Young Electronic Aspirant's Corner – the Floppy „Anti-protector”


To become an adept of the electronic, a least at the beginning all what one must know is what the basics elements such as resistor, capacitor, a diode are for. That's all. ;)

A diode, huh =)? Right! And if... If we talk about a derive of this one – a photodiode? This bauble is an integral part of C64's floppy drive and serves as a „main reporter” whether a floppy disc is write protected or not.

Ha! I want here at the beginning to warn that these are only my personal assumptions that the 1541-II has a photodiode detecting mechanism. It may be that it is a phototransistor instead. So, sorry for my mistake, if there is one. :)

So coming back to the article. What we gonna do today is to install a „kicker” to our 1541 II floppy. I called this „kicker” using a mysterious name - an ANTI-PROTECTOR. The father of this idea is Spider from Tropyx/Apidya/Lasser. Once he was at my place and we were having a conversation, when suddenly I noticed a big light-bulb over his head (he has noticed the same, you may guessed ;). I immediately commenced to make this idea real and after few steps it figured out to be very easy as a solution. What is needed is to open the floppy and localize this photo element ;), which can be found on the lower-left floppy's corner on the level of a cut in the floppy disk, on the small, greenish board. There you gonna find two small cables coming from it.

Now what is needed is: a small two-positioned switch, two small cables and a soldering-iron together with a solder, of course. Not too much, huh?

These two small cables need to be soldered, separately, to these two cables already found in the floppy drive coming from the greenish board. Next - the switch. It must be soldered to our two cables and voila. Let's test our anti-protector „kicker”.

Take a new 5,25" floppy disc, WITHOUT making a hole in it. Or take a used one, but write-protect it with an adhesive tape (not transparent one ;). Format it. If you see the „DRIVE NOT READY” text, switch our small switch and repeat the formatting process. Now you have it. :) Or at least should... If there is still something not working as it should, please verify that all the soldering. Perhaps your process was not made properly. It must work!

The last step left is where to place the switch... Well... it is a question of esthetics and usability as well so choose it on your own. One can do a small hole on the left side face, another keep it outside. If the first solution is taken under the consideration then a small hole must be made in the disc-drive ;). One may use a soldering iron, but this job, as you know, stinks ;). More clean, but also kinda more time consuming is to use a drill and a file instead. To finish you may polish the hole using a sandpaper and glue the switch with the glue of your preference (be careful not to pour too much of liquid on it, otherwise the switch will be jammed. ;)

The only drawback I have encountered was that sometimes I had a „DISC ID MISMATCH”. To get over it, a standard @I must be executed and everything will be OK. At this point, I have not found a better solution for this alert. If you have one, please share with us.

Pros and cons.

What are the advantages of installing the anti-protector? 1. Before all – the comfort. When new discs are bought, very often the protection must be cut out manually (which may result in, in the worst case, destroying a disc). With the anti-protector – click! - and voila :). After filling the disk with the programs (or demos) of your preference the floppies are already protected! Since the protection were not physically removed at all (cool, huh? :). 2. Fun and a pleasure of doing some easy electronic soldering :). 3. The manual issues, like making a hole in the 1541II may be in some cases quite unpleasant. But it is not necessary.


This is a very simple and comfortable solution. I personally wonder, why this has not been introduced on the mass scale while the floppy drives were still in the mass production. Bizarre.

Aaaa.. One thing. Once I found a 5.25” floppy without any protection hole in it. As far as I remember, these discs were produced for the IBM PC.

Well. Now, have a great fun with installing and using the anti-protector!

Article written by: H.M.Murdock of Tropyx/Oxygen64/Draco/Lasser

Translation: Sim / Wanted Team, Lamers, Resistance, Titan...