Sperry HT - DOA

The very first computer I actually owned (other than my TRS-80 Pocket Computer 4) was a Sperry HT that I bought through the college.  It was cheaper than the competing IBM PC-XT and ran faster.

Over the years, I out grew it, food chained it and it was gone.

I was able to pick up one on eBay recently.  Supposedly "tested to power on".  "Tested to power on" means, "we plugged it in, flipped the switch, the fan came on and the lights lit up."  Well, that wasn't true.

The power supply was packed with dirt and would not power on.  Luckily, a cleaning made it power on.  As expected the system wouldn't even POST.

I reassembled my Sperry Portable systems that are known working and tested the boards in the Sperry HT.

The video board was toast.  The MFM hard drive controller was toast.  I was unable to test the mystery board that I found in it because I have no idea what it's supposed to do, but odds are that it's toast too.

I finally got the tech manual for it and went through the diagnostics steps.  tl;dr no POST beeps which means that the timer or DMA is toast.

It seems that the system took a power hit and it took out most of the stuff on it.

The only thing that survived looks to be the 360K floppy drive.

So, I'm going to reassemble what I have and put it away for a while.

I was hoping that the board from the Sperry Portable would fit in it, but the layout is completely different.

I also thought about sacrificing my "IBM PC-XT from the Negative Universe" and putting everything into the Sperry case.  But I don't think that would work either.  The cards are in the correct place, but nothing else would fit.

So I'm thinking of just trashing it.  But I need to think about that.

I can't say this was a big surprise.  The Sperry HT was not known as a reliable system (also known as a Leading Edge Model M).  It was a cheap, but not something that was made to last.