> On Mar 16, 2023, at 10:14 PM, Chuck Guzis via cctalk <cctalk@classiccmp.org>
> wrote:
>
> On 3/15/23 17:23, Jon Elson via cctalk wrote:
>
>> 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.
> ...
> The CDC 1604 (1959 (certainly had interrupts, both internal and
> external, but I do not believe it had memory protection. It did have a
> console loudspeaker driven by a 3-bit DAC, however.
I'm still trying to get a good answer to "when did the first commercial (as
opposed to one-off lab) computer appear that had interrupts as a standard
feature?"
It looks like there was the IBM 704, in 1958, with interrupts but some
documentation made me think it was an optional feature. The other machine from
1958 I can think of is the Electrologica X1. That is the machine that
confronted Dijkstra with the need to develop new theory to deal with the
non-sequential behavior of machines with interrupts, and his Ph.D. thesis was
the result. The X1 is also interesting in that it has what much later would be
called a BIOS -- a ROM-resident software library that included I/O services
including dealing with interrupts, an assembler/loader, and an operator
interface. Dijkstra wrote that, and the source code is in an appendix of his
thesis.
paul
