To begin this page, we will look at a keyboard that only a fortunate few have had the opportunity to use, but which only has a character set of normal size:
This is the keyboard for the Digital Equipment Corporation's Flexowriter Input/Output code, as used with both the PDP-1 and PDP-4 computers before ASCII arrived to take over. The terminal was a converted IBM electric typewriter (Model B), adapted by Soroban, but the data transmission code resembled that of a 2741. (Incidentally, a Flexowriter looks suspiciously like a Model 01 electric typewriter; doubtless, there is a story behind that.)
Another very early example of a large keyboard is the one for the Uniscope 300 terminal. The image below does not quite do it justice:
The character set used with this keyboard was achieved using the same character codes as used for normal ASCII characters; the codes we now use for lower-case characters, which may not even have yet been assigned that meaning when this terminal was designed, are the ones used for the special symbols on this keyboard: the codes it generated corresponded to conventional ASCII in this fashion:
\ m n ` o |
e f q r s < >
! " # $ % & ' ( )
1 2 3 4 5 6 7 8 9 0 *
g h t u v | a
=
Q W E R T Y U I O P -
i j w x y @ ^
A S D F G H J K L ; :
k l + p - b c
?
Z X C V B N M , . /
_ [ z ~ { d ]
I suspect software on the mainframe to which this terminal communicated translated characters for the numeric keypad, given the bit-pairing arrangement, although, as the relationship between the normal codes for those keys and those for the digits is also bit-pairing, this may not necessarily be the case.
The area on the right side with the numeric keypad and all the special characters was designed for the use of keyboard overlays, and it appears to me that this was its usual use, and the special symbols were not used as often, although I suspect they may have been used also, but for an interactive calculator rather than a programming language.
What I am always hoping for in keyboards, besides a conventional arrangement, is convenience in entering characters additional to those of 7-bit ASCII.
Now this is a keyboard, and based on the manual typewriter, yet!
But the kind of keyboard I'm really looking for would look more like this:
Programming and mathematical symbols, reached by an alternate shift, are on the right side in blue; word processing characters are on the left side in red. Dark red (and dark blue) with yellow background highlighting indicates character substitutes; normal red and blue, characters reached by an alternate shift.
Now, let us look at some of the real-life keyboards that inspired me to think in such terms.
First, here are some alternate keyboard arrangements offered by IBM for the 3277 display station. A conventional keyboard arrangement for this terminal is shown below:
IBM made more Spartan keyboard arrangements for this terminal as well. Despite appearances, terminals with this keyboard normally did not support lower-case letters. But lower-case alphabetics were included if you got this version of the keyboard:
which provided an alternate mode for entering APL characters, including a third shift by means of which the overstrikes used in APLSV, which used the overstruck characters of APL\360 plus three additional ones, could be produced as independent characters.
In our survey of large keyboards, first we will look at the next keyboard in this progression, the text keyboard for the 3277. This keyboard allowed entry of the APL character set, including overstrikes, and it also allowed direct entry of the special characters available on the TN print train, including a few characters which were overstrikes of the symbols actually provided on that print train, for drawing lines around boxes on forms.
This keyboard, although some might find it cluttered, was at least made available as a commercial product by a large and reputable company. Thus, even if some might still find it intimidating, it really was kept within reasonable limits.
Speaking of keyboards only a few people had the opportunity to experience, and proceeding to our topic for this page of keyboards for large character sets, I commend to your attention this link, wherein are shown two keyboards designed by one Thomas Knight (the second one, however, according to one source, was actually designed by one John Kulp), and an illustration of a Japanese-language full-matrix keyboard as well.
An advertisement for the MIT CADR computer on Al Kossow's site shows a keyboard whose arrangement of keys is that of the keyboard termed the "Space Cadet" keyboard on the site mentioned in the previous paragraph; its layout is the following:
This was the original version of the keyboard used with the famous LISP Machine, commercially sold by Symbolics. Later versions of the keyboard removed the special characters from the keys, but retained more than the usual complement of special function keys, and also retained the three additional shifts, Meta, Super, and Hyper. This keyboard is illustrated below:
Although the symbols were not printed on the keys, a symbol shift was still present; the assortment of symbols was reduced somewhat, however, the provision of the complete Greek alphabet having been foreborne.
A keyboard of this type was made that would connect to the Macintosh computer, provided with a set of circuit boards that provided a Lisp Machine processor, this keyboard is known as the MacIvory keyboard, and is held in fond regard by many.
This type of keyboard was apparently in more general use at MIT's Artificial Intelligence laboratories; thus, the famous Emacs text editor was originally developed for use with this or a related keyboard, but it was originally a front-end for the TECO editor on a PDP-10 at that site.
Of course, there are those who will say that there is nothing particularly remarkable about an otherwise normal keyboard that provides an extensive set of special characters through the use of a special shift key:
and, more specifically, that one does not need to purchase an extra set of circuit boards for a Macintosh to give it this capability; the diagram above shows the characters obtainable on a Macintosh using the option key, alone or in combination with the shift key.
Some people find the Symbolics keyboard shown above to be the best keyboard for use with operating systems such as Linux; others find the keyboard below to be the one they prefer, and, thus, as another example of an ideal keyboard for this purpose, I show it here although it is not a particularly large keyboard:
this being the layout of the most recent version of the keyboard used with Sun workstations, which is available in two different styles according to taste.
Another example of a keyboard which included many special characters (including those found in APL, but without being primarily an APL keyboard) is the arrangement used at Lawrence Livermore Laboratories for an 8-bit version of ASCII.
The keyboard used for the Lawrence Livermore Labs version of 8-bit ASCII was based on the standard bit-pairing arrangement. This meant that a standard bit-pairing keyboard could be used, with only a very small amount of additional circuitry, and special keycaps.
The Ctrl, Ext, and Shift keys had a special design; by having plain flat tops, a single finger could hold down either both Ctrl and Ext, or both Ext and Shift, at the same time, thus facilitating the chording required to generate all the possible characters (including a second set of 32 control characters) with the keyboard.
It was claimed that this keyboard provided the whole APL character set, not including overstrikes, among the mathematical symbols and Greek letters it provided. However, this claim had at least one weakness: for encode and decode, it used characters which were clearly intended for drawing boxes for forms. So, if one wished to make the I-beam character as an overstrike, what one obtained looked more like a plus sign.
This keyboard dates from 1974. I thought it might have inspired the Knight keyboard and the later Space Cadet keyboard, as they are known, but I have since learned that the thread of their inspiration goes back to the early 1960s, through the keyboard used for the SAIL system at the Stanford Artificial Intelligence Laboratory. This system allowed a number of people to use terminals by using a disk drive at a central location to send the video signal to each of several terminals. Similar technology was also used in the IBM 1500 system, an educational computer system that could be built around either the IBM 1130 computer or the larger upwards-compatible (it supported two additional instructions) IBM 1800 computer. This meant that only one copy of much of the circuitry in a video terminal was needed to serve many users.
Several of the keyboards examined here attempted to provide, in addition to a large number of useful symbols, the entire APL character set. More recently, a keyboard design called the "union keyboard" provided the entire APL character set, including the overstrikes required by several APL dialects, through supplementary shifts to a keyboard which normally provides all the ASCII characters in their usual positions.
In the diagram above, some characters which occur in two possible locations are shown in either red or blue, the remaining characters accessed by the Alt key for APL use being shown in green.