Atari 800 Replacement Keyboard

[Multifarious Industries]

Like many of you, I have a couple of Atari 800s with keyboards that aren't working for various reasons. I didn't like the idea of buying a NOS one from ebay and having it fail for the same reasons as the ones I have, but there weren't any other available options. Then it occurred to me that since mechanical keyboards are now a hobby, maybe I could make my own. My goal was to make a drop-in replacement keyboard that didn't require any modifications to the Atari, used the original key caps to maintain the original look, and should be easy enough for most maker types to reproduce.

 

Luckily, the 800 keyboard is pretty simple. Its just a matrix of switches with no diodes or microcontrollers needed. So I mapped out the matrix using a multimeter and got to work in KiCad designing the PCB. A few weeks later, my newly designed board was delivered from the board house in China.

 

 

After soldering in 57 Cherry MX black switches and a pin header, I hooked the new keyboard up to the Atari with an IDE cable for testing, and success! The PCB worked first try!

 

 

The original keyboard mounts at an angle and is very recessed compared to modern keyboards. As I had a Stackpole keyboard to use as a template, designing 3d printable mounting brackets was pretty easy. I also integrated a support to run along the top edge of the PCB and limit the amount of flex it had when typing. 

The adapters to use the original keys, however, were much more challenging. The dimensions of both the original keycaps and the Chery MX switches required pretty tight tolerances, and since I needed an adapter for every key, I wanted them to print without supports and without needing tedious cleanup. After dozens of failed attempts, I finally got something that would fit snugly and could be printed in bulk on my 3D printer. 

 

Here's the finished installation:

 

The keys have a little bit of wiggle, because of the extended height of the keycap/adapter/switch combination, but it's very usable and the modern switches should last a very long time. 

For those of you who'd like your own, I've uploaded all the files for the PCB and 3D prints to github and have included some instructions. https://github.com/multifariousindustries/Atari800Keyboard

If you make one, please let me know what you think! 

[adam1977]

That's great, well done ?

[Sugarland]

A huge step in the right direction! Excellent news. Thank you!!  I like the IDE cable ?  

[Justin Payne]

Someone just did this with the 130xe and I think this is a wonderful idea. My scanner gave up the ghost but I figured I could find another and scan mine and then do what you did for the 1200xl. It would be nice to have a collections of these layouts just in case you want to go with this solution instead of dropping $40 into another Mylar sheet.

[RodLightning]

Brilliant and long overdue.  Perhaps at some point someone will offer to sell a kit with brackets, key cap adapters and circuit board for those of us without access to a 3d printer.  My 800 has the white plungers starting to crack, but is still usable with only a few loose keycaps.  This is still a project I might consider later on though.

 

I imagine the cherry switches might be pricey unless one found a donor keyboard with the correct parts.  I am interested in how much wiggle is present in this new design.  Is it enough to interfere with speedy touch typing?

[_The Doctor__]

gluing the adapter to the switch post and NOT the keycap got rid of some serious wiggle... ymmv

[Multifarious Industries]

17 hours ago, RodLightning said:

Brilliant and long overdue.  Perhaps at some point someone will offer to sell a kit with brackets, key cap adapters and circuit board for those of us without access to a 3d printer.  My 800 has the white plungers starting to crack, but is still usable with only a few loose keycaps.  This is still a project I might consider later on though.

 

I imagine the cherry switches might be pricey unless one found a donor keyboard with the correct parts.  I am interested in how much wiggle is present in this new design.  Is it enough to interfere with speedy touch typing?

Thanks! I've considered making more to sell, but it would depend on the demand. The cherry switches were actually pretty reasonable. I got 60 of them for $45 online. My hope was to make them cheaper to build than an OEM keyboard from eBay that would eventually have the same problems. I definitely kept it under $100 and if I was making a larger batch of them I could get the cost down even more. 

 

As for touch typing, I type around 60 wpm on a modern keyboard and for me, the limiting factor was not the wiggle, but the slightly different placement of the keys that slowed me down. 

[Multifarious Industries]

18 hours ago, Justin Payne said:

Someone just did this with the 130xe and I think this is a wonderful idea. My scanner gave up the ghost but I figured I could find another and scan mine and then do what you did for the 1200xl. It would be nice to have a collections of these layouts just in case you want to go with this solution instead of dropping $40 into another Mylar sheet.

If you are doing a brand new PCB like I did, I'm not sure you need a scanner? I figured out which keys were connected to which pins on the connector, and routed all the traces myself. They don't need to match the original ones. 

[Justin Payne]

On 3/12/2021 at 2:20 PM, Multifarious Industries said:

If you are doing a brand new PCB like I did, I'm not sure you need a scanner? I figured out which keys were connected to which pins on the connector, and routed all the traces myself. They don't need to match the original ones. 

I just expected that scanning it would give me a idea of placement of the keys and wouldn't require me to measure each position since I could add measurement lines in addition to what I'm scanning OR just use it as an overlay. I've never done something like this so this was just the first way that came to mind.

[Multifarious Industries]

That makes sense. I'm not sure about other models, but for the 800, they used the same standard spacing still used on keyboards today. About 19mm or 3/4" is 1 unit. Most of the keys are 1 unit, with the tab, return, and shift being 1.5 units, the left shift is 2 units and the spacebar is 9 units. I used a 19.05mm grid and it worked great. I laid it all out in kicad and then printed it out to make sure it fit where the original keyboard went before ordering the PCBs. The only real measuring I did was for the outline of the PCB and to figure out how tall to make the key adapters to keep them at the same height as the original. 

