13 Jul
2015
13 Jul
'15
3:54 p.m.
From: Noel Chiappa
Sent: Monday, July 13, 2015 1:10 PM
> From: Rich Alderson
> PDP-12 12-bit word, PDP-8/i + LINC hybrid
Err, DEC sold a PDP-8/LINC hybrid themselves
(interesting machine, it's
covered in one of the standard PDP-8 processor manuals), before the PDP-12
came out; the -12 was basically a re-engineered version of the 8/LINC.
As noted by Christian Gauger-Gosgrove, I was only listing "PDP-n" systems.
The LINC-8 was not really a hybrid so much as a triumph of packaging. It
contained a complete PDP-8 ("Straight 8") CPU and a complete LINC CPU, the two
capable of accessing the same 12-bit memory. Changing from PDP-8 operation to
LINC operation was a matter of a physical switch.
The PDP-12 is different. It is essentially an enhanced PDP-8/i which can also
execute the LINC instruction set; each instruction set has an instruction to
change to the other mode of operation, so that a single program can contain
routines written in both. That is why I called it a hybrid.
Rich
Rich Alderson
Vintage Computing Sr. Systems Engineer
Living Computer Museum
2245 1st Avenue S
Seattle, WA 98134
mailto:RichA at LivingComputerMuseum.org
http://www.LivingComputerMuseum.org/