Infocom on PDP-11

[Tom Jennings]

On Wed, 11 May 2005, Paul Koning wrote:

> I only used BEATHE briefly; my recollection is that it used quotes to
> mark ALGOL keywords rather than reserved words, i.e.,
>     'i'f i=1 't'h'e'n ...
> instead of
> 	if i=1 then ...


Related, the Librascope/General Precision LGP-30 (and the LGP-21)
console/paper tape input system seems bizarre today.

The INPUT instruction reads tty characters and shifts them into
the accumulator until it receives an apostrophe character (yes,
'). The machine actually halts (well, infinite I/O wait) for each
character.

Computer response on each keystroke is therefore impossible. A
minimum of two keystrokes (or paper tape characters) is needed for
the CPU to see a "keystroke" -- KEY then '

LGP's ACT compiler (which they called fortran-like or algol-like,
depending on who you asked) source code looks awful:

s1'dim'a'500'm'500'q'500''
index'j'j+1'j-1''
daprt'e'n't'e'r' 'd'a't'a''cr''
rdxit's35''
s2iread'm'1''iread'q'1''iread'd''iread'n''
1';'j''
0'flo'd';'d.''
s3'sqrt'd.';'sqrd.''
1'unflo'sqrd.'i/'10';'sqrd''
2010'print'sqrd.''2000'iprt'sqrd''cr''cr''


(from http://world.std.com/~reinhold/comp-hist/actiiisample.html)



Modern character-based I/O paradigms were not universal and are
not the simplest. This kinda stuff was a major stumbling block for
program and language development.