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Old MDA/Herc and CGA monitors

PostPosted: Fri Feb 20, 2015 9:32 am
by AlexC
OK, perhaps the 'old' in the title is redundant...

I'm looking for an amber/orange monochrome MDA/Hercules monitor to replace one that's dying. Currently attached to my Commodore PC10-III, the image has started changing size, which I think is a symptom of a dying flyback transformer. I don't have experience of fixing such things, and the 20,000V inside puts me off trying, so it's on death row. (unless anyone knows of someone who can repair such things?)

I know I could upgrade the machine to VGA, but I'm quite happy using it with text and Hercules graphics. It's nicely easy on the eye. So, is there anyone out there with such a monitor they'd be willing to part with? I'd consider a green phosphor one too.

Separately I'm also after a green monochrome CGA monitor for another XT machine.

Lower down the list, if anyone has a monochrome VGA (white phosphor) monitor I might be interested.

I live in Featherston, visit Wellington regularly and am willing to pay postage for items further afield.

Cheers,
Alex

Re: Old MDA/Herc and CGA monitors

PostPosted: Fri Feb 20, 2015 3:48 pm
by SpidersWeb
Something that'll be affordable and match your Commodore PC is a Commodore 1084S and a Commodore 128D CGA cable.
The 1084S was used with Amigas etc, so turns up on trademe quite often. These work perfectly as CGA displays, and you can buy the cables premade / brand new off ebay for cheap.

Just something to keep an eye out for. Finding CGA/MDA in NZ designed for PC use is a challenge - I've resorted to learning how to repair them, only finished one so far though.
If you get rid of your current screen, let me know, I'd buy it and attempt a repair - it could be a flyback, but much more likely to just be a bad capacitor or transistor.

Edit: although a 1084S in CGA mode isn't easy on the eye, you'd really want to stick with MDA for that, I just noticed your comments about preferring the Herc.
Edit2: oh and welcome to the forum! Glad to see another XT user.

Re: Old MDA/Herc and CGA monitors

PostPosted: Fri Feb 20, 2015 7:27 pm
by AlexC
Thanks, that's helpful. I do have a 1084S and I'd heard such things were possible. I'll check out those cables.

I really like the Herc for viewability. And that's important, for reasons I'll explain in a moment in the 'Introductions' area of this forum.

My first thought was a power capacitor in the Herc display, but online searches tell me the symptoms seem to check out with the flyback transformer (random spontaneous image resizing, at one point disappearing to nothing). Seems to vary somewhat according to heat, and only started a couple of days ago. I may carefully strip it down myself and check the capacitors, perhaps after writing my will!

> Edit2: oh and welcome to the forum! Glad to see another XT user.

Thanks, though it's really 'XT class' as I don't own a real IBM XT, just some interesting clones.