14 Sep
2017
14 Sep
'17
11:33 a.m.
I only know what this means due to a stint on GCOS-3 and having my
boss/sysmgr explain that "threaded code" in the old sense could be smaller
than the equivalent CISC binary on the same machine:
https://en.m.wikipedia.org/wiki/Threaded_code
And no, it's not Threads :-)
- alec
On 14 Sep 2017 6:50 am, "Larry McVoy" <lm(a)mcvoy.com> wrote:
Doug, could you talk about this some more? Sort of
like Reddit's
explain it like I'm 5? Assume I'm dense but want to learn and tell
me how this worked again. Threaded? I'm guessing you mean that it
did paging, did that need threads in the current sense?
On Wed, Sep 13, 2017 at 11:48:44PM -0400, Doug McIlroy wrote:
--
---
Larry McVoy lm at mcvoy.com
http://www.mcvoy.com/lm
Check
out: ybc: a compiler for B <https://github.com/Leushenko/ybc>
From a historical standpoint, a plain B compiler
lacks a very important
attribute of B in Unix. Yes, B presaged some C syntax. But
its shining
property was that it produced threaded code, for which both compact
and expanded runtime support was available. The latter had software
paging. Thus B transcended the limited physical memory of the early
PDP-11s.
If you can't compile something, you can't run it. A prime example was B
itself. Without software paging it would not have been able to recompile
itself, and Unix would not have been self-supporting.
Doug