Old CRT tv to simple monitor - Page 1
Forum section: electronics / projects

author: MrZwing
author_rank: Regular Contributor
timestamp: April 09, 2016, 08:05:15 pm
content: Hello I'm one of those nostalgic retro computer guy's that like the old BASIC computers.i also plan to build a old computer called ABC 80 . (a Swedish retro classic based off a Z80).But i want to build a replica CRT as well and wonder how you would go about Rebuilding an old CRT Tv to a proper old basic computer monitor.That means i want to just connect it straight into the tv without the hassle of fiddling with channel searches or having to change channels just simple plugg 'n play.is it doable? i don't care if it's a hassle and such i just want to do it for fun, i will experiment on old computer monitors as well but tv's are easier to find in secondhand shop's cheaper then a monitor.MrZ

author: Kleinstein
author_rank: Super Contributor
timestamp: April 09, 2016, 08:19:23 pm
content: For very old computers with low resolution this can work. The main thing is that the horizontal frequency has to be reasonably close - the typical TVs don't have much freedom there. So old computers that are meant to work with a TV via a HF modulator are usually OK.It's relatively easy it it has a SCART input - in this case the chassis is also isolated from mains and not one of the old ones with a life chassis. Stay away from those very old ones (e.g. before 1980s).The Scart input can usually get direct input of video signals. But not every TV accepts every type (e.g. FBAS, RGB or brigtness / color separate).

author: MrZwing
author_rank: Regular Contributor
timestamp: April 09, 2016, 08:31:58 pm
content: hmm how safe are old portable tv's?but i will take that advice and avoid old 70's tv's and keep på 1980+ vintage.what will i have to do to bypass the whole "channel select/scan" deal since i would like to just plug it in and be done with the hookup.well if i can i will try to get my hands on some really old computer monitors (have a friend that is drowning in them so i might be able to "borrow" 2-3 from him)

author: ChristofferB
author_rank: Frequent Contributor
timestamp: April 09, 2016, 08:35:51 pm
content: Old CCTV monitors are great, if you can find them. They're composite in, and usually pretty small.Newer CRT based CCTV monitors might be viable as well. If you have a CRT oscilloscope, you could mod that to accept composite video as well, I've seen. Dunno how well that works.-I've seen the ABC-80, I think it had a bit of success in Denmark as well.

author: MrZwing
author_rank: Regular Contributor
timestamp: April 09, 2016, 09:23:29 pm
content: A CCTV would work nicely for the "laptop" edition, and if i can find a CRT monitor like that it would makes things a lot simpler indeed.think it was distributed around the Nordic countries, but yeah got some minor memories of the ABC 80 played space invaders on it at a friend of my father. but i want one.

author: Kleinstein
author_rank: Super Contributor
timestamp: April 09, 2016, 10:52:32 pm
content: If you get a TV with scart connector, it's mainly down to making an adapter cable: have the signal at the right input and have a signaling voltage / jumper to show the TV that this input should be used. So the TV set can be unmodified and this would also work with most modern LCD TVs.Having a modern TV with isolated chassis should be reasonable safe. It was Ok in the 1990s to have things like a VCR connected. If in doubt have the computer earthed.

author: MrZwing
author_rank: Regular Contributor
timestamp: April 10, 2016, 04:37:46 pm
content: Hmm i will read up on it and keep earthing in mind don'f feel lika a electrical boost to my synapses.

author: Raj
author_rank: Frequent Contributor
timestamp: May 13, 2016, 07:23:41 am
content: here's a schematic of (untested [gonna test it very soon] ) vga to composit