Had some software conversion experience with the 360. When LSU went from the 7000 series machine to a 360, many programs had to be revised. Decided it was cheaper to buy time on a 7000 series machine than rewrite larger number crunching programs for the 360. Later, in the Oil Patch had a few encounters with the big 370. Even got permission to write and use an assembler routine. The 360 operating system made constructing overlays and JCL for big multi- step jobs a colossal pain.
Loved getting my very own VAX with VMS for the lab. It was amusing to watch someone at terminal when the big instrument burped out a scan of data -- everything else stopped until the data was decoded and stored. Line printer would stop dead, and the terminal would stop, too. Gave the data acquisition task high hard and software priority, since a real time data transfer must complete before the little controller computer on the instrument runs out of memory, or the data is gone forever. NASA had some concerns with satellite data acquisition which led to DEC fixing VMS to eliminate some cases where task switching wasn't fast enough. FORTRAN in the 7000 series scientific machines was a natural. With the 360, it was necessary to go back and make all the real variables double precision and adjust calling sequences accordingly. Also had some problems with length of integers. Seems to me the major failing in the standard for FORTRAN was not defining a minimum number of significant figures and magnitudes for single precision reals and requiring that single precision integers occupy the same size storage. When FORTRAN originated, the word oriented machines had a fixed length data word so the question probably never arose. In the old days we were operating with very little fast memory and slow disk reads and writes, so we squeezed as much as we could in memory and spent much time organizing the computation to minimize input and output. We also used the EQUIVALENCE statement to efficiently use and reuse the same memory at different steps. Recall exceeding memory by one cell in a tricky multiple overlay program. Used a machine between the 650 and the 7044, can't remember the number, that had variable word length. Was very slow at number crunching, but did enable me to balance rounding and truncation error for a subroutine that was widely distributed. It would examine ratios of input variables and determine how which numerical integration formula would be adequate for a two dimensional numerical integration. Then there was the little IBM machine we called the CADET -- can't add, doesn't even try. Used table lookup for arithmetic. Did pioneer the concept of a subroutine loading on call, as far as I know Choppy At 08:49 AM 9/24/03 -0400, "Buck" wrote: >Hmmmm, > >I wonder if Choppy has ever worked on an IBM 360? We had one at the >Shreveport Trade School on Hope Street back in the early 60's, LOL!
