1050 3-mode Write Protect Switch Methods

[+Nezgar]

I've seen this done a couple of ways, but I believe the easiest is to disconnect the IR LED/Sensors from the drive mech, and simply hard wire a 2 position 3 terminal switch either +5v or Ground from pins 1 or 2 to the sensor pin 3. ie like this post from tf_hh: http://atariage.com/forums/topic/258687-what-are-the-meaning-of-the-1050-j11-pins/?p=3624717

A slight enhancement to this for a bi-color mode LED is use a double pole on-on switch (2 position, 6 terminals) wire a bi-colour LED to be either red or green depending which polarity the LED get’s its power.. In my case, I replaced the main power LED, but I’ve seen others add a 2nd LED for this.

With a 3 position on-off-on switch, it looks similarly easy to implement Write Always:up (power from the IR LED pins straight into the detect pins), Read Only:middle (open circuit), Write Maybe:down. Example schematic posted here: http://atariage.com/forums/topic/143931-1050-write-protect-bypass-switch/?p=1748552

I would like to wire up a 3 position switch so that ‘write maybe’ is in the middle. IE: up:Write Always, middle:Write-Maybe, down:Read Only. The only way I can think to do this so far is using a 3 position slider switch, like this: https://www.mouser.ca/ProductDetail/CW-Industries/G-168S-3011?qs=sGAEpiMZZMtHXLepoqNyVXvKblAm878lNKc10eIgdyU%3d A three position switch where all three positions connect a circuit would be ideal, but a non-slider type does not seem to exist...

I wonder how to do this because someone appears to have done this according to the description of this 1050 on ebay: https://www.ebay.com/itm/292444852785 “This drive also has a 3-way write switch. The top position places the drive in write protect mode. No writing to the disk is permitted. The middle position is for normal (stock) drive operation. The bottom position places the drive in a write always mode, write protected or not.”

The Happy controller board does this, but that has other IC’s involved doing some logic. In the controller’s “Write Maybe” mode it will even turn the light on or off in realtime depending on what the photodiode sees.

Edited May 23, 2018 by Nezgar

[+Nezgar]

I messaged the seller on ebay. I wonder if he will reveal his method. I'm thinking he must be using something like a transistor or a relay to restore the 'stock' mode for the middle switch position.

Edited May 25, 2018 by Nezgar

[JR>]

It's been a few decades, but that's how the one I built in to my first 1050 worked....center = use notch.

 

LED is RED for write always, yellow for use notch, and green for never write. Pretty sure it was just a dp3t switch (center off) and a couple of diodes and pull up/down resistors and a tri-color LED. Don't remember if I found instructions somewhere or designed it myself.

Edited May 25, 2018 by JR>

[JR>]

Sorry, faulty 3 decade old memory I guess. I popped it open, and center position is led=yellow, but it appears that in the center position, the wp sensor is just left open circuit...full WP iirc. the resistors and diodes were for the 3 color LED circuit

Edited May 25, 2018 by JR>

[ijor]

I wonder how to do this because someone appears to have done this according to the description of this 1050 on ebay: https://www.ebay.com/itm/292444852785 “This drive also has a 3-way write switch. The top position places the drive in write protect mode. No writing to the disk is permitted. The middle position is for normal (stock) drive operation. The bottom position places the drive in a write always mode, write protected or not.”

 

The Happy controller board does this, but that has other IC’s involved doing some logic. In the controller’s “Write Maybe” mode it will even turn the light on or off in realtime depending on what the photodiode sees.

 

We had a detailed technical thread about the Happy controller not long ago that included schematics. The Happy board has a couple of IC's, but note that it implements more than just a switch or two. The software not only that can read the position of both switches, it can also (depending on a couple of jumpers) bypass the switch and force write protected or write enable.

[+Nezgar]

We had a detailed technical thread about the Happy controller not long ago that included schematics. The Happy board has a couple of IC's, but note that it implements more than just a switch or two. The software not only that can read the position of both switches, it can also (depending on a couple of jumpers) bypass the switch and force write protected or write enable.

 

Yeah, the happy controller is definitely an interesting, feature laden device. I got my first controller in a drive a few months ago. I played with the ability to send commands to the happy drive to configure the Write-Protect or Write-Enable. Steve Carden's 'happy.com' included with RealDOS also has options to configure this without using happy's utility disk. It was interesting to play with, but I had the humerous thought about how malicious software or copy protection schemes could have abused that and reconfigured a drive a user had intentionally write protected to allow writes again and trash their disk! Aside from the happy controller's programability, it was 'neat' that the 'write maybe' mode LED would reflect the state of the photodiode in realtime.

 

I don't do well with schematics, just muddling this through my basic electronics knowledge that's growing... I see the photodiode outputs about 1.22V when receiving light directly from the UV LED.

[ijor]

 

... but I had the humerous thought about how malicious software or copy protection schemes could have abused that and reconfigured a drive a user had intentionally write protected to allow writes again and trash their disk!

 

Well, that's precisely the purpose of the jumpers. I always had my controllers configured with the jumpers that disabled the software override. Just in case ...

[JR>]

Looks like there are a few true 3T toggle switches here. Might be a bit on the large size. You can give your 1050 an Atari 2600 vibe with a couple of them. Maybe add some woodgrain to the faceplate too

 

http://www.surplussales.com/switches/swtoggle-1.html

Edited May 26, 2018 by JR>

[+Nezgar]

Looks like there are a few true 3T toggle switches here. Might be a bit on the large size. You can give your 1050 an Atari 2600 vibe with a couple of them. Maybe add some woodgrain to the faceplate too

 

Hah, you mean this thing?

Thats pretty funny. But it looks like it's intended to be surface mounted, and would have problems being mounted to a faceplate as it looks like it the switch base protrudes from the surface. I guess a big enough hole...

 

This 3 position slider could work, and would mount onto the faceplate. A switch like this might also work to switch between 2 1050 ROMs (ie Stock/USD or Happy/USD) to have the middle position throw +5v to pin 2 of the 555 timer causing the drive to reset on it's way to the new OS, but might not work because of the miniscule time gap between the reset release, and the power being applied to the OS chip on the other side...

 

I've seen rotary switches that could work too... But mostly curious how people did it with a common on-off-on switch.

Edited May 26, 2018 by Nezgar

[JR>]

.. But mostly curious how people did it with a common on-off-on switch.

Probably just a bunch of people, like me, who don't remember how their switch actually worked. Even on the Happy Controller, write maybe is the down position, not the center.

[+Nezgar]

Even on the Happy Controller, write maybe is the down position, not the center.

Oh my, you're right! I just looked at my Happy Controller drive and sure enough that's what that paper on top of the drive says. Guess my memory is also playing games with me. .