A 1970s disk drive that wouldn't seek: getting our Xerox Alto running again

1 · Ken Shirriff · March 31, 2018, 4:53 p.m.
Our vintage Xerox Alto has been running reliably for months, but a couple weeks ago the disk drive malfunctioned and the heads stopped moving. With a drive that wouldn't seek, our Alto wouldn't work.3 After extensive debugging and studying the drive's complex head movement control system, we discovered that the problem had a trivial fix. This blog post discusses our adventures debugging the Alto's Diablo hard drive and how we got it to work again. The Alto was a revolutionary computer designed a...