21 Jun
2021
21 Jun
'21
10:46 a.m.
On Mon, 2021-06-21 at 08:26 -0700, Chuck Guzis via cctalk wrote:
Sigh. It's a shame that absolute (machine
language) coding isn't taught
anymore. The 1620 (and probably other IBM hardware) even had coding
forms for it--pencil-and-paper assembly coding. My recollection is
that the absolute forms were on the reverse side of the SPS coding form.
If you don't have another system to provide cross compilation/assembly,
you bootstrap from machine code.
IBM provided coding forms for the 1401, for both SPS and Autocoder.
They provided a "pocket reference card" for absolute machine code.
The machine had two one-character data registers that connected the CPU
to core, and two address registers. Three index registers were in core.
Univac provided a pocket reference card for the 1108, but didn't bother
with coding forms because assembler input was free form.