Atari 800 (not XL) keyboard basics

[ACML]

Atari made a few versions of the 800 keybaord during its five year production run. Each has its quirks, but all can be serviceable after 30+ years.

 

1) The original Hi Tek keyboards are very rare, I've never seen one, and they have a male ribbon cable connector like the 400 keyboard. These were only on the very first 1979 800's. Really can't comment on this one much.

 

2) The majority of 800 keyboards are the excellent mechanical Hi Teks that have white plungers. As stated, they are mechanical switch keyboards and many still work wonderfully and will continue to for many years. They do have one flaw. Due to repeated pounding of the spacebar, the load (force) is transmitted to the solder pad on the PCB. After many thousands of cycles, the solder pad at location 57 on the back of the PCB fails and the contact pin falls out leaving with a bad spacebar. You just need to reinsert a wire in the hole in the solder pad at location 57, experiment a little with a multimeter to find the position that restores continuity and re-solder the lead. This is probably the best made keyboard Atari ever made.

 

3) For a short while Atari used mylar membrane keyboards made by Mitsumi. They look feel and are constructed just like the 1200XL keyboard also made by Mitsumi. If you can find a mitsumi keyboard today that works, its a miracle. Everyone I've ever encountered had a few or no keys working. They can be easily identified as they are darker in appearance and have a distinctive glossy look. These, when they work, are awesome as they are not mechanical switched and feel smooth, but lack feedback. They can be fixed and will have to be, count on it, using the same procedure BOB1200XL has on RETROBITS.net.

 

4) The last run of keyboard was made by Stackpole, which have yellow plungers and are mechanically switch like the Hi Tek. These will last a long time and are reliable except, they too, have a flaw. The yellow plastic plungers all start to crack at the corners, even if not used. This causes the the keys to seat too deep and either the loose fit causes the key top to pop off or the key binds and sticks in the down position. The only way to fix these is to replace the yellow spacers. You just need to be careful you don't bend the fragile little gold plated contact fingers in the middle of the mechanical switch.

 

The Hi Tek and Stackpole will be the most reliable over time, but the Mitsumi has its rewards if you can revive them.

Edited February 12, 2014 by ACML

[Sub(Function(:))]

Also regarding the 800 Keyboards

 

I have witnessed and heard that the white plastic used on these keyboards can become brittle, and break, with age (or heat over time). This eventually leads to the keycaps popping off.

 

But I will say in good condition these keyboards have a really good feel to them.

Edited February 12, 2014 by Sub(Function(:))

[ACML]

Just thought I'd revisit the subject now that I have a little more experience working with and restoring 800 keyboards. I definitely have my preference after fixing several.

 

1) The best keyboard in my opinion for the 800 is the Mitsumi. It was made by the same company that made the 1200XL keyboards and they have the same feel. They are smooth, quite and the most serviceable. The Mylar conductive tape will have to be removed and you have to rebuild the 9 or so terminal traces with conductive paint.

 

2) Second on my preference is the Hi-Tek (white plungers). A very good mechanical keyboard, but has a major flaw. The spacebar will eventually fail and the repair can be straight forward or a pain in the ass. Has a mechanical noise not present in the Mitsumi.

 

3) Third, only because I can't make it tenth, is the Stack Pole (yellow plungers). Garbage, plain and simple. Stay away from these. The yellow plungers always crack, even if not used. Yes, NOS Stackpoles will have cracked plungers. It causes the key caps to fall off. Plus the ribbon cable is horrendous. It will cold work itself in just a few bends and break, lose continuity. A major pain to fix once the ribbon leads start cold working. I hate these keyboards with a passion. Bought one brand new from Best and it failed after trying to install it a couple times (ribbon cold working failure). Not Best's fault, Brad just sells them. It's the only ones you can get now NOS.

Edited September 29, 2015 by ACML

[vfrvulcan]

Thanks ACML, spent ages searching for the correct terminology to fix my keyboard and your description of the spacebar problem on the Hi-Tek was perfect.

 

Three hours messing around soldering/de-soldering/soldering and I have my spacebar working again. Guess you can file that one in the 'pain in the ass' dept :-)

 

So easy holding a wire in there and checking continuity, but holding it there and soldering was a different story.

 

Once again, many thanks for your help/info.

[simbalion]

I have one of the stackpole units from Best and so far it works good. One rule I use with all this old stuff is to try and not to disturb ribbons and cables too much. Age gets to all of it over time, especially when mixed with heat.

[Bryan]

The Hi-Teks aren't that rare. I've owned a few of them over the years. At one time I had a supply of OEM Stackpole keyboards for another (unknown) system and I used them as a source of plungers.

[Level42]

Great information !

 

However.......this thread would be _brilliant_ if there were some pictures to show all the different versions

 

Any idea which one the PAL 800 had ? My PAL 800 works fine (after replacing one RAM chip) but the keyboard is dead...completely....

