History of the mainframe - from S/360 to Linux

This talk will dig into the long history of the IBM mainframe world. We will explain how it started, why it was successful at the time, how it evolved, why it has all these strange features, and what it looks like today. We will also give some insights into the operating systems and how they evolved with the architecture, and how mainframes eventually learned to run Linux.

Claudio Imbrenda
Nico Boehr

#gpn21 #SoftwareInfrastructure

[mahtin]

Prior to working VM’s, fork() did a full copy of data pages. If copy-on-write was going to fail on a cross page boundary, then s390 would have to revert to that method to run Unix.

The initial versions of the DEC VAX/750 (circa 1980) had a bug in its copy-on-write microcode that thwarted Unix ports in its day until the microcode was fixed. I sadly can’t find a reference; however, I was at the time the proud sysadmin of many VAXen’s and was well aware of this!

[computerproabc]

IBM promoted CICS(interactive) and IMS(database) on both IBM DOS and IBM os.
No these were not just batch Many software companies had clones
of cics or ims, very interactive systems,

[computerproabc]

NO BODY EVER ORDERED BPS, BOS, TOS SYSTEMS: They were ment to replace 1401 card and tape systems.
EVERY 360 I EVER SAW VISITED OR SERVICED(REPAIRED) HAD A CONSOLE TYPE WRITER AND DISK AND TAPE AND RAN IBM DOS OR IBM OS. (DOS WAS RUN ON 70% IBM COMPUTERS AND OS WAS RUN ON 30%(IBM LARGE COMPUTERS).

[computerproabc]

IBM NEEDED LINUX!!! THEY DID NOT HAVE AN INTERNET OPERATING SYSTEM!!!!
ADOPTING LINUX AND ABANDONING ITS OS WAS THE CHEAP WAY TO GO.

[computerproabc]

THESE GUYS ARE PRETTY NAIVE, THEY BELIEVE ANYTHING THEY HAVE READ!!!
A LOT OF THEIR COMMENTS ARE NONE SENSE.