14 Sep
2017
14 Sep
'17
3:39 p.m.
From: Alec Muffett
"threaded code" in the old sense could be
smaller than the equivalent
CISC binary on the same machine
One can think of 'threaded code' as code for a new virtual machine, one
specialized to the task at hand.
For those who really want to delve in some depth, see the chapter "Turning
Cousins into Sisters" (Chapter 15, pg. 365) in "Computer Engineering: A DEC
View of Hardware Systems Design", by Bell, Mudge and McNamara.
Interesting factoid: The PDP-11 initially used a threaded FORTRAN
implementation. In line with the observation above (about a new virtual
machine), DEC actually looked into writing microcode for the -11/60 (which had
a writeable control store) to implement the FORTRAN virtual machine.
Noel