"Micro Switch" keyboards

[unclefalter]

Hi there,

I'm new to all this so forgive me -- have long been a fan of the IBM Model M and grew up on them. Still my favourite.

Anyway, I am presently working on a project to recreate Don Lancaster's 1973 TV Typewriter. On that project, he used a keyboard that was before my time and took some investigation to find something close. In his Radio Electronics articles, he simply called them 'surplus keyboards'. One day I happened upon this one on ebay and grabbed it. The keytops were identical to the TV Typewriter, other than color, which he had painted or rearranged.



But then I discovered this site, and saw a Burroughs and Honeywell unit that also had the same design of keys. So I'm wondering now what he really used, which may be impossible to find out as even he doesn't remember the exact model. And I'm wondering who really made all these. I've had it suggested to me that they were all made by Micro Switch?

I'm also wondering how rare these are. Back in Don's day, they were pretty plentiful and available, but now the only place I see them for sale, very occasionally, is ebay. To recreate the TVT I have to arrange the keys on mine a bit and paint the 'callouts' (think that's what they're called) black. I'm wondering if I'm committing a crime against posterity doing that. I'm an experienced railway modeller and have expertise duplicating plastic parts. Part of me is thinking maybe I should leave the original keytops alone, use the switches instead, and make new keytops that I can paint without feeling bad.

I was hoping to find more of these out there and purchase one or two more but they seem to come up very rarely so that's the reason for my pause. They seem like a very versatile, easy to configure keyboard.

I have a blog here for those interested in what I'm doing. http://www.bradhodge.ca/blog

[seebart]

Welcome to DT! Although I am very much "into" vintage keyboards from the 1970's myself I do not know Don Lancaster's 1973 TV Typewriter. As I understand it this was a kit that Don built and then it became popular? You're certainly not committing any crime changing your own build. I doubt that these were manufactured by Micro Switch, but I certainly do not know that for sure. Nice project unclefalter! Keep us updated. What's the purpose of having large round keys like that btw?

But then I discovered this site, and saw a Burroughs and Honeywell unit that also had the same design of keys.

Care to show us those? A link will do.

[unclefalter]

Thank you for the welcome!

Yes the TVT was a device Don designed and then described in Radio Electronics. I believe in the early 70s video monitors were insanely expensive and teletypes were not something people had around in the home. His genius was figuring out that most people had television sets, and if you could get computer graphics/characters to display on a TV set, you were well on your way to a whole host of things, including home computers, terminals, etc. Technology wise the TVT is pretty laughable today -- it does exactly what it says, nothing more, nothing less. Backup options in the article included polaroid cameras. But as I understand it it opened doors and inspired real computers like the Apple I. You could build the TVT pretty much from scratch or order pre-made PCBs from SWTPC, but the rest of the assembly you were on your own.

I've been collecting computers for years and have about 100 pieces. One of my favourites is my TV Typewriter II, which bears no real relation to the original TVT (it was designed by Ed Colle to get around some of the expensive ICs used in Don's design), although it too was covered by Radio Electronics in (I think) 1975. I really wanted to get my hands on an 'original' TVT but I've never seen one for sale anywhere. So then I decided hey, since the TVT is one of those rare machines you can build on your own and still call legitimate, why not replicate Don's original prototype case design, build a 'new' TVT using vintage parts.. and then I have one. And that's what I've been doing, collecting 1973 vintage ICs, learning how to make the boards, etc. But the keyboard for years was a stumper. Don called it an 'IBM EBCDIC' board, but that's just the standard encoding it used. Then I stumbled on an ebay auction with a keyboard similar to mine (won by someone I think who is also on these forums). I stayed out because another person had promised they had one to sell to me cheaply, but didn't follow through. So then this one came up and I snatched it. And I was so sure it was *the* one.. until I found pictures of the Honeywell and this Burroughs https://farm8.staticflickr.com/7474/158 ... e0ca_b.jpg. Same keytop design and appears to be same switches in other photos. So that got me wondering, who really made these things? And which vendor did Don actually use.

Now I'm hooked and want a few more vintage 'keypunch' style keyboards just to collect. They're neat looking. But yeah, I need the round keys because I want my replica to be the same as Don's. And I'm feeling a bit uneasy tearing apart a vintage piece whose rarity I do not know.

[Chyros]

Welcome to DT! You'll find many people here who like vintage stuff .

Nice board! It looks very impressive, like something out of a Bond film xD .

