Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!think.com!mintaka!bloom-beacon!eru!kth.se!cyklop.nada.kth.se!news From: kire@cyklop.nada.kth.se (Jan-Erik M}ngs) Newsgroups: comp.sys.mac.programmer Subject: Re: Time Slicing? Message-ID: Date: 28 May 91 15:12:52 GMT References: <1991May27.150858.47099@vaxb.acs.unt.edu> Sender: news@nada.kth.se (Mr News) Organization: Royal Institute of Technology, Stockholm, Sweden Lines: 16 In-reply-to: kenc@vaxb.acs.unt.edu's message of 27 May 91 15:02:56 GMT In article <1991May27.150858.47099@vaxb.acs.unt.edu> kenc@vaxb.acs.unt.edu writes: I'm wondering if it's possible to make a system call from a VBL task? What I'm thinking of is trying out a little experiment (Yes, and probably crashing the machine), to hook a time slicer into the vbl list, and (sort of) providing preemptive multitasking.... Don't try "system calls" but you can hook a time slicer into the vbl-list and do your own multitasking, this is the way Minix on the Mac does its preemptive multitasking. But remember, there is no documentation on how the stack looks like from a VBL-interrupt, so I would not recommend it if you care about portability (don't even think about it on A/UX). But for fun, yes it's possible. Kire (kire@nada.kth.se)