[TUHS] What does `ld` stand for?

[Phillip Harbison via TUHS]

Christopher fujino via TUHS wrote:
> My friend, taking an OS course was wondering what `ld` stood for. After
> doing an online search, concluded "no one knows." Surely someone around
> here must remember why the linker is called `ld`? Thanks!

My computer career only goes back to 1978, but I usually heard the terms 
linker, loader, and linking loader more or less interchangeably. On UNIX 
v7 the ld command read a bunch of object (.o) files and created a binary 
you could run from the shell or exec(2) system call. Apparently the ld
command could also generate a combined .o file. but we never used that 
feature.

When we were reviving the digital half of the hybrid computer used to 
design the control systems for the Saturn V, the distinction was more 
pronounced. The digital half was an IBM 704 based on vacuum tubes and 
using magnetic drum for memory. You used an input station to build up a 
tape with the compiler, your program, the assembler, the linker, the 
libraries, and your data all on one tape in that sequence.

Next you took your tape to the input drive of the 704. The loader seemed 
to be implicit as in you pushed the "Load Tape" button and it loaded and 
ran whatever was on the tape. I guess you could say the human operator 
was the "loader". ;) Your program wrote to an output drive. You then 
took that tape to an output station which read the tape and printed the 
results.

You have to tip your hat to people who sent men to the moon using such 
primitive tools. After it was running we realized the Rockwell AIM-65 
evaluation boards we used to teach microprocessor classes had more power 
than this computer occupying a lab about 20' x 40'. UAH could not afford 
the space or power bill so it was disassembled. I wish it had been sent 
to the space museum to be an exhibit but sadly it was sold for salvage. 
It had tons of copper and a lot of gold. :(

-- 
Phil Harbison