13 Jul
2015
13 Jul
'15
5:52 p.m.
On 2015-07-13 21:16, Rich Alderson wrote:
From: Kip Koon
Sent: Sunday, July 12, 2015 10:52 PM
You could argue that the PDP-4 is the successor to the PDP-1. Unless I
remember wrong, it could run PDP-1 programs.
I would be most interested in finding out more
about this effort. Do you have
ongoing pictures documenting this effort? I'd love to have a PDP 8, 11, 12
someday, but I don't have the space for something like that much less the cost
involved so I'll have to be satisfied with emulators on my PC or eventually
building one or more of these systems with current technology like the SBC6120
if memory serves. Are there other possible alternatives? I used a PDP-8/E in
high school and college and have been quite interested in the high capability
PDPs like the PDP-11 Series for starters. I didn't know there were PDP 12
Series computers. Are there other PDP series computers as well?
Don't confuse higher numbers with higher capabilities, or even as being related
to each other. DEC created computers with 9 different architectures before the
32-bit VAX was even dreamed of.
The list of Programmed Data Processors goes like this:
PDP-1 18-bit word, 12-bit address
PDP-2 24-bit word, paper design only
PDP-3 36-bit word, paper design only
PDP-4 18-bit word, 13-bit address PDP-5 12-bit word
PDP-6 36-bit word, mainframe unrelated to PDP-3
PDP-7 18-bit word, PDP-4 successor
PDP-8 12-bit word, PDP-5 successor
12, 15 or 17 bit address. Depending on what hardware you have. Most
typical was/is 15-bit address space.
PDP-9 18-bit word, PDP-7 successor
PDP-10 36-bit word, PDP-6 successor mainframe
PDP-11 16-bit word, 16-bit address[2]
PDP-12 12-bit word, PDP-8/i + LINC hybrid
PDP-14 control processor for customer-built special purpose equipment
PDP-15 18-bit word, PDP-9 successor
PDP-16 Register-Transfer Module hard-wired processor, PDP-14 competitor[3]
There were later variants of some of these:
PDP-7A
PDP-8/s, PDP-8/i & /l, PDP-8/e & /f & /m, PDP-8/A
PDP-9/L
PDP-15/76
After 1971, they stopped naming things "PDP-n", with the exception of models
of
the PDP-11 (which eventually consisted of more than 20 models designated
PDP-11/nn), but even there the Pro-3x0 desktop systems were called something
else. Later models were microprocessor-based.
The later PDP-10 models were designated DECsystem-10 and DECSYSTEM-20.
The later PDP-8 models were the DECmate, DECmate II, and DECmate III (word
processing desktop systems) and the VT-78, all based on Intersil or Harris
microprocessors which were roughly the PDP-8/e in silicon.
"high capability PDPs" = PDP-10 & follow-ons. PDP-11? Pfeh.
As always, it depends on what people mean by "high capability". The
PDP-10 were undeniably physically larger, and had a much larger address
space. But they weren't exactly fast...
[1] 1 built by a customer, reputed to be an NSA front
company.
You forgot the actual anchor in the text. This relates to the PDP-3.
[2] With memory management, 18 or 22, in 16-bit
segments. Late models could
use separate instruction and data segments, for a total of 128KB in use at
one time.
??? What segments??? The PDP-11 have a plain simple page table. No
segments anywhere in sight. And each page is 8K.
You obviously need more exposure to PDP-11s, Rich. ;-)
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol