VAX9000 unearthed

[Jon Elson]

On 2/18/22 21:43, ben via cctalk wrote:
>
> The 70's was all low scale tech. I suspect it was the high 
> speed/edge rates more the power that kept ECL from common 
> use. Any other views on this topic. Ben, who only had 
> access to RADIO SHACK in the 70's.
> PS: Still grumbling about buying life time tubes at a big 
> price,
> just to see all tubes discontinued a year or two later.

Edge rates on pedestrian MECL 10K were not crazy fast.  Rise 
and fall of about 1 ns, but the gate propagation delay was 
ALSO about 1 ns, so that was a lot faster than TTL.  ECL was 
very easy to work with, crosstalk was not a common issue.  
But, you HAD to terminate any line over a foot, and better 
to make it 6" to be sure.  And, the termination and pulldown 
resistors ate a LOT of power!

Jon