🚀 go-pugleaf

In article <BOB.89Aug15170146@tinman.cis.ohio-state.edu> Bob Sutterfield <bob@cis.ohio-state.edu> writes:
>In article <19115@unix.cis.pittsburgh.edu> msw@unix.cis.pittsburgh.edu (Matt S Wartell) writes:
>   ...emacs attempts to do everything...  This seems to be counter to
>   the Unix philosophy of ``a tool should do one job and do it well.''
>
>Perhaps you're looking at it wrong - each elisp package is a tool, and
>does its single job well.  Emacs is just the Lisp interpreter and user
>interface veneer that provides a common way to get to them all.

A sufficent explanation of the difference in system philosophy
between the UNIX operating system and the Emacs virtual operating
system is, I think, inherent in the difference in system history:

	UNIX grew up on a very small machine, the PDP-11

	EMACS grew up on a very large machine, the PDP-10

Admittedly, GNU Emacs is written in C and Lisp rather than in assembly
language and TECO as ITS/TWENEX Emacs is, but it still has the habits
and instincts of a program designed for a very large system.

The PDP-10 implements true virtual memory, with paging as well as
swapping, so the use of each page of physical memory is individually
scheduled for maximum throughput, and unused pages of a program's
image do not become resident in memory.  A running ITS/TWENEX Emacs
image typically uses only about 30 to 35 pages of physical memory -
more pages are mapped but not in core.  (A page is 512 36-bit words -
it will store 2560 7-bit bytes or 2048 9-bit bytes.)

The transitions from KI-paging (cf VAX/VMS pre-V4.0) to KL-paging (ca
1972, cf VAX/VMS circa V4.0), and from raw TECO to CTRL/R TECO (Emacs)
occurred roughly simultaneously, so Emacs unsurprisingly relies upon
free heavy-duty memory management.  ITS/TWENEX Emacs does not in fact
run on early PDP-10 processor models or under early PDP-10 operating
systems (PDP-6's or KA's, or TOPS-10), which lacked this (amoung other
things).  It is not enough for a machine to be simply "big".

Lum  (Your "system paleontologist")
-=-
-- 
Lum Johnson      lum@cis.ohio-state.edu      lum@osu-20.ircc.ohio-state.edu
"You got it kid -- the large print giveth and the small print taketh away."
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