[TUHS] terminal - just for fun

[scj at yaccman.com]

Remember that writing programs on terminals was a relative latecomer --
FORTRAN was designed for punched cards.  Their 6-bit character set has
"numbers" and "letters" (no case need apply).  The printers and other
supporting peripherals printed capital letters, probably because you could
get legibility with fewer dots that way and didn't have to worry about
descenders.

At Bell Labs (before Unix days) programmers wrote their programs on coding
sheets and handed them in to a room full of keypunchers.  They would punch
the program up on cards, and then a second person would repeat the process
using a verifier, a piece of hardware that took in a punched card, and had
a keyboard, and would verify that what the person typed in was what had
been punched on the card.  Then the punched and verified deck of cards was
returned to the programmer, who could submit it to the mainframe to run
it.

Although the coding sheet had little tick marks to indicate the column
positions, the keypunchers took advantage of FORTRAN syntax to simply
ignore spaces (they did know enough to respect blanks in Hollerith strings
and to start typing the program in the appropriate column).  Leaving the
blanks out not only made the process go faster, but also reduced the
number of false failures in verification, where the original keypuncher
and verifier disagreed on how many spaces should be inserted.

The model 33 Teletypes that were the most common terminal attached to Unix
in the early days had only a single case, as I recall, being primarily
used with paper tape with a character set closely related to the character
set used on punched cards (although with some features that eventually
become supported in ASCII).  Unix, however, interpreted the "letters" in
the character set as lower case by default, which was highly unusual at
that time, since there were almost no printers or terminals that would
print upper and lower case.


> On Saturday,  2 August 2014 at  4:27:50 +0100, Tim Bradshaw wrote:
>>
>> On 2 Aug 2014, at 02:49, Dave Horsfall <dave at horsfall.org> wrote:
>
>> Did FORTRAN understand lowercase, always?
>
> No.  It was first implemented on the IBM 704, which had a 6 bit BCD
> character set.  No lower case.
>