The CDC 6600 Architecture
The CDC6600 and its family members are part of the computer industry history.
A decade before the Cray 1, the members of the CDC6000 family
were not only expensive and the most powerful systems at the
time of introduction. They were also lean and wonderful architectures ! The elegance was also conveyed in
several publications (many by CDC), where all the necessary knowledge was explained from the ground up.
All you needed to know was supplied, clearly laid out, not just hints for efficient programming.
Basicly, you could rebuild your own computer by reading these books. 50 years later, they
are invaluable reminders and tools, we can see where the computer industry comes from and
realise that it is not that hard to do it ourselves, too. Thanks everybody for the great work !
These PDF files are mostly mirored from http://www.bitsavers.org/pdf/cdc/.
See also Scott's page at http://www.standardpascal.org/cdc6400.html. Thank you !
yg - 2012/01/13
Other links :
https://people.cs.clemson.edu/~mark/cdc6600.html (pretty pictures !)
From the last link :
"In 1970, J. E. Thornton wrote a book called Design of a Computer: The Control Data 6600,
which has been the standard reference on the CDC ever since. Long out of print, Mr. Thornton
gave Tom Uban permission to scan the book and make it available on the net."
I have mirored this amazing book here too. Here is a quote from Seymour Cray's foreword :
"[...] A book describing the characteristics of a modern large-scale digital
computer is a challenging undertaking. There is more detail information to
be presented than is possible in a single volume. An overview of the system
without being specific is generally too vague to convey the important characteristics
that are of real interest. The author in this book selects special
areas for detail treatment where those areas are unique to the machine
described. These are interconnected with a general description of the
system as a whole.
The reader can rest reassured that the material presented is accurate and
from the best authority as Mr. Thornton was personally responsible for
most of the detailed design of the Control Data model 6600 system."
Found thanks to Jonathan Jacky: I just discovered "the elephant book" (1963) !
"It was the first RISC -- the RISC philosophy was laid out chapter-and-verse by Thornton in the "Elephant Book" -- Jim Smith
(Local copy, mirored from
Other manuals for the CDC 6000 Series Computer
(not all are listed here, check this open directory)
6600 CENTRAL PROCESSOR Volume I : Control and Memory (march 1967)
(source of the picture above left)
6600 CENTRAL PROCESSOR Volume II : Functional Units
"This manual is intended to serve primarily as a reference text for the logic
analysis of the 6600 Central Processor Functional Units. [...]
The manual is divided into eight sections, each of which deals with one of
the eight 6600 Functional Unit types. [..]
Great emphasis has been placed on presenting the "concept" of a particular
logic circuit. Then, a "representative" analysis of the logic is made."
6000 Series overview
"This manual is intended to serve as an introductory text to 6000 computer systems
and to provide logical analysis of the peripheral processor units of this series.
As an introductory text, this manual discusses common design philosophies of the
CONTROL DATA 6400, 6500, and 6600 Computer systems."
Reference manual for 6400/6500/6600 computers, including instruction set.
A compilation of hardware information, instruction and I/O unit
codes for the PPU (12-bit barrel processor)
"Model dd 60A Computer Control Console"
Data Display's (CDC) Customer Engineering Manual
"This technical manual is for guiding personnel in the use and maintainance of
Data Display Model dd 60A. It consists of sever sections in one volume :
General Description, Operation, Theory of Operation, Maintainance, Maintainance Aids,
Parts Data, and Drawings."
"Assembly Language Programming for the Control Data 6000 and Cyber series" by Ralph Grishman
My favorite quote : "This book is dedicated to A6 & A7, without which none of the results
in this book could have been saved."
"This text is intended to familiarize users with the design of the
Control Data 6000 series, Cyber 70 series, and Cyber 170 series
computer systems and to enable them to write central processor
assembly language code.
This text will try to be explanatory and not simply expository.
That is, we won't simply tell you that the structure of the
computer is so and so, and the instructions are (1)..., (2)...,
etc., and "that's how things are." Undeniably, it is important
to know the instruction set backwards and forwards to write
really good code, but there is something else you should
understand: why the machine was built the way it was. Clearly
it is impossible to show that the 6600 is the best machine
configuration (it isn't, as IBM, Univac, and CDC's other
competitors will hasten to point out), but you should at least
see why it is a reasonably good design, and why some of the
choices were made as they were."
20160515: Elephant book