Mike's PCjr Page

I've recently been noticing flaky behavior from my PCjr and after playing around with the system tonight I'm fairly sure something is up with it. Symptoms: Certain games seem to get stuck when they switch video modes: 1) Thexder - original disks - system asks to insert the original disk....even thou...

Is it not reading disks at all or is it not reading disks from other drives? I have had drives go out of alignment where they cant read disks from other drives but can read disks that are formatted on them and read them just back fine. If you need a PDF maintenance manual on the Qumetrak 142 I foun...

Dang, I just noticed this. I'll have to watch for another one, hope it went well!

I was looking inside my PCjr this morning and I noticed some strange coloring on the motherboard over near where the power supply was (I recently replaced it with the ATX power supply mod). I pulled out my old power supply card and noticed the Siemens B82723-G5-A12 part is leaking. I presume this is...

Cleaning the rails and the heads on the 5.25" drive takes care of most problems. There are some instructions on the documentation download page - look at https://www.brutman.com/PCjr/Eugene_Club_Docs/Care_and_Cleaning.pdf. There are probably videos on Youtube. Cleaning the rails is easy - use ...

https://imgur.com/7yqOFDW Hey guys I like to find a restore old computers, but I've never had a PCJr before. What a weird machine. I bought it from a guy that used to work for IBM. Part of his job was to upgrade sidecars to 512k for internal use at IBM. This sidecar is one that he upgraded. He also...

Does anyone have instructions on how to clean up and calibrate the primary 5 1/4" DSDD drive on the PCjr? My main drive works great, but a spare I have can't read any disks and I'm not sure how to get it working again. I did a head cleaning on it, but that's about it. The motor spins and the he...

Yeah, sorry, that was most certainly a typo! I suspect it may be the old power supply becoming marginal. It was occasionally having weird intermittent errors that would start going away if the computer were left on a few minutes and restarted. I should know more once I've had more time with the new ...

I figured I would post here some of my experiences getting video out of the PCjr adapted to VGA/HDMI etc. I have my PCjr monitor and it works great but I was curious how to adapt it to other video formats. So I've found the following seem to work: ----- C-128 RGBI DAC (http://www.bit-c128.com/) This...

What BIOS do you have on it? I know of the (now outdated) one that I adapted from XT-IDE in 2012 - are there others floating around? It's running 2021-11-12 (says based on XT-IDE BIOS v0.11). I remember reading in the forums about fixing an issue like this and though "oh, it's just got an olde...