[TUHS] Harvard and Von Neumann Architectures and Unix
dave at horsfall.org
Sun Nov 26 09:15:23 AEST 2017
On Sat, 25 Nov 2017, William Cheswick wrote:
> On CDC machines, the return jump (RJ) instruction generally used to call
> subroutines deposited a jump instruction (EQ B0,B0,caller+1) in the
> called routine and jumped to the word after it. Clearly, languages like
> Pascal didn’t use that.
Ahhh; that brings back fond memories of my Cyber-72 days, and how easily
we CompSci kiddies broke into KRONOS...[*]
One of my favourite machines was the PDP-8; the JSR instruction planted
the return address in the first word and jumped to the second word, with a
return being done (IIRC) by an indirect jump to the first word.
Recursion? What's that?
Can't remember it now, but (on an LA-36 Duckwriter) it was something like:
(Could be abbreviated to "COMMO POO" and "REL POO" for those with a
sick sense of humour, which was most of us.)
and you got system privileges...
Dave Horsfall DTM (VK2KFU) "Those who don't understand security will suffer."
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