The Unix Heritage Society mailing list
 help / color / mirror / Atom feed
* [TUHS] Re: A second Unix Patent
@ 2023-03-04  1:57 Noel Chiappa
  2023-03-04  9:22 ` Ralph Corderoy
  2023-03-04 15:08 ` Clem Cole
  0 siblings, 2 replies; 7+ messages in thread
From: Noel Chiappa @ 2023-03-04  1:57 UTC (permalink / raw)
  To: tuhs

    > From: Douglas McIlroy

    > Typo, in v3 through v6 ...
    > 26^3 16-bit trigram counts didn't fit in the PDP-11 memory

Being mildly curious, I fed '26 3 ^p' into 'dc' to see just how big it was -
and got "17576", a 16-bit word array of which would fit into a PDP-11 64KB
address space.

I think the answer is in the first line - V3 didn't use the PDP-11 memory
management, so the kernel _and_ the application had to fit into 56KB. So
there may well have not been 36KB available to hold a 26^3 array of 16-bit
words.

The other possible explanation is that it was perfectly possible to run UNIXes
of that era (V4 on) on machines without enough main memory to hold the kernel
and a 'full-sized' process simultaneously. (Our original machine, an -11/40,
started out without a lot of memory; I don't recall exactly how much, though.
It had, I'm pretty sure, 3 banks of core; I was thinking it was 3 MM11-L core
units, which would be 3x16KB, or only 48KB, but my memory must be wrong;
that's not really enough.)

	Noel

^ permalink raw reply	[flat|nested] 7+ messages in thread
* [TUHS] A second Unix Patent
@ 2023-03-01 22:59 Warner Losh
  2023-03-02  4:41 ` [TUHS] " Douglas McIlroy
  0 siblings, 1 reply; 7+ messages in thread
From: Warner Losh @ 2023-03-01 22:59 UTC (permalink / raw)
  To: The Eunuchs Hysterical Society


[-- Attachment #1.1: Type: text/plain, Size: 303 bytes --]

In looking at the first AUUGN today, I noticed the following at the end of
a letter John Lions sent home when he spent a sabbatical at Bell Labs

[image: image.png]
I've seen the first patent, but not the second one... That's got to be a
joke or inside joke, right? Anybody know anything else about it?

[-- Attachment #1.2: Type: text/html, Size: 422 bytes --]

[-- Attachment #2: image.png --]
[-- Type: image/png, Size: 46129 bytes --]

^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2023-03-04 15:09 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-03-04  1:57 [TUHS] Re: A second Unix Patent Noel Chiappa
2023-03-04  9:22 ` Ralph Corderoy
2023-03-04 15:08 ` Clem Cole
  -- strict thread matches above, loose matches on Subject: below --
2023-03-01 22:59 [TUHS] " Warner Losh
2023-03-02  4:41 ` [TUHS] " Douglas McIlroy
2023-03-02  5:16   ` David Arnold
2023-03-03 13:29   ` Steve Mynott
2023-03-03 19:19     ` James Frew

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).