On Fri, 27 Jun 2003 00:27:13 +0000, rk wrote:

> For any program of significant size, I would want at a least a 
> rudimentary assembler so one can jump to symbolic addresses, have 
> reasonable names for constants, registers, etc.  Of course, this 
> wouldn't affect the size or runtime of the program.  I remember even in 
> the '70s and early '80s some rather slow FORTRAN compilers.  I don't 
> know about the speed of the assemblers back in the '60s.  I know there 
> were some programmers from back there in the group (added .history) and 
> perhaps they can chime in with their $0.02.

There was a time, which ended in the early 1970s when I was in college, in
which computer programming textbooks tended to be machine specific and
covered machine language, Fortran II, and assembly language in that order.

In the old days, computer programs tended to be carefully "desk checked"
before they ever saw the machine, computer time was more precious than
programmer time, so manually producing machine code was de rigeur.

I beleive that the machine which gave the impetus to using assembly
language rather than machine code was the IBM 605. This machine had
instructions which had a field which held the address of the next
instruction to be executed.  This is because it fetched instructions for
execution directly from a rotating drum memory. The trick was to arrange
the instructions so that the next instruction was under the read head when
it was needed. This lead to SOAP or the Share Optimizing Assembly Program.
The optimization was the allocation of the 'right' address to each
instruction.