Path: utzoo!attcan!uunet!tektronix!orca!tekecs!frip!andrew
From: andrew@frip.gwd.tek.com (Andrew Klossner)
Newsgroups: comp.arch
Subject: Hardware-supported user handlers: examples
Message-ID: <10002@tekecs.TEK.COM>
Date: 17 May 88 19:32:15 GMT
References: <353@cf-cm.UUCP> <3095@edm.UUCP> <20618@think.UUCP> <1988May12.162207.16764@utzoo.uucp> <8722@ames.arc.nasa.gov>
Sender: andrew@tekecs.TEK.COM
Organization: Tektronix, Wilsonville, Oregon
Lines: 12

[]

	"Probably because practically every machine in existence routes
	*all* traps and interrupts to the kernel, which can pass them
	on to the user if it pleases.  I know of no machine, offhand,
	whose hardware has any notion of a "user handler"."

There's the PDP-10, with "Unimplemented User Operations" (UUOs) which
vector directly to the user's UUO trap handler.

  -=- Andrew Klossner   (decvax!tektronix!tekecs!andrew)       [UUCP]
                        (andrew%tekecs.tek.com@relay.cs.net)   [ARPA]