PDP-8s and -10s

[Paul Koning]

>>>>> "Jochen" == Jochen Kunz <jkunz at unixag-kl.fh-kl.de> writes:

 Jochen> On Thu, 16 Jun 2005 05:53:53 +0100 "Andy Holt"
 Jochen> <andyh at andyh-rayleigh.freeserve.co.uk> wrote:

 Jochen> [CDC6600 in a FPGA]
 >> As the 6600 was entirely built with discrete components, not
 >> chips, and yet had to be physically relatively compact, I doubt if
 >> it had much more than say 20,000-25,000 gates. Nowadays that isn't
 >> anywhere near high end of the FPGA ranges.
 Jochen> I don't know how many gates, but the Book "Design of a
 Jochen> Computer CDC6600" states on page 20: "the entire 6600
 Jochen> Computer contains approximately 400,000 transistors". It used
 Jochen> "Direct-Coupled Transistor Logic" so there where way less
 Jochen> then 400,000 gates.  --

I missed that transistor count number.  But your conclusion is
incorrect; take a look at the DCTL schematics.  It shows one
transistor per gate input, so a 2 input NAND or NOR gate (which is
what an "FPGA gate" is) is 2 transistors.  That yields 200k gates, or
about double what I estimated in a different way.  A bunch of those
transistors are in the memory circuits, so we're not that far apart.

	  paul