Re: Eject button on an Apple 3.5 Drive

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

Bryan Villados <news003@macgeek.org> wrote:

> I'm currently making plans to build a custom case for an Apple IIGS. The
> Apple 3.5 drive is going to be internal, and I'm using the Apple IIc+'s
> internal drive and housing for this project. On this housing, there is an
> eject button with a red/black connector that normally connects to the IIc+'s
> logic board. From what I understand about the "external" version of the
> Apple 3.5 drive, the eject button signal travels along one or two of the
> 20-pins on the ribbon connector.

Nope.  The computer is not involved in a manual eject.  There is a soft
eject command which the computer can send to the drive, which is encoded
using a combination of signal lines, but there is no way for the IIgs to
detect (or prevent) the use of the eject button - it can only tell after
the fact by observing the "no disk in drive" status bit.

The button is handled inside the drive enclosure, probably by the
interface board generating a soft eject command for the drive mechanism.
(It also detects whether the drive is connected to a Mac or Apple II and
disables the button for a Mac.)

If you wanted to mount an Apple 3.5 Drive inside a IIgs, you would need
to include the drive mechanism and interface board from the drive
(without the interface board, the IIgs won't recognise the drive).
Since the interface board must be there, you can just wire the eject
button to its normal location on the interface board.

-- 
David Empson
dempson@actrix.gen.nz