12 May
2005
12 May
'05
6:19 a.m.
>>>> "Tom" == Tom Jennings
<tomj at wps.com> writes:
Tom> 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 ...
Tom> Related, the Librascope/General Precision LGP-30 (and the
Tom> LGP-21) console/paper tape input system seems bizarre today.
Tom> The INPUT instruction reads tty characters and shifts them into
Tom> the accumulator until it receives an apostrophe character (yes,
Tom> '). The machine actually halts (well, infinite I/O wait) for
Tom> each character.
Ditto the IBM 1620, where all I/O instructions on all the devices
would stall the CPU while the I/O was in progress. In that case, the
input might terminate by one of several rules -- always a card for the
card reader, terminated by CR on the typewriter, or terminated by a
"record mark" (a distinct character) on the paper tape reader if I
remember right.
On the other hand, this approach did make I/O very easy -- a "card to
printer" program would take only three instructions and fit easily on
one machine language (decimal, not binary) card.
paul