Does anyone know where I can find some keypad keys like the ones on the KIM-1? I thought about ripping apart an old phone but I don't really like that idea.

Searching on eBay isn't finding anything I like. But I'm probably using the wrong search terms.

Thanks for any suggestions.

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Cat; the other white meat.

Maybe try "20 Key Membrane Switch Keypad" or similar?

https://www.bgmicro.com/vintage-numeric ... kinds.aspx

https://www.bgmicro.com/SWT1109.aspx

They always have a random selection of keypads.

Thanks! I will look into those.

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Cat; the other white meat.

(also perhaps "20 Key matrix Keypad")

I think Garth used the Grayhill 87 series keys for his workbench computer. Take a look here:

https://www.mouser.com/datasheet/2/626/ ... 334536.pdf

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Regards, KM
https://github.com/floobydust

Wow! I think that's what I want.

I found some keypads on eBay for $3 or so. Not too bad.
However, no interface schematics or model numbers. So I will have to map it out myself. No biggie.

I was thinking of building a "KIM-1 LIKE" trainer computer as my next project. I think with those keys, I could just print out the letters and make it anything.

Something like this would be awesome:



Basically, a 4x4 keypad with a 1x4 keypad next to it for function keys.

I don't know why, but there's something about those simple "trainer" computers that really attract me. Of course, calling them trainers is a little insulting considering they can do so much more.

My plan would also be to add a 4x20 LCD screen to it and a basic monitor.

Thanks!!

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Cat; the other white meat.

https://www.digikey.ca/product-detail/e ... ND/8702491

https://www.digikey.com/product-detail/ ... ND/4694446

Brad

The Grayhill 87's are nice, but like any of the nice keypads, have gotten very expensive, so be ready for that. They've been made for decades. (I like such stability!) The transparent caps are easy to remove (but they don't come out accidentally), and you can print your own labels to go under them. They go in increments of half inch square, side-to-side and end-to-end stackable without needing any space between them, and they have their pins spaced such that they go nicely into standard perfboard with holes on .100" centers. The sides of the switches are square and vertical, making it easy to cut tightly fitting openings in ABS plastic boxes and end up with the keyboard flush with the top surface of the box.

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http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

Yes. Those are perfect. I've already added them to my wishlist at Mouser. But yeah...looks to be around $35. Yikes. I tried eBay but they are expensive there too.

Oh well, I wasn't looking for the cheapest.

I thought about using tactile switches with the lettering printed on the silk screen. BUT, that just screams cheap to me.

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Cat; the other white meat.

Depending on your needs, printing the keys and legends onto light card stock and then putting a card overlay on top of tactile switches can work quite well. You can cover with book tape to get some protection against wear and spillage. It ends up a bit like a membrane keyboard but with a more positive action, and completely customisable legends.

On ebay you can get Cherry MX replacements that seem to be pretty good for the price (5 for < $2). I made up a keyboard with them a few years back and they are still working as new. As well as a full set of fitting keycaps (enough for a full keyboard) for about $12 (you'll have a ton left over) and a custom PCB to mount them on (10 for $5) from JCLPCB OR PCBWAY.

You can make exactly the keypad you'd like that way, including being able to select how much tactile feedback you'd like.

If you're a lazy programmer a 74C923 makes a great 20 key decoder.

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Bill

Recently I was browsing through Jameco's "Clearance Center" and in the Electromechanical section I noticed lots of high-quality switches (eg: C and K) at much less than the usual cost. This includes pushbutton switches which could be used to make a keypad although it's not their intended application.

Also present, FWIW, are lots of toggle and rocker switches of the momentary type which would be perfect for anyone wanting to make an old-style "front panel" interface with bit switches. Just thought I'd pass that on!

The membrane keypad on my KIM-1 is worn out to the point of being almost unusable. It served its purpose at the time, but it's not something that'll endure huge amounts of intensive use.

I used a Grayhill keypad on one of my projects, and found it very nice to design and build with. I don't have an opinion on its durability. Unlike the keypad on my KIM-1, this one never got much use.

-- Jeff

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In 1988 my 65C02 got six new registers and 44 new full-speed instructions!
https://laughtonelectronics.com/Arcana/ ... mmary.html

It gives me a warm feeling to think of a KIM-1 with a well-used keypad...