[Info-vax] OS Ancestry

[Bob Eager]

On Thu, 13 May 2021 09:25:17 -0700, David Jones wrote:

> On Thursday, May 13, 2021 at 11:55:34 AM UTC-4, Bob Eager wrote:
>> On Thu, 13 May 2021 09:06:33 -0400, Bill Gunshannon wrote:
>> 
>> > Thank you. That takes me back a little bit further. But I fear the
>> > very origins, the driving model, may be long lost by this time. I
>> > have a number of very early textbooks on Operating Systems and none
>> > of them describe features common in VMS or RSX.
>> Which features were you thinking of, as a matter of interest?
> 
> When I took a micro-architecture class in college (~1983), the concept
> of an I/O interrupt completely baffled about half the students. The
> programming assignments on PCs running CP/M, though I had been using
> RSX-11M on an 11/44 for a couple years.

I/O interrupts were ther back in the 1960s, and possibly earlier. I 
started teaching OD theory and practice in 1978, and it was an absolute 
given.

We had an interesting assignment which required students (using a 68000 
board) to handle interrupts and time black-white transitions from a basic 
bar code reader, then work out a threshold and decode the value.




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