On Sep 29, 19:10, Tony Duell wrote: Yes, I sort of included that in "alignment" -- in the electronic sense. Actually, not all Disk][s seem to have a pot there; and it was some time before I worked out how to set it properly (the Apple tech manuals I had in those days didn't mention it) and I had to wait until I got a Sony manual to figure it out. I remember asking once Motorola for the MC3470 datasheet, and the UK office told me it didn't exist! -- Pete Peter Turnbull Dept. of Computer Science University of York