pauls@hammer.UUCP (Paul Sweazey) (06/12/86)
> Of course, with DEC emphasizing Unibus disks (e.g., RA81s) plugged into > HSC50s and HSC70s, perhaps the I/O bandwidth issue is moot...I can't > believe that the transfer rates over the Unibus is any faster than > any of the more modern microprocessor busses. I mean, last time I looked > it was an open-collector, asynchronous bus (it did, after all, predate > tri-state logic!) I wouldn't dare to defend Unibus, but open-collector logic and asynchronous protocols are not inherently slower than synchronous buses or tri-state logic. In fact, by a significant margin, the two fastest industry standard 32-bit backplane buses are the Futurebus and the Fastbus. The keys to their speed are the use of properly terminated transmission lines and the elimination of clock skew. Either of these buses can transfer data at rates in excess of 100 Megabytes per second. -- Paul Sweazey {decvax,ucbvax,...}!tektronix!tekecs!pauls UUCP Tektronix, Inc. tekecs!pauls@tektronix CSNET P.O. Box 1000, M/S 61-215 tekecs!pauls.tektronix@Udel-Relay ARPANET Wilsonville, OR 97070 Work: 503-685-2563 Home: 503-692-5016