It was a wonderful thing when ASCII was extended to include lower-case characters.
Unfortunately, though, when keyboards were expanded to include additional space for the extra special characters included in the 94 printable characters of the new extended version of ASCII, usually the RETURN key and the BACK SPACE key became hard to reach.
This problem, of course, was (finally!) largely solved with the arrangement of the 101-key U.S. version of the Model M keyboard by IBM. It only took twenty years: lower case was added to ASCII in 1967, and the IBM Personal System/2 came out in 1987 (although the keyboard had appeared two years earlier on some more exotic systems).
However, in my opinion, even the Model M 101-key arrangement is not an ideal solution: here is what I wish had been done starting from 1967:
Of course, while using the CTRL key to access additional printable characters - and additional control characters - for this typewriter-pairing arrangement works well enough for the basic U.S. ASCII character set, serious problems could be encountered even with languages like German and French, with accented characters, never mind languages like Ukrainian or Armenian with larger alphabets.
When working on this diagram of my ideal keyboard, I thought further about the problems it could have. So I moved the BREAK key to the left side to make the design more compact. I included a RUB OUT key, as there was no good location for the DEL control character.
One notion I had long thought useful for keyboards was that when CAPS LOCK was on, shifting letters should produce additional special characters useful in computer programming or mathematics, instead of lower-case, which is kind of useless. I would include this feature here.
Also, if a CODE key is desired (like the Alt key on a PC) there's room for it on the left of the space bar.
But what about the AltGr key, which is the solution for languages with accented chracters and larger alphabets?
Well, I came up with a sneaky solution.
For those languages, the CTRL key - note that there's a right-hand CTRL key as well, since that key is now more important - becomes the AltGr key.
Hey, wait a moment! What if you need to enter an ACK or FF control character from the keyboard?
Well, I came up with this sneaky solution: CTRL becomes AltGr... except if CAPS LOCK is on. When CAPS LOCK is on, the CTRL key allows control characters to be typed instead.
For languages like Armenian, where the digits 0 through 9 would have to be normally accessed using AltGr on a keyboard like this, my solution would be to make them accessible with SHIFT when in CAPS LOCK mode, rather than relegating them to CTRL-SHIFT.
