Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!watmath!clyde!caip!elbereth!rutgers!sri-spam!nike!lll-crg!seismo!rochester!ritcv!cci632!rb From: rb@cci632.UUCP (Rex Ballard) Newsgroups: net.micro.atari16 Subject: Re: OS9 mudules to run in GEM Message-ID: <454@cci632.UUCP> Date: Fri, 3-Oct-86 11:16:51 EDT Article-I.D.: cci632.454 Posted: Fri Oct 3 11:16:51 1986 Date-Received: Sat, 4-Oct-86 12:37:33 EDT References: <8609300312.AA02344@ucbvax.Berkeley.EDU> <1138@batcomputer.TN.CORNELL.EDU> Reply-To: rb@ccird1.UUCP (Rex Ballard) Organization: CCI, Rochester Development, Rochester, NY Lines: 30 Summary: O.S. basics. In article <1138@batcomputer.TN.CORNELL.EDU> braner@batcomputer.UUCP (braner) writes: >[] > >I don't see why an ST implementation of OS9 couldn't include access >to the GEM graphics routines (VDI, and perhaps parts of AES). These >are in ROM anyway, might as well use them, or allow OS9 programs to >use them. (Portability? Ever tried running a graphics program on >an 'IBM-compatible' just to find out you've got the wrong graphics >card? 'Compatibility' is a myth!) >- Moshe Braner Actually, it's even easier than it looks. Both GEM and OS-9 use "vector tables" to access their "BIOS" routines. OS-9 could simply be an additional group of vector tables. OS-9 also has a nice capability in that it can use traps to access it's own, or somone elses routines. The basic ingredients of VDI are not that different, perhaps a few arguments would have to be moved from one place to another. As to 'IBM-compatible', anyone who has ever made a "plug compatible" accessory for IBM knows how risky a proposition this can be. I've worked for two different companies that stopped working for IBM when the risks didn't pay off. The main advantage of OS-9 is that object code compatibility can be obtained without even so much as re-compilation. Speed of execution might be a minor issue, but probably not significant with processors running nearly 1 mips, and actual bit-bumping being done by other chips.