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A little offtopic but my stats: 1x IBM 5153 = partially damaged but still in one piece 1x IBM 5151 = completely destroyed one side/top. 2x IBM...

I found a PNG with the pinout for using Disk Change with 8" Floppy Drive. PC(34p) 8"(50p) Description > 2 TG43 8 ...

I picked up some hex Omnibus boards that had the gold fingers cut off as a source for hard to find ICs. I was a little disappointed to find that a...

That's all I use is cheap DMMs. Right now have a yellow no-name for my general computer/guitar electronics stuff, and then a dirty older red one for...

My knock-around DMM that I picked up 6 years ago is this one or its first cousin. It's not bad for what it is and the big display even has a...

That’s one of the references I was trying to find. I suspect the voltage will fall not rise if the capacitor fails open circuit though. Dave

The transformer is a constant voltage model. It has a quite big air gap. That capacitor saturates the core which is limiting/regulating the output...

That is most likely a ferro-resonant circuit. The capacitor and winding is tuned to be able to stabilise the output voltage. DEC used them a lot...

isn't this a ferroresonant transformer? http://www.electroncoil.com/ferroresonant_transformers.php I found this in many DEC transformers. Like...

Cheap multimeters with analog meters are junk (as are older analog ones that haven't been well preserved), but I've had mostly positive experiences...

The corrected link is:- http://s100computers.com/My%20System%20Pages/Serial%20IO%20Board/Serial%20IO%20Board.htm#Serial%20IO%20Board%20V4.2

More collectors and less stuff to buy so prices rise. The key to a cheap hobby is to collect stuff nobody else wants. I was lucky enough to...

MCE2VGA work fine on IBM 5155

BP80 is what I got, yes. I wasn't and still am not completely sure how many additional bus lines I might need for 'TRS-80-ish' things. It may be...

My experience with Offerup and Mercari has been pretty good. Even Facebook Marketplace. You just have to manage it very tightly. When buying I have...

Replaced the capacitors and the voltages are much better. Only still no picture on the screen. I do get all the beeps but that's all. I bought a...

I'm in VA and would be happy to pick up in NC if it is still available.

for a long time those trash HF ones were actually free with a coupon

Tom, My guess about the isolated transformer secondary and capacitor would be a harmonic filter of some description. If the capacitor goes...

I have 2ea cheap $9 ones from Harbor Freight. They work well enough. They are within 1 digit of my 5 digit Fluke. The Ohms usually start with about 2...

It's quite a bit more than just a pin converter: https://github.com/lfantoniosi/mce2vga

I got it.

Good to know. I wish I could see some video of it working with a PCjr so I can decide if the quality of the video output is worth the price.

I have now fixed the power supply. It turned out to be a 2 uF 660 VAC capacitor with a dead-short. Here is the relevant page from the schematic with...