Re: Pinout Voltage on IIc Disk Drive Port

[dempson@actrix.gen.nz (David Empson)]

Frank Townsend <ftownsen@iamdigex.net> wrote:

> The TIL says the following:
> 
> For IIc Plus Pin 5 is -12 volts
> http://til.info.apple.com/tilarchive.nsf/artnum/n3798
> 
> For IIc Plus Pin 5 is +12 volts
> http://til.info.apple.com/tilarchive.nsf/artnum/n1419

[I see you meant IIc for the second one.]

> Are both of these correct?

No.  Pin 5 is -12V on both the IIc and IIc+ (and the UniDisk/DuoDisk
controller, and the IIgs, and every other Apple II model which uses this
connector, and the equivalent pin on the Disk ][ controller).

My reference: Apple IIc Technical Reference, both first and second
editions.

The TIL got this wrong in article 1419.


I seem to recall reading somewhere that _something_ doesn't provide -12V
on this connector, which prevents it from supporting some types of
drive.  I can't remember what it was (perhaps the IIe card for the Mac
LC?).

-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P O Box 27-103, Wellington, New Zealand