Design similarities with CDC mainframe?
This is a very interesting design, to me at least.· In many ways it resembles the design of the peripheral processing units of the Control Data 6600/6400 mainframes of the 60's and 70's that I worked on.· I believe that Seymor Cray designed those.· From what I remember, each "processor" (cog) had its own memory and registers, but shared the processor arithmetic logic during its time slot in the "barrel" (hub).· They each could access the I/O channels, but I believe that the software was written so that only one used any given channel.· One processor was dedicated to driving the keyboard and dual vector graphic displays.· They were also able to access the large main memory and communicate with each other and the central processing unit(s).· All of this was done by message passing (no interrupts).
All in all, a very cool machine with many·inovative design aspects and, for a time at least, the fastest computer on the planet.· There is an on-line copy of "Design of a Computer - The Control Data 6600"[size=-1] by J.E. Thornton (another Control Data engineer) at:[/size]
[size=-1][/size]
[size=-1]http://ed-thelen.org/comp-hist/DesignOfAComputer_CDC6600.pdf[/size]
[size=-1][/size]
[size=-1]The peripheral processing unit discussion starts on page 141.[/size]
Would anyone at Parallax like to comment on the similarities?
Oh, and I want one too.
All in all, a very cool machine with many·inovative design aspects and, for a time at least, the fastest computer on the planet.· There is an on-line copy of "Design of a Computer - The Control Data 6600"[size=-1] by J.E. Thornton (another Control Data engineer) at:[/size]
[size=-1][/size]
[size=-1]http://ed-thelen.org/comp-hist/DesignOfAComputer_CDC6600.pdf[/size]
[size=-1][/size]
[size=-1]The peripheral processing unit discussion starts on page 141.[/size]
Would anyone at Parallax like to comment on the similarities?
Oh, and I want one too.
Comments
So, a little difference I see.
-Martin
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Martin Hebel
Disclaimer: ANY Propeller statements made by me are subject to my inaccurate understanding of my limited time with it!
Southern Illinois University Carbondale -Electronic Systems Technologies
Personal Links with plenty of BASIC Stamp info
and SelmaWare Solutions - StampPlot - Graphical Data Acquisition and Control
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·1+1=10
You are 100% correct. The "commutator" method of processing pre-dates computers as we know them today. These same concepts were used in a mechanically timed fashion on the original EAM (electronic accounting machines) and hand wired (actaully plug wired) EAM machines that I originally learned on nearly 1/2 a centruy ago! Ah yes, the mighty IBM 85 collator, and 402 accounting machine - my favorites!
Essentially, even the venerable RPG compilers used a commutator (software timed processing) method of operation. Ever think of that?
Regards,
Bruce Bates
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Post Edited (Bruce Bates) : 2/23/2006 7:32:38 PM GMT
You're not quite correct on the I/O for the CDC PPUs. Instead, it is just like in the Propeller -- every PPU has access to every I/O channel.
The similarities are pretty neat. Memory capacity is fairly close (4k by 12 bits times 10 vs. 512 by 32 times 8 plus 8k more). I/O fairly similar (12 channels at 12 bits each vs. 32 bits). The Propeller is significantly faster, though (40 MHz vs. 1 to 4 MHz).
By the way, the closest analog is the CDC 6416, which was just the PPUs, no CPU.
Paul
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1+1=10