[net.micro.apple] Apple disk drive question

zben@umcp-cs.UUCP (11/02/83)

[..]
Why does write protect switch connect to motor phase 1?  So the DOS can
test for write enable?  How else would it know not to try to write?
I recommend a close comparison of the controller and disk schematics from
the DOS manual with a copy of "Beneath Apple Dos", with particular
attention to the coding sequence given for "testing write protect"...
Ben Cranston       ...seismo!umcp-cs!zben       zben@umd2.ARPA