[TUHS] Origins of the SGS (System Generation Software) and COFF (Common Object File Format)
pnr at planet.nl
Fri Feb 24 07:37:50 AEST 2023
> Date: Thu, 23 Feb 2023 18:38:25 +0000
> Subject: [TUHS] Re: Origins of the SGS (System Generation Software)
> and COFF (Common Object File Format)
> For the sake of timelines:
> June 1980 - Publication date on the front page of the 3.0 manual in which the utilities are still very much research for PDP-11 and 32V-ish for VAX where distinctions matter.
> June 1981 - Publication date on the front page of the 4.1 manual in which the man-pages very much refer to all of this as the "3B-20 object format"
> June 1982 - Publication date on the front page of the 5.0 manual by which point these same pages had been edited and extended to describe the "common object file format"
> Additions at the 1981 release include dump(1), list(1), and the ld-prefixed library routines for managing these object files. These likewise persist in 5.0, SysV, and beyond as COFF-related tools.
> So this puts the backstop of what would become COFF at at least '81.
> - Matt G.
The surviving source code for SysV R2 supports this timeline:
- The header files (start from https://github.com/ryanwoodsmall/oldsysv/blob/master/sysvr2-vax/src/head/a.out.h) have dates of late ’82, early ’83.
- The source for exec() has a comment that refers to the 4xx magic formats as “pre 5.0 stuff”.
- The COFF format headers are #ifdef’ed for the 3B series.
Interestingly, the lowest magic numbers in the 5xx series are not for the 3B, but for the “Basic-16” and for the “x86”. That led me to this paper:
It seems that the roots of COFF go back to the initial portability effort for V7 and in particular the 8086 port (which was done in 1978 according to the paper).
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