Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site mit-eddie.UUCP Path: utzoo!watmath!clyde!burl!ulysses!gamma!epsilon!zeta!sabre!petrus!bellcore!decvax!linus!philabs!cmcl2!harvard!think!mit-eddie!RALPHW@C.CS.CMU.EDU From: RALPHW@C.CS.CMU.EDU Newsgroups: net.ham-radio.packet Subject: [Ralph.Hyre@IUS2.CS.CMU.EDU:] Message-ID: <926@mit-eddie.UUCP> Date: Fri, 10-Jan-86 18:01:54 EST Article-I.D.: mit-eddi.926 Posted: Fri Jan 10 18:01:54 1986 Date-Received: Mon, 13-Jan-86 08:09:35 EST Sender: bcn@mit-eddi.UUCP Organization: MIT, Cambridge, MA Lines: 34 From: Ralph W. Hyre Jr. I just noticed this on Usenet net.micro.68K, and thought those of you using 8530 SCC chips might be interested. TAPR might be interested as well, since they're building a 64180 based NNC. - Ralph (ralphw@cmu-cs-c.arpa) --------------- Posting-Version: version B 2.10.2 9/18/84; site ecsvax.UUCP Path: pt.cs.cmu.edu!rochester!seismo!lll-crg!qantel!intelca!amdcad!decwrl!decvax!mcnc!ecsvax!sfa From: sfa@ecsvax.UUCP (Sam Averitt) Newsgroups: net.micro.68k Subject: Re: VMEbus problems Message-ID: <1038@ecsvax.UUCP> Date: Wed, 8-Jan-86 07:43:59 EST References: <1201@gitpyr.UUCP> Organization: North Carolina Educational Computing Service This info comes from Howard Crawford at Telex Terminals in Raleigh NC. They have been having similar problems using the 8530 with a 64180. The problem apparently is in the interrupt ack versus vector read timing. The setup time required by the 8530 between int ack and read must be met. Otherwise the vector may come out meaningless. There must also be the right setup time between rec clock and chip clock. The exact values are in the databooks. It is also interesting to note that Apple says not to access the 8530 in the Mac more often than once every 2.2 usec. (from Inside Macintosh) so there must be a fair amount of settling inside the chip. Wayne Sung N C State University -------