to safely release the modulator. Be careful because if you haven't removed all the tin (the pcb is double-sided !!) you risk blowing up some tracks.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t

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Step 3: We connect the composite output<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t
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Here you can see the order of the signals on the board, starting from the right we find the composite sensor, the 5Volt, the CH3-4 selector, and the audio.<\/div>\n
The mass can be taken in different points, even on the same slots where the modulator was mounted.<\/div>\n
For the modification I used the one I use for the Atari2600 and below I put the diagram.<\/div>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
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Step 4: Finish<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t
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Now all that remains is to bring out the RCA connectors for the audio and video connection.<\/p>

Removing the modulator you have a hole to be able to put the video RCA but the audio? well, right next to it is the channel selector that was not used or if the switch is mounted, just remove it.<\/p>

I don't want to ruin the case by drilling holes etc. I preferred to print an adapter with the 3D printer so that I could put the connectors in an easy and non-invasive way.<\/p>

In this way it is possible to remove everything and reassemble the modulator bringing the computer to its original state without any sign.<\/p>

Now close everything and enjoy the CoCo with a composite signal !.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<\/div>","protected":false},"excerpt":{"rendered":"

Let's see how to get the composite signal out of the PAL version Tandy Color Computer 2.<\/p>","protected":false},"author":1,"featured_media":1056,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[19,75],"tags":[71,73,74,31,72,70],"class_list":["post-1049","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-computer","category-tandy","tag-coco2","tag-color-computer","tag-composito","tag-mod","tag-tandy","tag-trs-80"],"_links":{"self":[{"href":"https:\/\/retrofixer.it\/en\/wp-json\/wp\/v2\/posts\/1049","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/retrofixer.it\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/retrofixer.it\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/retrofixer.it\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/retrofixer.it\/en\/wp-json\/wp\/v2\/comments?post=1049"}],"version-history":[{"count":0,"href":"https:\/\/retrofixer.it\/en\/wp-json\/wp\/v2\/posts\/1049\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/retrofixer.it\/en\/wp-json\/wp\/v2\/media\/1056"}],"wp:attachment":[{"href":"https:\/\/retrofixer.it\/en\/wp-json\/wp\/v2\/media?parent=1049"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/retrofixer.it\/en\/wp-json\/wp\/v2\/categories?post=1049"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/retrofixer.it\/en\/wp-json\/wp\/v2\/tags?post=1049"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}