User`s guide

From: Stephen Buggie
001- How do I add a write-protect On-Off switch to my
Disk ][ drive?
Adding an Auto/Manual Write-Protect (A/MWP) Switch
Often, as when doing copying, it is useful to be able to guarantee that a
diskette is Write-Protected whether or not the side is notched. Other times, it
is convenient to defeat Write Protection-- for example, when you wish to write
to a diskette side which is not notched. And, naturally, you also want a setting
which permits Normal, notch-controlled, Write-Protect.
Based upon a circuit suggested by David Wilson (Australia), the A/MWP
enhancement offers full user control of Write Protect. The switch's three
positions are
Normal: a diskette side must be notched to permit writing.
Protect ON: Writing is prohibited regardless of notching.
Protect OFF: Writing is allowed regardless of notching.
A/MWP Step-by-Step
Unplug the drive from the disk controller and remove the case.
Drill a mounting hole. This can be at a convenient spot in the back or in the
plastic front panel. On the front, a good spot is at the lower left, above and
to the left of the "in use" LED. Another open spot is at the upper right in the
space just above the diskette slot; but, we're saving this place for Part 2's
enhancement. (You can't use the lower right, of course, because this would mess
up the "Apple" logo!)
Cut three wires (Brown, Black, and White) long enough to run from the mounting
point to the Large Connector plugged onto the back, middle of the Disk ][
circuit board.
Solder the leads to a Single-Pole Triple-Throw mini toggle Switch: Brown to
center, White to one end, Black to other end. Twist the leads or encase them in
tubing.
Mount the Switch. Normally, the Switch handle will point ...
o- in the Black lead direction for "Normal" (center and White connected)
o- at Center for "Protect ON" (no connection).
o- in the White lead direction for "Protect OFF" (center and Black connected).
Mounting the switch with the Black lead on top is recommended because it is easy
to remember that Up = Normal. Route the leads to the area next to the Large
Connector. (Make sure no wires will get in the way of an inserted diskette.)
Locate the Brown and Black leads coming from the Notch Detect micro-switch. The
leads are the Brown (bottom) and Black (top) pair near the right end of the
Large Connector (as viewed from the front of the drive).