Re: Why do we still assemble?

> I think that the Burroughs people were pretty proud of the fact that their
> operating system had essentially no assembler code in it. I don't know
> for sure, but I think their (Algol) compiler generated object code
> directly.
> [Indeed it did. There was no assembler provided to customers, evidently
> they didn't miss it. -John]


Well, a bit of folklore, possibly hogwash, but...


At UC San Diego, A Burroughs for a long time was a primary mchine student
use. (later it became an admin computer, and a couple years ago it got
recycled electronics level :-) Some people wanted to build a LISP
interpreter for it. The architecture, if you're unfamiliar with it, is
stack based (with Algol the primary language), and to get pointers
necessary for LISP, a few behind the scenes tricks would have been
required (microcode?). Folklore has it that before anyone got very far,
an edict came down from Burroughs through the administration, that this
was not to be allowed, as a simple user error at the LISP level would have
crashed the entire machine. And so these people waited a few more years
until some other machines became available. Algol, Pascal, Fortran, and
the other languages available had no problem, since the compilers could
ensure that the stack wouldn't be mucked with and that program errors were
relatively harmless to the machine as a whole...


--
Darin Johnson
djohnson@ucsd.edu
[It is certainly true that the security of the Burroughs systems depended
on the correctness of application object code, and the compilers were
trusted components of the system. I hear that the easiest way to hack one
of them was to write yourself a tape in backup format containing an
executable program you made yourself that did things a compiler never
would let you do, then restore the program from the tape and run it. Oops.
-John]
--

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