bit-paired keyboard
2 definitions found
bit-paired keyboard - Free On-line Dictionary of Computing (26 May 2007) :
bit-paired keyboard
<hardware> (Obsolete, or "bit-shift keyboard") A non-standard
keyboard layout that seems to have originated with the
Teletype ASR-33 and remained common for several years on
early computer equipment. The ASR-33 was a mechanical device
(see EOU), so the only way to generate the character codes
from keystrokes was by some physical linkage. The design of
the ASR-33 assigned each character key a basic pattern that
could be modified by flipping bits if the SHIFT or the CTRL
key was pressed. In order to avoid making the thing more of a
Rube Goldberg kluge than it already was, the design had to
group characters that shared the same basic bit pattern on one
key.
Looking at the ASCII chart, we find:
high low bits
bits 0000 0001 0010 0011 0100 0101 0110 0111 1000 1001
010 ! " # $ % & ' ( )
011 0 1 2 3 4 5 6 7 8 9
This is why the characters !"#$%&'() appear where they do on a
Teletype (thankfully, they didn't use shift-0 for space).
This was *not* the weirdest variant of the QWERTY layout
widely seen, by the way; that prize should probably go to one
of several (differing) arrangements on IBM's even clunkier
026 and 029 card punches.
When electronic terminals became popular, in the early
1970s, there was no agreement in the industry over how the
keyboards should be laid out. Some vendors opted to emulate
the Teletype keyboard, while others used the flexibility of
electronic circuitry to make their product look like an office
typewriter. These alternatives became known as "bit-paired"
and "typewriter-paired" keyboards. To a hacker, the
bit-paired keyboard seemed far more logical - and because most
hackers in those days had never learned to touch-type, there
was little pressure from the pioneering users to adapt
keyboards to the typewriter standard.
The doom of the bit-paired keyboard was the large-scale
introduction of the computer terminal into the normal office
environment, where out-and-out technophobes were expected to
use the equipment. The "typewriter-paired" standard became
universal, "bit-paired" hardware was quickly junked or
relegated to dusty corners, and both terms passed into disuse.
[Jargon File]
(1995-02-20)
bit-paired keyboard - Jargon File (4.4.4, 14 Aug 2003) :
bit-paired keyboard
n.,obs.
(alt.: bit-shift keyboard) A non-standard keyboard layout that seems
to have originated with the Teletype ASR-33 and remained common for
several years on early computer equipment. The ASR-33 was a
mechanical
device (see EOU), so the only way to generate the character codes
from keystrokes was by some physical linkage. The design of the
ASR-33
assigned each character key a basic pattern that could be modified by
flipping bits if the SHIFT or the CTRL key was pressed. In order to
avoid making the thing even more of a kluge than it already was, the
design had to group characters that shared the same basic bit pattern
on one key.
Looking at the ASCII chart, we find:
high low bits
bits 0000 0001 0010 0011 0100 0101 0110 0111 1000 1001
010 ! " # $ % & ' ( )
011 0 1 2 3 4 5 6 7 8 9
This is why the characters !"#$%&'() appear where they do on a
Teletype (thankfully, they didn't use shift-0 for space). The
Teletype
Model 33 was actually designed before ASCII existed, and was
originally intended to use a code that contained these two rows:
low bits
high 0000 0010 0100 0110 1000 1010 1100 1110
bits 0001 0011 0101 0111 1001 1011 1101 1111
10 ) ! bel # $ % wru & * ( " : ? _ , .
11 0 1 2 3 4 5 6 7 8 9 ' ; / - esc del
The result would have been something closer to a normal keyboard. But
as it happened, Teletype had to use a lot of persuasion just to keep
ASCII, and the Model 33 keyboard, from looking like this instead:
! " ? $ ' & - ( ) ; : * / , .
0 1 2 3 4 5 6 7 8 9 + ~ < > x |
Teletype's was not the weirdest variant of the QWERTY layout widely
seen, by the way; that prize should probably go to one of several
(differing) arrangements on IBM's even clunkier 026 and 029 card
punches.
When electronic terminals became popular, in the early 1970s, there
was no agreement in the industry over how the keyboards should be
laid
out. Some vendors opted to emulate the Teletype keyboard, while
others
used the flexibility of electronic circuitry to make their product
look like an office typewriter. Either choice was supported by the
ANSI computer keyboard standard, X4.14-1971, which referred to the
alternatives as "logical bit pairing" and "typewriter pairing". These
alternatives became known as bit-paired and typewriter-paired
keyboards. To a hacker, the bit-paired keyboard seemed far more
logical -- and because most hackers in those days had never learned
to
touch-type, there was little pressure from the pioneering users to
adapt keyboards to the typewriter standard.
The doom of the bit-paired keyboard was the large-scale introduction
of the computer terminal into the normal office environment, where
out-and-out technophobes were expected to use the equipment. The
typewriter-paired standard became universal, X4.14 was superseded by
X4.23-1982, bit-paired hardware was quickly junked or relegated to
dusty corners, and both terms passed into disuse.
However, in countries without a long history of touch typing, the
argument against the bit-paired keyboard layout was weak or
nonexistent. As a result, the standard Japanese keyboard, used on
PCs,
Unix boxen etc. still has all of the !"#$%&'() characters above the
numbers in the ASR-33 layout.
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