In reference to Joe Feeley's "Computers: We, the Digital Immigrants," (March 2014) my first encounter was with a Burroughs B3500. I was an operator/end user and field engineer for Burroughs. Card readers/punches, paper-tape readers, 132-character line printers, magnetic tape drives and 42-in. sealed hard drives were all state-of-the-art back then. It was literally a room full.
Magnetic tape drive encoding techniques were rapidly evolving to try to cram more and more data into seven and then nine tracks. Some of those techniques are still used today on our disk drives.
CPU core memory (remember that?) was all of 48K words of 48 bits. Memory upgrades would take you up to a whopping 96K! That was when programming demanded efficiency and a most scrupulous use of carefully selected instructions.
Pretty well everyone had to be familiar with binary code, and some of the higher-level languages such as COBOL and FORTRAN. Internal logic was a mix of discrete silicon transistors and first generation TTL integrated circuits. Operator interface was a Model 35 teletype! CRTs were just starting to show up for that application in the early '70s.
However, the operating system was very advanced for its time. Some of the features still are retained today, such as multiprogramming (rapid sequential execution of instructions from different programs, so as to create the illusion that all programs are being executed simultaneously).
We could "simultaneously execute" 10 different programs at once. The operator challenge was to try to keep 10 jobs running for the most time on a shift. What competitive spirit! I will not bore you with the details of the various peripherals, but it can be said that each was a marvel of engineering for its day. Evolution was very rapid in order to keep ahead of the competition. So, some things just don't change.
Gerald Beaudoin,
automation manager,
Vergers Leahy
