Chicklet keyboard

Hardware questions and modifications

Chicklet keyboard

Postby geoffdaddy » Wed Feb 11, 2015 8:04 pm

Does anyone have schematics for the chicklet keyboard in digital form? My keyboard has quit working... except when I press around certain areas of the PCB. Trying to figure it out right now. In the meantime, I'm using the "enhanced keyboard" and have found that I really like the chicklet one better. ;)
PCjr: 10MB RACore 01 hard drive expansion, Hotshot 640kB RAM expander, optical mouse, Xircom PE3, speech sidecar.
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Re: Chicklet keyboard

Postby geoffdaddy » Wed Feb 11, 2015 8:19 pm

Okay, I figured something out....I isolated it to one chip on the board... resoldered it and still no dice. However, if I hold down a key, and lightly swipe a finger along the pins of the part, one the side facing the back of the keyboard, it will work...until I lift the key.

The chip is a MC14068 which is an 8-input NAND. I guess the part is marginal now? Used to work just fine until last week.
PCjr: 10MB RACore 01 hard drive expansion, Hotshot 640kB RAM expander, optical mouse, Xircom PE3, speech sidecar.
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Re: Chicklet keyboard

Postby Trixter » Wed Feb 11, 2015 8:46 pm

I combed the hardware maintenance and service manual and couldn't find anything; but, in case it's helpful in other ways, I scanned and uploaded it for you: ftp://ftp.oldskool.org/pub/misc/Hardwar ... ervice.pdf

You're right about the chiclet keyboard -- it has better tactile response. It only takes an hour to get used to it, and it's better than the second "pro" keyboard they came out with.
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Re: Chicklet keyboard

Postby Trixter » Wed Feb 11, 2015 8:47 pm

You're all insane and trying to steal my magic bag!
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Re: Chicklet keyboard

Postby geoffdaddy » Thu Feb 12, 2015 6:12 am

Thanks for the pdf... I didn't have that one yet.

Yeah, I think in retrospect that IBM's biggest mistake with the original keyboard was not putting the key labels on the keycaps themselves. I think if they had done that people might have been more receptive to it. As it is, if you're not an expert typist if you have the keyboard at a normal position relative to my sitting position at least, you can't really see which key is which.

Looks like I might have to replace that one part. I resoldered it again and that's definitely not it. Batteries are definitely good.
PCjr: 10MB RACore 01 hard drive expansion, Hotshot 640kB RAM expander, optical mouse, Xircom PE3, speech sidecar.
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Re: Chicklet keyboard

Postby jmetal88 » Thu Feb 12, 2015 10:09 am

You can take the PCB out of your working 'pro' keyboard and put it inside the 'chiclet' keyboard. I did that, but in reverse since I prefer the full-sized key caps. After seeing posts like this, though, it's making me wonder if I should swap them back and try getting used to the 'chiclet' keyboard again.
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Re: Chicklet keyboard

Postby Trixter » Thu Feb 12, 2015 11:08 am

When I was researching the PCjr for my presentation, I bought into all of the hype I found in the press about the keyboard being crap. It was only after I set up a chiclet keyboard and started trying to use it that I realized the keys were less flimsy and had a better tactile response. It's hard to explain in words, but the later "pro" keyboard has very thin, hollow keycaps that sometimes squeak (audibly!) as plastic rubs on plastic. It feels cheaper than the chiclet keyboard.

A legitimate criticism of the chiclet keyboard, apart from the condensed layout (which people got used to 20 years later in sub-notebooks) is that the smaller keys have less surface area for your finger to strike, so your fingers are slipping off of them as you type. But you can get used to that after an hour or so.
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Re: Chicklet keyboard

Postby geoffdaddy » Thu Feb 12, 2015 12:06 pm

jmetal88 wrote:You can take the PCB out of your working 'pro' keyboard and put it inside the 'chiclet' keyboard. I did that, but in reverse since I prefer the full-sized key caps. After seeing posts like this, though, it's making me wonder if I should swap them back and try getting used to the 'chiclet' keyboard again.


Nice! Thanks for the tip, I didn't think to try that. I'll definitely go that route then. My enhanced keyboard is sub-par quality anyway... really yellowed plastics, missing the badge, and the key labels on the keycaps have bled/smeared into the surrounding plastic on the keycap. Doesn't look too great.

Conversely, I can say that the PCB on the chicklet keyboard is a bit shabby. There's a few areas of corrosion on it.
PCjr: 10MB RACore 01 hard drive expansion, Hotshot 640kB RAM expander, optical mouse, Xircom PE3, speech sidecar.
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Re: Chicklet keyboard

Postby geoffdaddy » Fri Feb 13, 2015 8:49 am

Well, I did the guts transplant on my keyboards last night and it was successful. Thanks for the tip, jmetal!
PCjr: 10MB RACore 01 hard drive expansion, Hotshot 640kB RAM expander, optical mouse, Xircom PE3, speech sidecar.
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