IDE CD drive - eject pin?

[Zac67]

I'm afraid the logic for the button sensor is in the tray itself (most everything besides the IDE I/F usually is).

The only feasible way I see is a HW/SW combination: use some unused data line (parallel, serial, joystick port, secondary mouse button, ...) to hook up a button and write a small prog to monitor that line and issue an eject command when necessary.

Another option is to run a flexibel cable from the tray to the back of the drive, but that's probably hard to do in the first place and might become a source of trouble later on.

[Zac67]

Got another idea:
Put a reed switch somewhere in the tray and the corresponding magnet below/on top of the drive - you may have to cut a hole into the drive top/bottom to reduce shielding, but otherwise it's pretty nifty.  :-P

[Zac67]

motorollin wrote:
@Zac67
How would I operate the reed switch using a button? Maybe an electromagnet which is switched on using the eject button on the case?

Yes, exactly. You could also use a permanent magnet that is mechanically moved to approach the reed switch, but a electromagnet could be smaller and electrically switched. You should be able to fit the switch somewhere in the tray (corner) and it has the advantage of requiring no extra circuitry.

The phototransistor idea isn't bad either - you might get away with a passive solution (no amplifier circuit in the tray), but that would have to be tested. One advantage could be the far greater distance possible between actor and sensor. Plus if you've got space problems, a phototransistor can lower the size constraints of a reed switch.