Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!usc!apple!sun-barr!newstop!sun!stpeter.Eng.Sun.COM!cmcmanis From: cmcmanis@stpeter.Eng.Sun.COM (Chuck McManis) Newsgroups: comp.sys.amiga Subject: Re: details, details (some questions) Message-ID: <139571@sun.Eng.Sun.COM> Date: 25 Jul 90 20:19:13 GMT References: Sender: news@sun.Eng.Sun.COM Distribution: comp Organization: Sun Microsystems, Mt. View, Ca. Lines: 42 In article gow@sakari.mrceg (Ed Gow) writes: >1) How does the AmigaDOS scheduler work (specifically, what stops one >task to allow another to execute)? There is a clock interrupt like there is on most (all?) multitasking OSs that periodically interrupts the CPU and starts a new task if the current task's quantum has expired and there is another task ready to run. Other ways in which tasks change are system calls that can affect task state such as Signals being set can cause a task switch. From the perspective of a programmer this is all invisible, you just write your code the system will take care of the multitasking. The caveat is that you write your code assuming that there will be other tasks running and be nice about asking for things like more memory, devices, etc. >2) Is the Zorro bus a good bus? Is the spec openly available for >developing add-on hardware? It is as good a bus as your likely to find. It is a bit processor family specific (68K) but that isn't a necessarily a bad thing. >3) What books are best to learn more about this kind of stuff and to >understand the system calls? Well, there isn't a good technical introduction to the Amiga per se, however reading Volume 3 of the ROM Kernel Manual "Libraries and Devices" especially the part on the exec.library will give you a good feel for how the pieces work. Rob Peck's "Programmers Guide to the Amiga" has a pretty good overview of how those pieces work together. >I'm not easy to e-mail to because in things such as this GE is in the >dark ages. (They have, however, started working on frescos on the >ceilings so we're hoping for a renaissance.) Even brief postings of >this info would be much appreciated. And you can post to Usenet so things will never be the same again ... -- --Chuck McManis Sun Microsystems uucp: {anywhere}!sun!cmcmanis BIX: Internet: cmcmanis@Eng.Sun.COM These opinions are my own and no one elses, but you knew that didn't you. "I tell you this parrot is bleeding deceased!"