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Very, very old message, so hopefully you are still in the group. I need a cable too here in 2024. I have plenty of GPIB cables. They are rather thick. If I can come up with the edge connector, it there a schematic of the wiring of that cable? Is the IEEE cable the same as a GPIB cable?

Eww, this was a long time ago and think does not work anymore. New Link?

I meant to say "can not" burn those roms currently. Waiting for a TL866-3G to show up so I can burn 24 pin EPROMS.

P.S. - Any US Based vintage puter stores that carry PET parts, and other things?

Well, it does have a bad pot on the display (brightness sticking out the back). I need to fix it or find a suitable replacement. That's not the problem. Tore down completely, cleaned the PCB in war, soap and water, dried it out. Cleaned the inside of the case. Both look close to new...

Thank you. I didn't see I was on the wrong page. If I can burn this rom (Right now my TL866II cannot burn 2716 or 2732 roms), which socket does it go it? You said the "edit rom". uhhh, which one is that? I am very new to the PET series. I think there are what four BASIC ROMS, The Kernal...

Did that every get posted?

I was playing around again. Instead of a board jumped I wanted to put two 1N4148 in series, passing only the positive portion of the pulse. I put them together wrong. The unblanking pulse is now perfect going to the neck boards. I can crank the screens all the way up and not a hint of jail...

I was wondering about that. There is another transistor in parallel with the one that produces the blanking pulse. It looks like it ties in with the programmable horizontal driver IC (controls width, centering, etc.). I am wondering if it is supposed to be turning on just as the other one is...

During my experimentation, I blew out the initial rectification (to ground) diode for the flyback unblanking pulse. A 1N4148 gave me jail bars all across the screen. So I pulled on from the donner board that appeared to be in the approximate same location (donner board newer and double-sided...

Okay, yes, the unblanking has ringing in it. This explains why it worked good with its original flyback (until it failed). The original was a - 1017D, which seems unavailable. The donner one is a -1003D. It's PCB had a lot more complex un-blanking circuit, at least a lot more parts to get rid...

Wow, thank you for that! Was a great read and advice. Today: Installed brand new "exact same flyback" from ebay and it smoked. Put in the old working donner. replace horz driver again, and damping diode. Scoped and scoped. Yes, I need a 100:1 probe. Replaced yoke, and that helped a...

Dead with original flyback. Primary rings good, secondaries do not. I used the horizontal output from the donner and the original one, same issue. Not a single fricken adjustment on the board which includes the horz width coil). The doner board did have a width adjustment switch, this one...

Sorry I can not get my reply to not show as a quote. I tried with the original horz output from the donner and from the bad one. There isn't a single fricken adjustment on that board. The Service Manual is useless "replace board". I'll have to look, the horizontal width coil may me...

Hello, I have never seen a CRT/TV do this before (I used to work in TV repair, but that was in the late 70s through 1983, so I am a tad rusty). I replaced the flyback and horz output to get this iMac to come on. The unblanking has vertical strips in it, missing video. This one had worked...

Thank you!

Does anyone have schematics for the PS on the right? It is not in the tech manual.

Hello there. I have been restoring a very early Model 4, non-Gate Array with 128K Ram and B&W Screen, not green. I can boot a bunch of disks I got from Australia just fine in the lower drive 0. I can not read any disks or format any disks in the other drive (Drive 1). It spins, the RPMs...