X-Nico

2 unusual facts about OS/360 and successors


DOS/360 and successors

When developing a new hardware generation of unified System/360 (or S/360) computers, IBM had originally committed to delivering a single operating system, OS/360, also compatible with low-end machines; but hardware was already available and the OS/360 project fell further and further behind schedule, as described at length by Fred Brooks.

Inter-processor interrupt

The M65MP option of OS/360 used the Direct Control feature of the S/360 to generate an interrupt on another processor; on S/370 and its successors, including z/Architecture, the SIGNAL PROCESSOR instruction provides a more formalized interface.


History of IBM magnetic disk drives

The fixed head area could also utilized for TSO "swap" data (MVT) and system swap data (MVS) wherein the swap data consisted of a condensed set of pointers to the remaining system data, which was "demand paged", as required, not "swapped".

The Spooler

The Spooler was a systems software operating system package that provided spooling facilities for the IBM System/370 running DOS/VS, DOS/VSE environment, and IBM System/360 running DOS/360 or retrofitted with modified DOS/360, such as TCSC's EDOS.


see also