• Please review our updated Terms and Rules here

Do you know where to find this Keyboard? Pics

luckybob

Veteran Member
Joined
Feb 3, 2009
Messages
1,326
Location
denver
I was right. They look the same. Granted the color is different but I doubt that matters. I also have the black/silver version of the ti 99/4a and I would bet all the tea in china it used the same switches as I have pictured here.

picture 1

picture 2
 

atod

Experienced Member
Joined
Oct 14, 2010
Messages
303
Location
New York, NY
Thanks for the pictures! I just purchased the Atari 800 keyboard for about $37 (w/ S&H). It looks like the Atari key format may match up better. Who knows, maybe that will allow me to cut the Atari keyboard to size. I'll post the results.

Someone was looking for missing Atari keys. Please send me a private message with the address they should be sent to.

Thanks
 

Mr.Amiga500

Experienced Member
Joined
May 27, 2008
Messages
432
Location
Canada
I was right. They look the same. Granted the color is different but I doubt that matters. I also have the black/silver version of the ti 99/4a and I would bet all the tea in china it used the same switches as I have pictured here.

picture 1

picture 2

Wow, that's weird. I thought you were talking about the silver/black TI-99/4a, but still... it's strange that they switched to an older style switch when making a newer cost-cutting model. I bet those switches were cheaper to make than the Alps-style ones they originally had.

Thanks for the pictures.
 
Last edited:

atod

Experienced Member
Joined
Oct 14, 2010
Messages
303
Location
New York, NY
I ended up transporting an Atari 800 keyboard switch to the ADM keyboard. I drilled out both keys with a 1/4" long hole saw bit. It lines up just right. I then used epoxy to hold the new key in. The only issue was the Atari 800 keyswitch is about 1/4 cm higher then the original ADM keyswitch. This results in a higher key. I carefully used an Xacto knife to "shave" off the top of the yellow plastic. In addition, I had to shave the bottom of the key associated with this keyswitch. I should have never used a dremel to try and get at the corroded contacts. Hope that helps someone in the future.

I have all the keys so once I extend the broken contacts with leads, this should be in business.

Note : If you have an ADM-3A I highly suggest you inspect it for this oil like goo. It's the polyvinyl adhesive and must contain some sort of water because it corroded parts of the keyboard and motherboard. I cleaned it with alcohol. It comes from the monitor's old adhesive that hold the lens in place. There is a writeup to fix that also.

photobbu.jpg
 

Druid6900

Veteran Member
Joined
May 7, 2006
Messages
3,809
Location
Hamilton, Ontario, Canada
The picture of the original keyboard you showed looks an awful lot like an old Cherry keyboard, the same type that the early Tandy Model Is used to use. I've been inside enough of them to be 99% sure since we used to have to take off every keycap on some units and bend one "finger" of the split contact forward to prevent "key bounce".

I probably have a couple of keyboards around in my Tandy parts.
 

atod

Experienced Member
Joined
Oct 14, 2010
Messages
303
Location
New York, NY
Thanks. If you have an early Tandy Model Is keyboard I would be interested. I soldered on new terminals where the old ones corroded. I then performed a continuity test open then closed. I found two more keys were broken. The finger contact corroded off it's base on the bottom for each key. Now I'm in the process of "transporting" two more keys from the Atari to the LSI. Unfortunately, this requires a delicate epoxy job and also shaving the yellow colored box a few millimeters because it is too tall. The key must also be shaved a small amount to allow everything level. Here are some pics of where I'm at.





 

atod

Experienced Member
Joined
Oct 14, 2010
Messages
303
Location
New York, NY
The picture of the original keyboard you showed looks an awful lot like an old Cherry keyboard, the same type that the early Tandy Model Is used to use. I've been inside enough of them to be 99% sure since we used to have to take off every keycap on some units and bend one "finger" of the split contact forward to prevent "key bounce".

I probably have a couple of keyboards around in my Tandy parts.

It is very close to the Tandy Model 1, but not 100%. A few keys on the right are missing. See pics below

ADM-3A
KB_Terminal_ADM3A.svg


Tandy
trs-80top.jpg
 

RetroHacker_

Veteran Member
Joined
May 21, 2006
Messages
573
Location
Niskayuna, NY
It is very close to the Tandy Model 1, but not 100%. A few keys on the right are missing. See pics below

Well, that particular Model 1 hardly counts - it's been modified with some other keyboard. Probably as a method to get rid of the horrible keyboard bounce the early Model 1's had....

