[TUHS] What does `ld` stand for?

[Douglas McIlroy via TUHS]

Indeed, the 704 originally came without an OS. The Fortran compiler
was free-standing: punched cards in, punched cards out, stop on error
or completion. The operator read the stop location from the console
for the user to look up in a listing printed on 11x14 fanfold paper.

Like GE, MIT, and others, Bell Labs made its own OS and tamed the
Fortran compiler. Because Fortran used the whole machine, the OS was
swapped out (to the output tape!) during compilation. "Stop" locations
were automatically recorded in the job output.

Fortran came with source code. I stayed up with that one night
debugging a bizarre error: failure on computed gotos with 74 mod 75
branches. I wouldn't be surprised if our unlucky customer was the only
user ever to stumble on that one.

Doug

On Mon, Oct 26, 2026 at 8:06 PM Phillip Harbison via TUHS <tuhs at tuhs.org> wrote:
>
> John Levine wrote:
> > IBJOB had a loader but this sounds older than that.
>
> The IBM 704 had a button literally labeled "Load Tape". It loaded and
> ran whatever was on the input tap drive and wrote to the output drive. I
> don't think there was any hint of an operating system.
>
> --
> Phil Harbison
>
>