DEC DOS was: PDP1 3625
Wonder who that was? I buttume it wasn't me. :-) At 54, I'm at least close to qualifying as an "old guy" (particularly acccording to...
TSO and more was: PDP1
I never really fully used TSO. I did use the SPF (and liked what it did), but... I used to think that way. I bought into the whole Harlan Mills software engineering etc...
Actually on the IBM 360-370 ... OSes , the Fortran system units were chosen-buttigned when the Fortran library was being generated, customized, installed for a given installation. Unit numbers were buttigned to the system units for: SYSIN, SYSOUT, SYSPRINT, SYSPUNCH, & SYSERR. The University of North Carolina at Chapel Hill originally had a UNIVAC (1 or 2) when the Research Computation Center was set up for the US Census bureau ~1960+ (and an alternate military command site). So when the TUCC computer center was set up with an IBM360-75 and UNC CH put in its 360-40, the people here not being steeped in IBM tradition chose to use 1 for SYSIN, 2 for SYSPUNCH, and 3 for SYSPRINT and also SYSERR. Soon they saw the need to get with the rest of the IBM world and solved the problem by producing a module UNIT567 which could be linked with programs that were written to expect those units for the system i-o units. Even in the mid 1980s and perhaps early 90s the locally written programs were being written using units 1,2,3. The reason that one needed UNIT567 was to get output and error messages and library messages to come out properly interleaved on the correct units, and-SYSIN DD *-SYSPRINT DD SYSOUT=A-SYSPUNCH DD SYSOUT=B etc. which were provided in catalogued procedures to work automatically. Not needing to provide-FT05F001 ... overrides. -- Rostyk