The 709x had data channels which ran asynchronously, and generated channel traps — i.e. interrupts. I don’t think it had a, say, 60Hz clock, but I/O interrupts would allow a certain basic level of multiprogramming. The IBM 1410 also had I/O interrupts, and even had a rudimentary optional teleprocessing supervisor. IBM turned some 1410s into a basic message switching system.
Sent from my iPad > On Mar 15, 2023, at 19:23, Jon Elson via cctalk <cctalk@classiccmp.org> wrote: > > On 3/15/23 18:32, Paul Koning via cctalk wrote: >> >> Apart from spooling, which uncouples slow I/O from execution, there is also >> "multiprogramming", which means being able to run more than one job >> concurrently. Timesharing does that, of course, but I think >> multiprogramming was intended to refer to batch systems that did so. >> > Yes, the IBM 709x ran in single-job fashion. I don't think it had > interrupts, so breaking off one program to schedule another was not possible. > Also, it had no memory protection. We had a 7094 at Washington University > in the late 1960s, and it was the main computer resource on campus. When the > moved up to a 360/50, they were able to benefit from multiprogramming, and > got a boost in throughput, although the 7094 was QUITE a bit faster than the > 360/50. > > Jon >
