[TUHS] DEC compilers (was Happy birthday, John Backus!)

Paul Winalski paul.winalski at gmail.com
Thu Dec 6 02:46:55 AEST 2018

Another curious compiler at DEC was VAX Ultrix Fortran.  DEC had
gotten a lot of push-back from the research community, who wanted to
use VAX and Ultrix but considered the f77 compiler inadequate and
wanted to use VAX Fortran, which only ran on VAX/VMS.  There was a
rush project to port VAX Fortran to Ultrix.  It was decided that the
quickest way to get a quality compiler to market was to have the VAX
Fortran compiler continue to emit VMS-format object files, and to
modify the VAX/VMS linker to accept a.out object files and to emit
a.out images.  Four of us worked on the linker port.  Two of us from
the VAX/VMS languages team did the linker mods and two engineers from
the Ultrix group wrote code to translate VMS debug information to Unix
stabs.  The resulting linker was called lk.  The VAX Fortran RTL was
also ported, and since we had a way to produce Unix executables from
VMS object files, it meant we didn't have to rewrite the RTL, which
was mainly in BLISS but also had modules in Fortran, VAX assembler,
and Pascal.

-Paul W.

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