Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.3 alpha 4/15/85; site ucbvax.ARPA Path: utzoo!watmath!clyde!burl!ulysses!ucbvax!info-vax From: info-vax@ucbvax.ARPA Newsgroups: fa.info-vax Subject: Re: Linking Vaxes Message-ID: <8159@ucbvax.ARPA> Date: Fri, 14-Jun-85 12:27:33 EDT Article-I.D.: ucbvax.8159 Posted: Fri Jun 14 12:27:33 1985 Date-Received: Sat, 15-Jun-85 08:06:53 EDT Sender: daemon@ucbvax.ARPA Organization: University of California at Berkeley Lines: 34 From: Richard Garland 780 <--> microVAX-II Certainly DECnet is available and works. They had a zillion microVIXen at DECUS all DECnetted together. It is in my opinion the best way to connect VMS machines. As for connecting them, cheapest would be an asynch line. Just any port will do although I would tend towards a DMF32 on the 780 to avoid the character overhead. I don't know if DEC sells a Q-bus DMA asynch board, but third party vendors do. Otherwise just use the regular DZ-type thing on the micro VAX. In any case you will have the DDCMP (DECnet protocol) overhead on both machines. Next up the ladder would be a synch line - but once again I don't know of any Q-bus versions of these but there probably are some multi-drop things that runs on pdp-11's. Last and best is ethernet. The distance is too great for conventional connections but there was lots of talk at DECUS about repeaters and bridges. repeaters will stretch 1000 m (is that enough? only .6 miles) with an optical fiber. Bridges are not announced yet but I have heard rumors they will be shortly. They are similar to repeaters but work at the packet level (link- level) and in principal have no distance constraints since they are store-and-forward devices. (there was one working over a satelite last DECUS (Anaheim)). Both repeaters and bridges should be transparent to the software i.e. they will pass any protocol such as DECnet. Ethernet will give you the added bonus of being able to add terminal servers which could talk to either VAX without impacting the one not being logged into (i.e. no DECnet SET HOST overhead). Rg -------