View Full Version : Wanted... a PDP 11/70 toggle switch 'cap'

February 8th, 2010, 12:37 PM
Somebody must have a warehouse full of these somewhere...


It's off a Datasystem 570 (basically a blue 11/70). This is the lighter colour blue of the two types of switches.
One of my switches got broken! :( ...well, it came that way.

DEC part number is 1210796 (let me get my glasses...)

It's probably the same as the switches on the KL-10.

Does anybody have any! Please :)
Money will be paid! And / or exchange red or purple versions of these that I have on a spare console.

Also, the two mode select knobs are missing too, but I think I can find a substitute for these (assuming DEC used off-the shelf parts)


February 16th, 2010, 11:23 AM
Well, nobody came up with anything so I did the following:

1] Went to Halfords (a UK car accessories retailer) and browsed the range (around 300) of touch-up spray paint cans, with switch cover (apparently also called a switch 'handle) to compare to.
2] Found Lada (lol) 'Adriatic blue' to be the closest match (about 95% - it's a little too light)
3] I also bought some 600 grit sandpaper and a spraycan of plastic primer
4] Cleaned down the donor switch cover (a red one) with isopropyl alcohol, and allowed to dry
5] Rubbed down the cover to create a better surface for the primer to stick to (basically enough to dull the plastic), washed with 50/50 water/isopropyl alcohol and left to dry
6] Clipped the cover to a jig I made from an old switch (intact, but mechanism inside was a bit rough) soldered to a rectangle of veroboard with some foam foot pads to keep it stable
7] Sprayed the primer and left to dry (around 30 mins in warm blowing air)
8] Sprayed the blue coat and left to dry (4 hours... yes, too short maybe but I wanted to see what it looked like)
9] Clipped it into my board and here we are:


Can you guess which one it is? (it's not that hard)

February 16th, 2010, 11:37 PM
Nicely done, I can't tell but I'm guessing the one on the far left. (smarter to keep it separate, harder to compare)

February 17th, 2010, 01:41 AM
You're too kind... of course it's the far left one! ;)

Yes, you're right - mixing it in with the others makes it more obvious. I considered which side to put it on, but thought the right-hand side would get more use (Start switch). I might try putting it (Dep) in between two of the darker blues (Exam and Cont).
Does anybody have info on the rotorary switch knobs? I'm hoping they are 'off the shelf' hardware. Does anybody have a part number or manufacturer?


February 17th, 2010, 03:40 AM
Looks good to me. Wise choice to put it on the left.

Some day I might have an 11/70 of my own. :)

March 21st, 2010, 11:51 AM
Hmm, perhaps somebody could make a 3D model of such a switch. Then anyone with a Cupcake CNC (http://en.wikipedia.org/wiki/Cupcake_CNC) could print them.