11 May
2005
11 May
'05
7:48 a.m.
Andy Holt wrote:
The PDP-7 with 8K of memory had a major impact on what B had for features.
Only with >8K of memory on the PDP-11 could you get a real compiler.
> Tom> The Whetsone Algol compiler ran, in one
pass, as fast as the
> Tom> source-input reader hardware, in 7000 words of memory! Though
> Tom> slow, it's a full-featured language, unlike C which is basically
> Tom> a portable assembler (I loved writing in C).
>
>
But remember too you really had only two sized variables, ints and
floating point.
I think the big problem with algol you never were ment to compile it,
just write
programns in it. 8K words are ample for a language that does not have
character
data. 32KB seems to be the smallest size a character orientated language
like C or Pascal.
Also most machines had built in floating point so the run time size was
small
I don't
know how big the first Algol 60 compiler (at MC Amsterdam) was
-- probably similar, quite possibly smaller.
Tom> Algol had it's share of horrors, but man it is the basis for
Tom> nearly all modern languages. C's block and scope structure came
Tom> directly from Algol.
Lobotomized, of course -- C left out a bunch of important parts from
the Algol block structure.
Some because C is really from the Fortran tradition (Dirty tricks are
sometimes useful and too strong typing and structure prevent such); some
because they had been discovered to be more problematic than helpful.
Algol 60 -> CPL -> BCPL -> B -> C (importing much from PL/I* ... which
was a union of concepts from Algol 60, Fortran IV, and COBOL using
Algol structure)
* this linkage is not normally recognised in histories of programming
languages, but when it is considered that the originators of C had been
involved in the Multics project ... an OS written in PL/I; the only
previous production OS that had been written in a HLL was that of the
Burroughs machines ... using a version of Algol (to complete the
circularity of these references).
Hm. Algol 60
certainly has no OO nature. Algol 68 does, the
beginnings of it.
Simula 67 was a derivative of Algol 60 that is normally recognised as the
foundation of OO.
Andy
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