-Ian
 

atod

Experienced Member
Joined
Oct 14, 2010
Messages
303
Location
New York, NY
Well, that particular Model 1 hardly counts - it's been modified with some other keyboard. Probably as a method to get rid of the horrible keyboard bounce the early Model 1's had....

-Ian

Thanks. It's still missing keys to the right. Perhaps the keyswitches are there but not used. If someone has an open Model 1, can you please post a picture of the entire keyswitch assembly? Thanks

ModelI-1L.jpg

model1xbig.jpg
 

atod

Experienced Member
Joined
Oct 14, 2010
Messages
303
Location
New York, NY
I wasn't thinking of it as an exact replacement, more a place to get the right keyswitches from.

Ok. From looking at the Model 1, it looks more like the ADM then the Atari 800 keyboard does. The Atari 800 keyswitch yellow parts are slightly higher and need to be shaved down.
 

atod

Experienced Member
Joined
Oct 14, 2010
Messages
303
Location
New York, NY
I finished replacing three keyswitches (hole saw method) and soldered all the leads to each terminal that broke due to corrosion. All the switches check out ok on/off during continuity test.

I was going to solder the keyboard back to the motherboard and then came disappointment. I would need all the stars aligned just right for these new leads to all slide into the PC board holes at once. The original keyboard had thick terminal leads that were probably bent to specification so they were always aligned. My new leads bend easily and are all over the place.

Does anyone have suggestions for fixing this? I'm thinking of using wire wrap between the keyboard and the top side PC board. Then tuck it under the keyboard hoping it doesn't present a clearance problem. Alternatively, routing all the wire wrap to the bottom for maybe more clearance. This would essentially be connecting the keyboard through wire. Perhaps I should be using different wire then wire wrap?

Alternatively, using thin gauge bare wire (28 AWG?), maybe in 14" lengths soldered to each terminal. Then pull the wire through the hole, tighten the slack and solder.

Any ideas appreciated

photo11nr.jpg

photo12fs.jpg
 
Last edited:

RetroHacker_

Veteran Member
Joined
May 21, 2006
Messages
573
Location
Niskayuna, NY
Alternatively, using thin gauge bare wire (28 AWG?), maybe in 14" lengths soldered to each terminal. Then pull the wire through the hole, tighten the slack and solder.

This one. It's what I've had to do when replacing the base on a picture tube. Fortunately, you should only have to do the three switches you replaced, as the factory ones should be fairly easy to align.

But, I wouldn't solder the keyboard on just yet. Get the terminal's logic board working, and verify that all the key positions work (jumper it with a little bit of wire, see if the key registers), that way you know all the tracks are good and nothing else was damaged. You don't want to have to take the keyboard off again to fix a trace underneath it.

-Ian
 

atod

Experienced Member
Joined
Oct 14, 2010
Messages
303
Location
New York, NY
This one. It's what I've had to do when replacing the base on a picture tube. Fortunately, you should only have to do the three switches you replaced, as the factory ones should be fairly easy to align.

But, I wouldn't solder the keyboard on just yet. Get the terminal's logic board working, and verify that all the key positions work (jumper it with a little bit of wire, see if the key registers), that way you know all the tracks are good and nothing else was damaged. You don't want to have to take the keyboard off again to fix a trace underneath it.

Thanks Ian. Actually, about 80% of the terminals broke due to corrosion. The polyvinyl adhesive leaked all under the keyboard and probably sat there for over a decade. So almost all the terminals will have long bare wire hanging from them. It's going to be daunting figuring out which wire goes into which component hole but I think it can be done.
 

RetroHacker_

Veteran Member
Joined
May 21, 2006
Messages
573
Location
Niskayuna, NY
So almost all the terminals will have long bare wire hanging from them.

You also need to be really careful that when you solder your extended leads to the board, you don't simultaneously unsolder them from the keyswitch from the heat. Be sure your lengthened terminals are very securely soldered/crimped onto what's left of the old terminals, and to solder quickly to the board.

-Ian
 

atod

Experienced Member
Joined
Oct 14, 2010
Messages
303
Location
New York, NY
You also need to be really careful that when you solder your extended leads to the board, you don't simultaneously unsolder them from the keyswitch from the heat. Be sure your lengthened terminals are very securely soldered/crimped onto what's left of the old terminals, and to solder quickly to the board.

-Ian

Yeah, I validated that, but now I have to do it all again using wire.
 
Top