[Simh] Regarding "Cutler THE father of VMS" myth

[Henk Gooijen]

-----Oorspronkelijk bericht----- 
From: Johnny Billquist
Sent: Sunday, March 08, 2015 9:48 PM
To: simh at trailing-edge.com
Subject: Re: [Simh] Regarding "Cutler THE father of VMS" myth

On 2015-03-08 21:39, Clem Cole wrote:
>
> On Sun, Mar 8, 2015 at 8:23 AM, Sergey Oboguev <oboguev at yahoo.com
> <mailto:oboguev at yahoo.com>> wrote:
>
>     If so, he may have a claim to inventing (a hint at) a microkernel
>     concept. ;-)
>
>
> ​Dykstra invented the ukernel -- its the THE kernel:
> https://en.wikipedia.org/wiki/THE_multiprogramming_system
>
> The paper itself is
> http://uosis.mif.vu.lt/~liutauras/books/Dijkstra%20-%20The%20structure%20of%20the%20THE%20multiprogramming%20system.pdf
>
> And all kernel hacker should read it some time.  It where the idea of
> semaphores are defined and the idea of "up" and "down" - (aka P/V).

Well, in all fairness, semaphores were used on railways already in the
19th century...

Johnny


That's true, but Dijkstra used it as a software technique, and that was new.
BTW, "up" and "down" is not the best translation for "P/V" operation.
P stands for the Dutch word "passeer" which roughly translates to "pass".
V stands for the Dutch word "verhoog" and that should be translated to
"increment". And that is exactly what happens: pass and increment (the
semaphore variable).

- Henk