Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!rutgers!ames!ucbcad!ucbvax!DK0RRZK0.BITNET!A0061 From: A0061@DK0RRZK0.BITNET Newsgroups: mod.computers.vax Subject: DRV11 on the uVAXII Message-ID: <8612051320.AA03052@ucbvax.Berkeley.EDU> Date: Fri, 5-Dec-86 09:08:02 EST Article-I.D.: ucbvax.8612051320.AA03052 Posted: Fri Dec 5 09:08:02 1986 Date-Received: Fri, 5-Dec-86 20:54:19 EST Sender: daemon@ucbvax.BERKELEY.EDU Organization: The ARPA Internet Lines: 12 Approved: info-vax@sri-kl.arpa Yesterday I worked on some data acquisition program for a uVAXII. It uses a DRV11 16 Bit paralel interface to poll for the status of some digital input lines. The same type of program on a PDP 11/73 or so works fine, but on the uVAX I often read some trash instead of the correct data word out of the DRV11 (using $CRMPSC with page frame number mapping). Note that no interrupts are involved, just normal device- register to memory operations. A work around was found by reading the register twice and if good compare taking the data as valid. How come ? Any ideas ? Claus Kalle, Regional Computing Center, Cologne University, West Germany