I think comparing how many original ST's (with no internal drive or TV RF modulator) or original 1984 Apple Macs are still working is a better way of looking at it than IBM PC-XTs. Both those machines are unique in a way and could have been kept alive with parts from the next model down. I think however A1000 owners are just that bit more passionate about keeping their machines alive than the equivalent Atari ST/Mac classic owner.
1. PCs of that era were only business machines.
2. The PC-AT purchased to replace the XT had 100% identical functionality so made the original redundant.
In todays world of Xbox 360 struggling to make it to 12 months use (and stupid fan boys on their 3rd console which they purchased from their own monies!) yes it seems incredible that such machines should work.
However in my summer house there is both a 1979 Atari VCS and a 1980 Commodore VIC-20 (serial number in early 3 digits) working flawlessly so for me it is no surprise. And even if one of them should fail I would fix it because a working C64 or Amiga is no replacement for a VIC-20
But then some models of PET are extremely rare because they had no love and were junked by the owning business when they started to play up. Sad but true
