🚀 go-pugleaf

David Boyes, re PDP-8 instruction set:
--But you could do such *cool* things with the microprogrammed
--stuff with group 1 and group 2 instructions! Remember clearing
--the accumulator *and* the link bit using a single instruction --
--7300, wasn't it? Or doing an OSR and a SZA to do neat things with
--the address register lights?
--
Yep, packing code was fun on the PDP-8 with its 128 word "pages".  You
could address page zero or the one you were in. Page zero was usually used
for indirect references to other pages.  I wrote a utility package including
DECTape transfers to the high field (only 4K could be seen by the DECTape
at first), as well as several other neat things, all in the last page
of low core.  The first address of the last page was 7600, which was
a variant of the "clear accumulator" command.  So I could use this instruction
in page zero as a referent to my package, as well as a -200 (128 decimal)
counter-initialization constant for the DECTape transfer package.

"Any program can be made one word shorter"
-- 
Martin Taylor (m...@zorac.dciem.dnd.ca ...!uunet!dciem!mmt) (416) 635-2048
If the universe transcends formal methods, it might be interesting.
     (Steven Ryan).