VAX9000 unearthed

[Bill Gunshannon]

On 2/20/22 15:31, Chuck Guzis via cctalk wrote:
> On 2/20/22 10:10, Mark Kahrs via cctalk wrote:
>> I heard Butler Lampson once exclaim that ECL design was in some ways easier
>> than TTL.  If you terminated every line, you get controlled impedances with
>> controlled edges.  This was the design philosophy for the Dorado.
> 
> Indeed--ECL WW prototype boards usually had a 3rd row for SIP
> termination resistors alongside the DIP sockets.  One nice thing about
> ECL is that there are many fewer problems with power rail spikes.  On
> the other hand, the constant power consumption needs beefier power supplies.
> 
> I recall that Honeywell redid one of their mainframe designs in ECL,
> with somewhat disappointing performance results.  I don't recall the
> details offhand.

It's long enough ago that my mind is fuzzy, but I think Primes were
ECL.

bill