[800_Rocks]

On 1/21/2016 at 11:28 AM, Level42 said:

However.......this thread would be _brilliant_ if there were some pictures to show all the different versions

 

Better (5 years) late than never ?

 

Here they are in order from best to worst (according to ACML above... and I agree with his ranking)

1) Mitsumi - The one in this picture is very dirty but here's the keyboard.  The other pictures show how you repair the original mylar (aka membrane) if your keys are not working.

Here's the underside, notice the brown color 'board' with 17 tiny screws (two are hidden by the ribbon cable)

Two tiny screws hidden by the ribbon cable including one I had to 'dig for' under the foam sticky pad that hold the ribbon cable to the brown board.

 

Once all the tiny screws are removed you find the mylar (aka membrane)

Removing the membrane is difficult and takes a lot of patience and finesse.  This one took me about 45 minutes to carefully remove as the membrane tends to stick to the PCB, especially where the 17 little screws held it so tight to the PCB over the years.  Some use heat, some use 99% Isopropyl Alcohol, I've been successful using only a very tiny flat head screwdriver to 'coax' the sticky bits away from the PCB with the mylar mostly intact (see the few tiny white bits of mylar that tore off and stuck to the PCB).  Get all of these white bits of torn mylar removed.  Clean the entire PCB with 99% isopropyl alcohol especially each of the gold circular points.

You must remove the tape and clean up the glue/paste that was originally used to adhere the mylar contacts to the PCB contacts.  In this next picture the tape is sitting above and I have removed all of the glue/paste (it was difficult, I used a plastic guitar pick to scrape it away, then used the 99% Alcohol to remove all the grime to get the gold PCB contacts very clean and shiny).

Below is the underside of the mylar that makes contact with the PCB.  I have 'painted on' new leads using the product 'Bare Conductive Electric Paint'.  This also takes a lot of finesse.  Keep the paint in it's 'lane', keep all the leads the same thickness, let them dry completely before reassembling.  Just put the mylar back on the PCB, align it well, put the brown board back on top and put all 17 tiny screws back in.  Hopefully you are back in business now!!

 

2) HI-TEK - only 1 picture of the underside

 

3) Stack Pole - see the yellow sleeves, 2nd picture shows details including many cracks in corners of the sleeves

Below is the underside of the Stackpole

 

 

 

Edited February 21, 2021 by 800_Rocks

[bfollowell]

 

Someone is selling Hi-Tek/Stackpole repair kits on eBay. They consist of 3D printed parts, but I'm having trouble understanding how they work or what they do. I'm assuming they're supposed to correct the issue of what I call the key switch sleeve splitting at the corners, but the part looks like it's supposed to attach to the underside of the keycap, so I'm still not seeing how it helps.

 

If I understand the keycap and the key switch sleeve, if I remember correctly, the stem of the keycap slides inside the key switch sleeve. There is a picture on the page of the bottom of a keycap, but I'm having trouble seeing where this 3D printed part goes. It doesn't help that I haven't done a lot of keyboard repairs in general, or that these are my first two 800s in over 35 years.

 

Are any of you guys able to better tell what how these work or what I'm missing?

 

Thanks.

 

https://www.ebay.com/itm/166147437154?
 

[bfollowell]

3 hours ago, bfollowell said:

 

Someone is selling Hi-Tek/Stackpole repair kits on eBay. They consist of 3D printed parts, but I'm having trouble understanding how they work or what they do. I'm assuming they're supposed to correct the issue of what I call the key switch sleeve splitting at the corners, but the part looks like it's supposed to attach to the underside of the keycap, so I'm still not seeing how it helps.

 

If I understand the keycap and the key switch sleeve, if I remember correctly, the stem of the keycap slides inside the key switch sleeve. There is a picture on the page of the bottom of a keycap, but I'm having trouble seeing where this 3D printed part goes. It doesn't help that I haven't done a lot of keyboard repairs in general, or that these are my first two 800s in over 35 years.

 

Are any of you guys able to better tell what how these work or what I'm missing?

 

Thanks.

 

https://www.ebay.com/itm/166147437154?
 

 

OK, it's all clear now. These are thin collars that you glue around the top of the plungers, what I was referring to as the key switch sleeve. They're thin enough to still allow the plunger to be fully depressed, while holding the top part of the plunger together and giving it extra support in case it has already split, or to keep it from splitting.

 

I'm considering ordering two sets, because my newly purchased 800s both have many, if not all of the plungers on the Hi-Tek keyboards exhibiting this problem.

 

 

[bfollowell]

I ordered both of the seller's remaining two sets. I'd say he will print more and restock.

 

He also has a set of replacement plungers that he sells. I'll put the link below if anyone is interested in giving t hem a try. In case the links go dead, the seller's ebay username is gkraemer.

 

I'll write back with a review of the collars once I receive them, install them, and have time to give them a good test.

 

 

https://www.ebay.com/itm/155822218647