This is a ten-year old article. Looking it over, it is still right on. The older keybvoards were really, really bad.
http://www.pcworld.com/article/139100/the_10_worst_pc_keyboards_of_all_time.html

Look at this:

It even gets worse! Click on link above for a visit to the crazy keyboard history.
 
I couldn't get the site to work. Stays on the intro page, next doesn't work, trying to click the arrows doesn't do anything, etc.


Anyway, my vote is for the Atari 400:

https://upload.wikimedia.org/wikipedia/commons/thumb/f/f7/Atari-400-Comp.jpg/2560px-Atari-400-Comp.jpg

Here is the link again.

http://www.pcworld.com/article/139100/the_10_worst_pc_keyboards_of_all_time.html

Yeah,the Atari was bad. An three was a Tandy colour computer that was horrible.
http://www.pcworld.com/article/139100/the_10_worst_pc_keyboards_of_all_time.html#slide6

[attachment deleted by admin to conserve space]Neither link WORKS for me, I think MAYBE it only works for those with a subscription to the site?

My vote is for any of those so called ergonomic keyboards, they are terrible.Sorry about the links. When  that kind of thing happens,  one could try a proxy to see if another route works better.

In that list the IBM jr was  listed as the worst ever.
From the article:
PCWorld Worst Keyboards
10. Commodore 64 (1982)
9. Timex Sinclair 2068 (1983)
8. Commodore PET 2001-32-N (1978)
7. Texas Instruments TI-99/4 (1979)
6. Tandy TRS-80 Micro Color Computer MC-10 (1983)
5. Atari 400 (1979)
4. Timex Sinclair 1000 (1982)
3. Mattel Aquarius (1983)
2. Commodore PET 2001 (1977)
1. IBM PCjr (1984)

I had a Sinclair. Gave it away.  Those rubbery, calculator type keyboards in several early computers at 80's were really bad. But I dont understand at all, how Commodore 64 is on the list (10th worst) I strongly DISAGREE!
And I have typed many, many program listings, used wordprocessor and spreadsheet with my C64.

I would say, any relatively new el-cheapo keyboard that has a 'spongy feel' when pressing the key is worse, and what's also annoying, is that nowadays the manufacturers are making the keyboards smaller (people dont have space on their desks anymore?) so the keys are too close to each other.
At work I have a HP keyboard from circa -08, that is clearly 'downsized', and many times after I've once again hit two keys at the same time, at the end of the day I've been very close to yanking that keyboard off, and to bring next day some older, real sized keyboard from home to replace it.

Oh, and yes, those 'ergonomic keyboards', as mentioned before, they are really awful.I disagree with the comments on ergonomic keyboards.  I have a Microsoft Comfort Curve Keyboard 2000 that I've used for several YEARS now and I like it.  But, I guess this keyboard is only slightly ergonomically shaped, compared to other ergonomic keyboards.