From: utzoo!decvax!ucbvax!info-vax
Newsgroups: fa.info-vax
Title: AST queueing from VMS device drivers
Article-I.D.: ucbvax.261
Posted: Tue Dec  7 20:06:47 1982
Received: Thu Dec  9 01:00:29 1982

>From lars@ACC  Tue Dec  7 18:30:44 1982
Mail-From: ARPANET host ACC rcvd at 7-Dec-82 0831-PST
To: info-vax@sri-csl
Remailed-Date:  7 Dec 1982 0928-PST
Remailed-From: the tty of Geoffrey S. Goodfellow  <Geoff5 at SRI-CSL>
Remailed-To: Info-VAX@SRI-CSL: ;

I am writing a VAX/VMS device driver, which occasionally needs to issue
ASTs to the owner of the device in order to announce unsolicited input.
By reading the I/O User's Manual, it would appear that
     a) the original VMS style of doing this would be to send a
	message from the driver to an associated mailbox
     b) a more recent style would be to allow a special i/o
	function code to mean "enable special asts to the following
	address".
I am going to peruse the TTDRIVER (class driver) microfiche to find
out what is involved in either. Does anyone have experience with either
technique and/or have helpful hints, examples or pointers ?

Lars Poulsen
Associated Computer Consultants

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