[Muirium]

Looking up TV Typewriter at the Wikipedia, I found this section which seems quite relevant:

Keyboards

Today keyboards are readily available, inexpensive and have a standard interface. In 1973, new keyboards were only available to computer and terminal manufacturers. Surplus keyboards were available to hobbyists but they often produced codes other than ASCII, such as baudot or EBCDIC. The TV Typewriter project and kit did not include a keyboard. The unit on the September cover shows a keyboard project Don Lancaster did in the February 1973 issue.[8] This project involved hand crafting 55 key-switches including fabricating the springs for each key-switch. Most hobbyists chose to use a surplus keyboard and modified it to produce ASCII codes. Don Lancaster's prototype TV Typewriter which is now on display at the Computer History Museum has a surplus keyboard with an ASCII encoder circuit that was published in the February 1974 issue of Radio-Electronics.[9] The plans for this encoder were also included in the TV Typewriter booklet

Popular Electronics (April 1974) featured a complete keyboard kit designed by Don Lancaster and available from Southwest Technical Products for $39.50.[10] The first version used simple RTL ICs to decode the key matrix. The design was soon improved to use a full featured keyboard encoder IC.

Sounds like you need that February 1973 issue of Radio-Electronics. Then you could build your own! Which, I agree, is better than modding anything as vintage as what you have there. Speaking of which: these are strange and vintage keyboards for sure. Never seen anything like them!

Seems strange to us that there were keyboard assemblies kicking around in the early/mid 1970s, before there were computers to use them. But I read the same thing about 1976's Apple I. It was sold as a bare, assembled system on PCB. You had to supply your own keyboard, neither made nor sold by little startup Apple. Woz had indeed included some (by then) standard input to hook something up to.

[OleVoip]

The keys of the TVT prototype keyboard (the one from the museum, not the one from the magazine cover) and those in the first post look exactly like late-1960s/early 70s Micro Switch keycaps. The black and white ones of the Burroughs I remember from my childhood. Maybe my fondness of square keycaps with a circular knob (RaFi, Siemens) subconsciously originates from those, which definitely wore a "Micro" (Micro Switch) mark - the switches, not the keycaps.
The layout of the keyboard in the first post, with its upside-down overlaid number block marked in blue, is a typical Micro Switch layout from around 1970 for TTY-like devices, which only have capital letters and no shift keys; instead, they have keys that switch between numbers ("NUM" or "FIGS") and letters ("LTR" or "LTRS"). Unless you overpaint the key labels, you are quite a long way away from the layout of the TVT keyboard - simply rearranging the keys won't suffice.

[unclefalter]

Yeah originally I wanted to do a replica of the cover unit. But the problem is those keytops -- they were (I think) a one off job by a company called Mechanical Enterprises. I've never found anything that works as a stand in. So that's why I went prototype -- I'd seen these MDS keyboard come up from time to time.

I didn't fathom how hard it'd be, psychologically to take it apart. But after a long think, I realized the whole point of this project was to replicate the prototype and have what I cannot buy. I'm confident another MDS keyboard (or Micro Switch) will come up again some day and I can buy it and keep it as a collector piece.

I'm pretty sure after looking through this site and documentation that Don used a Honeywell unit. There are pictures over the years of the prototype where the plastic surround blocks have slid away and you can see the side bracket exposed. Looks just like Honeywell. The prototype goes 13.5 full keys across, including the surrounds. Mine is 14. So I removed some switches and rearranged to get 13.5. The half key I have buried in a recess on one side of the 'TVT' case, and then the other side rests on a shelf. That was the only way to do it and it leaves me with the entire case being 11.75" across, which is what the museum confirms is the correct width.

So then it was down to paint and again after a little moral crisis I decided to go for it. I want what I cannot buy, and as tempting as it was to leave the keycaps as they were, to get a 'TVT' keyboard the whole thing had to be rewired anyway -- might as well get what I really wanted. I used an acrylic spray which went on well and doesn't seem to eat the keys *except* if you try to scrape it off. I did that on one key as a test, trying to remove a tiny bit of overspray and the plastic had gone soft. Yikes. I painted an entire row black.. but no sign of melting. And after the initial jitters I actually think I made the right call. I'm hoping to end up with something unique I can take to VCF shows. People can always go see the real one at the Museum but they'll never be able to use or interact with it. This one they can.



The hard part is going to be painting the keytops themselves. For the 'callouts' or surrounds, I've figured out a process that involves putting a carefully crafted tinfoil 'cap' on the keytop and then spraying the callout. But to spray the keytop will require making some kind of 'mask' they fit through in paper/foil. No idea how I'm going to cut holes that precise. I don't have enough blue keys, so paint will have to happen there too.. but so far the only paint I've found with the right color is engine paint. No idea how that will react with the keys and am feeling a bit anxious about that. Thinking maybe of trying to paint on pure acrylic by hand. That I know won't react and can be easily removed.

The final trick will be the lettering. On close examination of the second picture here:

http://www.computerhistory.org/revoluti ... 7/296/1135

It looks like he did his own decal work. Not sure how I'm going to replicate that other than copying from that image and printing it on maybe label stock?

[mr_a500]

I'm sure you've seen this thread with similar keyboards:
http://deskthority.net/photos-f62/burro ... t9180.html