-----Original Message-----
From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Rich
Alderson
Sent: Wednesday, November 30, 2016 12:16 PM
To: 'General Discussion: On-Topic and Off-Topic Posts'
<cctalk@classiccmp.org>
Subject: RE: Thinking about acquiring PDP stuff
From: Brad H
Sent: Wednesday, November 30, 2016 9:16 AM
> That was kind of why I thought buying a PDP in pieces over time might
> be my way to go, even if it took eons to get everything I needed to
rebuild one.
> It'd be fun to try and piece one back together. But yeah, I'm trying
> to think of what I would do with it afterwards. :)
So what kind of system are you interested in? There is no such thing as a
generic "PDP". Before giving up the naming convention, DEC produced 7
different architectures all named "PDP-n" for small integers n (and designed
2 that were never built by DEC):
PDP-1: 18 bits, 6 instruction + 12 address (System Modules)
PDP-2: 24 bits (design only) (System Modules)
PDP-3: 36 bits (design only) (System Modules)
PDP-4: 18 bits, 5 instruction + 13 address (System Modules)
PDP-5: 12 bits (System Modules)
PDP-6: 36 bits, 9 instruction, 9 AC+index+indirect, 18 address (mainframe)
PDP-7: 18 bits (PDP-4 upwards compatible) (FlipChips)
PDP-8: 12 bits (PDP-5 upwards compatible) (FlipChips)
PDP-9: 18 bits (PDP-7 upwards compatible) (FlipChips)
PDP-10: 36 bits (PDP-6 upwards compatible) (mainframe)
PDP-11: 16 bits (FlipChips)
PDP-12: 12 bits (PDP-8 + LINC compatible) (FlipChips)
PDP-14: 12 bits (NOT compatible with the PDP-8 family) (FlipChips)
PDP-15: 18 bits (PDP-9 upwards compatible) (FlipChips)
PDP-16: register-transfer module machine, with 8-, 12- or 16-bit memory as
needed for particular application design.
Later members of each family were designated by suffixes (e.g. 8/i, 8/e, 8/A
and 11/40, 11/70, etc.) or newer names (DECsystem-10, DECSYSTEM-20). The
VAX was the first new architecture from DEC not to have a PDP-n designation
at all.
Rich
P. S. For most of us, I think, "DG" = Data General, not Digital Group.
Rich Alderson
Vintage Computing Sr. Systems Engineer
Living Computer Museum
2245 1st Avenue S
Seattle, WA 98134
>mailto:ri...@livingcomputermuseum.org
>http://www.LivingComputerMuseum.org/
Can I use 'dg'? :) I think Digital Group preferred to be uncapitalized if I
remember correctly.
Regarding PDP -- I'm just sort of dipping my toes in here. I'd like
something that looks similar to an 8/E -- front panel toggle switches,
preferably from before 1975. But it's all a function of price.. if I can
find a later 11 that isn't $600+, that might be a place to start. I'm open
to suggestions. I've always been curious about DEC -- the computer shop we
once frequented in Vancouver always had stacks of DEC stuff among its used
computer inventory. VAX stations mostly. But I never got around to buying
anything. Was too busy collecting classic Macs.
