It does sound like an XT. The first PC I used was an XT-286; the precursor to the AT. It had a massive 20 MB hard drive!

I still recall that the expensive accounting software for which my father purchased the computer required an ISA card to run it. Now that's anti-piracy!

"The first PC I used was an XT-286; the precursor to the AT." It was actually a smaller case version of the AT.

I believe it had a different cpu (6mhz vs 8mhz) and different a motherboard (16bit vs 8bit).

You are correct about the clock speed, but not the bus difference.

"In 1986, the XT/286 (IBM 5162) with a 6 MHz Intel 80286 processor was introduced. This system actually turned out to be faster than the ATs of the time using 8 MHz 286 processors due to the fact that it had zero wait state RAM that could move data more quickly."

http://en.wikipedia.org/wiki/IBM_Personal_Computer_XT

"(16bit vs 8bit)"

False.

I think it's PC-XT. I added a lot of those parts with bits I found in a Hamfest back in the 90s. It's been mothballed for ages because I have nowhere to put it so I've honestly forgotten.

I'm betting XT. It sounds identical to what my father had.