Looking back, 1965 was a milestone year for computing. It marked the formal first release of System 360 DOS (Disk Operating System). Fast forward 45 years, and today we celebrate the anniversary of DOS, currently known as System z z/VSE.
In observance of the 45th anniversary of z/VSE, we asked eight individuals who have a long history with z/VSE to relate an interesting event, happening, coincidence, or factoid that involves z/VSE. This request produced some interesting historical references, thought-provoking observations, and insightful views into the z/VSE community.
From the Early Years
Thurman O. Pylant, software architect at Sterling Commerce, Inc., recalled the ever-popular spooler in z/VSE, POWER:
"DOS (z/VSE) was only about two years old when I joined IBM as a systems engineer and most of my accounts were DOS users. Soon after, Larry Whitney wrote POWER [Priority Output Writers, Execution processors and Readers] in his garage and it was released as a Type 3 program.
"POWER was a SPOOLing program [Simultaneous Peripheral Operations On-Line] for DOS that allowed the overlap of actual printing with the running of programs that produced the printed data (a radical concept at that time). I thought this would be perfect for my grocery warehouse customer, who produced large amounts of printed output.
"We decided to do a benchmark with and without POWER. I had predicted a 25 percent improvement in work performed in the same time. We worked on setting up the benchmark, ran it, and then compiled the results. We only achieved a 24.70 percent improvement; the customer just said, ‘close enough.’
"This early experience with POWER made me want to do more with POWER: improving the RJE [Remote Job Entry] support, providing Source Library Inclusion [SLI] support, making it run virtual, working with [IBM] Development on VSE/POWER, putting VSE/POWER into its own address space, etc. It’s been a long-time love affair with software and with the VSE operating system itself.
"Improving efficiency and getting more out of existing hardware has always been an important focus for DOS, DOS/VS, DOS/VSE, VSE/SP, VSE/ESA, and now z/VSE. Happy birthday!"
Peter M. Horbach of B.O.S. Software GmbH remembers how early many of us started and the level of commitment seen in the z/VSE community: