Ever since I was in high school I wanted a PDP-11. Something about an old '11 running RSTS/E with RK05's was fascinating. Maybe I never got over "Program lost, sorry."
I didn't really intend to start a retro-computing collection. It just sort of happened by accident.
Recently I saw an 11/34a on eBay and decided to bid. I won and it arrived a few weeks later. I cleaned it up and turned it on and the console worked but the memory was bad so I turned it off.
The pdp-11/34a
A few weeks later I got bored one day and decided to debug the memory. I discovered that the +12v supply was missing. Turns out a fuse had blown. Knowing full well it would blow again, I replaced it. The memory still didn't work but the 12volt regulator got very hot. I broke out the DVM and discovered the 12v rail was shorted to ground. Suspecting a bad cap I started desoldering big bypass caps. On the second try I found one was shorted. This was when I discovered the term "reforming" and the technique of reforming old electrolytic caps.
Removing the cap allowed the +12 to work and the memory started working. I downloaded some code with vtserver and the 11/34a sprang to life. The only problem was that I had no peripherals. This led me to bid on a government auction for a vax 11/730. But that's another story.
More recently I boot RT-11 successfully, after copying it with vtserver onto a RL02. I also was able to copy a unix miniroot onto tape, almost. After about 4 hours of copying the machine just died. Most frustrating. All the supplies are good but something odd is happening with the memory. Simple memory tests work fine but vtserver prints out an odd malformed message when it starts up (I suspect when the MMU kicks in something bad happens).
time for more debugging.