RL02 version of UNIX6?

Jerry Weiss jsw at ieee.org
Fri Feb 3 00:00:05 CST 2017

> On Feb 2, 2017, at 10:06 PM, Noel Chiappa <jnc at mercury.lcs.mit.edu> wrote:
> ,,,,,,
> The advent of the /23 (with no CSW, and no KW11-L/P), made things more
> complicated. (The clock is pretty key - Unix needs one - several things,
> e.g. parts of the teletype drivers, require real-time delays provided by the
> clock. I've never tried to run Unix without a working clock, I'm not sure if
> it would run without slowly grinding to a halt as stuff waited for clocks
> delays that never happened.(

Of course many preemptive OS’es use clock or other interrupts to drive their task schedulers.

I recall a situation in which the LTC was buggy or someone just switched it off.
The OS didn’t crash, but its responsiveness was rather odd.  Disk and perhaps some 
terminal IO kept the scheduler going.   With many users we barely noticed a difference,
but when there were only 1 or 2 users, it just kind of crept slowly along.  Someone finally 
noticed the timestamps on files never changed.

jsw at ieee.org

More information about the cctech mailing list