11 Dec
2001
11 Dec
'01
3:49 p.m.
From: Dave McGuire
<mcguire(a)neurotica.com>
Date: Tue, 11 Dec 2001 21:13:30 -0500
To: classiccmp(a)classiccmp.org
Subject: Re: Prints for an 11/70
Reply-to: classiccmp(a)classiccmp.org
On December 11, Boatman on the River of Suck wrote:
Jeeeeezus Sridhar, how fast did you have in mind?
That rate, if Sridhar is looking at sub 5ns pin-pin, he's looking
at around 50 to 100MHz. Just my SWAG. FYI: PII 233 has 7ns
sync-sram cycling at 133MHz.
If true, that would be blisteringly fast PDP11/70 on size of a small
12" x 12" board roughly.
That means putting in certain lengths of critcial traces to get
timing come together at right moment (hence the zig-zag traces), low
voltage swings, 2 levels of caches, etc.
Blatent easy way out is emulate that 11/70 on athlon XP 1900+. :-)
Smack me if you dare. :-)
Cheers,
Wizard
Would
200MHz be fast enough ? A lot of the Xilinx fpga's offer 5ns pin to pin
In a word, no. 8-) -Dave