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From: harold.h@genie.com (Harold Hislop)
Newsgroups: comp.sys.apple2
Subject: Re: Disk II drive: Override switch on write-protect
Date: 21 Dec 1995 06:02:11 GMT
Organization: via GEnie Services (1-800-638-9636 or info@genie.com)
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Sender: harold.h@genie.com (Harold Hislop)
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buggie@indus.unm.edu (stephen e buggie) asks:
[edited for brevity]
 
>> I have several Disk II drives.
>>...how to install an OVERRIDE SWITCH on the front panel of the Disk II.
>> Such a switch will allow the user to write to the disk even if a
>> notch is absent from the disk.
 
>> QUESTION:  Would the override switch be wired in SERIES (in-line with)
>> or in PARALLEL (across the two wires) with the write-protect microswitch?
 
Use a SPDT (single pole, double throw) center off (three positions on
the handle) switch.
 
Clip one (either) wire that goes to the orignial write protect switch and connect the end of this wire that goes to the analog board to the center (wiper) terminal of the new switch.
 
Connect the end of the above wire that goes to the original switch
to either of the outside (throw) terminals of the new switch.
 
Add a wire from the =other= side of the original switch to the remaining
outside terminal of the new switch.
 
Figire out yur physical mounting, and mount the new switch.
 
The switch will now have 3 positions:
 
1) Always Write Protected (Center position)
2) Always Write Enabled (suggest mounting switch so this is in the UP
   position... that way accidentally bumping the switch is less likely
   to write enable a disk when not desired)
3) Normal (opposite position from #2)
 

--
-Harold Hislop
Hardware Coordinator,
Apple II RoundTable, GEnie
14Mhz/32k TWGS, 1Mb Rev-C RamFast, Prototype ROM_03 in tower
(Heritage Mac hardware also spoken (great IIgs peripheral ;))