[Krenath]

The official key spacing being in imperial measurements rather than metric or mils, I switched my PCB software over so that I could further divide the placement grid.

In imperial measurements, a key space is 3/4" by 3/4".  

In order to get the right key offsets and wider key sizes, you basically need increments of 1/4 key width, and for some reason my PCB software wouldn't let me divide the 19.05mm value into grid squares 1/4 that size because it didn't like the number of decimal places.  

With a grid size of 0.1875" I found I could easily snap the key objects to the grid at exactly the spacing I needed, and then flip back over to mils or mm for everything else.

The top two rows are 15 units wide, so 11 1/4 inches total width.  
The next two rows are a half a key unit narrower, indenting 1/4 unit on either side.  So, 10 7/8" wide.
The spacebar is 9 units wide, so 6 3/4"

(My keyboard is different, as I found that it seems difficult to source a 9U spacebar, but I did find a 4U, which left me room for 5 additional keys (and potential room for more if I wants a 2U spacebar or just wanted to use keyswitches to stabilize the 4U bar.)
 

 

Edited March 23, 2021 by Krenath

[spamh8r]

If this ends up being a kit- please add me to the list-- even if it doesn't, any suggestions on where to get the PCB at a reasonable price? It will take forever with my tiny 3d printer for the additional parts, but I can get the switches reasonably (can find generic blue switch keyboards on Amazon for around $20 on sale pretty regularly).

[StickJock]

What do you think about the idea of swapping the Atari & R-Shift keys?  Atari did this with the XL & XE series.

Years of using the 800 back in the 80s taught me to basically never use the right shift key, since I would frequently hit the Atari key instead of the Right Shift key.  Even now, nearly 40 years later, I still never use the right shift key when typing.

 

[Multifarious Industries]

On 3/23/2021 at 12:42 PM, spamh8r said:

If this ends up being a kit- please add me to the list-- even if it doesn't, any suggestions on where to get the PCB at a reasonable price? It will take forever with my tiny 3d printer for the additional parts, but I can get the switches reasonably (can find generic blue switch keyboards on Amazon for around $20 on sale pretty regularly).

I found JLCPCB to be the cheapest. It was about $17 for 5 boards (which I think is the minimum?) and the shipping was about that much again. I looked at some of the places in the US, thinking that I'd be able to get them faster, but some wanted up to $200 for 5 boards, so I went with the significantly cheaper/slower route. Most PCB places will let you upload a zip file and get a quote so you can use the one in the repo. 

[toddtmw]

On 3/23/2021 at 12:42 PM, spamh8r said:

(can find generic blue switch keyboards on Amazon for around $20 on sale pretty regularly).

Would you be willing to link to one that you think will work?

 

Thank you.

[Multifarious Industries]

Not quite as cheap as what spamh8r was talking about, but I used these: https://mechanicalkeyboards.com/shop/index.php?l=product_detail&p=1030. $45 when you buy 60. Any cherry style PCB mount switches should fit though. 

[BillC]

2 hours ago, toddtmw said:

Would you be willing to link to one that you think will work?

I think these are keyswitches that would be compatible, they could be clones rather than made by Cherry though.

 

Edited March 26, 2021 by BillC

[spamh8r]

On 3/25/2021 at 5:56 PM, toddtmw said:

Would you be willing to link to one that you think will work?

 

Thank you.

Here's one that goes on sale for $20 fairly often-- https://www.amazon.com/gp/product/B07VNQQZFK/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

[computergui]

Just ordered my PCB's.  I'll let you guys know how it goes!

 

Thanks for publishing the info.  Atari 800 keyboards are becoming unobtainium!

[computergui]

Thanks for making this available.  Had to remove a small bit of mounting posts on the case to move the keyboard up.

 

Works perfectly!!!  Went with a blue motif and white keycaps.

 

Next restore I do, I'll look to do custom keycap legends to match the original.  Really appreciate you took the time to put this together.

 

Don

[gilsaluki]

Really cool Papa Smurf 800.

[Multifarious Industries]

@computergui Glad it worked so well for you!

 

Has anybody else built one yet? I'm curious if the adapters for the original keys are working for people. If they are, I might get some more PCBs made and make kits if people are still interested? 

[venom4728a]

I would be interested in one possibly two kits.

 

Instead of the keycap adapters maybe a replacement stem could be made to replace the stem in the key switch like was done here in the 130xe keyboard rebuild tread. This might possibly reduce the key wobble?

 

 

 

Edited September 15, 2021 by venom4728a

[kenames99]

8 hours ago, Multifarious Industries said:

@computergui Glad it worked so well for you!

 

Has anybody else built one yet? I'm curious if the adapters for the original keys are working for people. If they are, I might get some more PCBs made and make kits if people are still interested? 

I would be interested in 1 or 2 since both of my 800s have bad keyboards. thanks.

 

Ken

 

[+Spancho]

15 hours ago, Multifarious Industries said:

@computergui Glad it worked so well for you!

 

Has anybody else built one yet? I'm curious if the adapters for the original keys are working for people. If they are, I might get some more PCBs made and make kits if people are still interested? 

I would be interested in 2 kits, maybe more.