Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site peora.UUCP Path: utzoo!watmath!clyde!cbosgd!ihnp4!houxm!hjuxa!petsd!peora!jer From: jer@peora.UUCP (J. Eric Roskos) Newsgroups: net.micro,net.arch Subject: Re: Re: What if IBM used a 68000 Message-ID: <1880@peora.UUCP> Date: Mon, 30-Dec-85 08:31:00 EST Article-I.D.: peora.1880 Posted: Mon Dec 30 08:31:00 1985 Date-Received: Tue, 31-Dec-85 03:41:18 EST References: <212@fas.ri.cmu.edu> <702@petrus.UUCP> <6178@utzoo.UUCP> <147@intelca.UUCP> <133@ism780c.UUCP> Organization: CONCURRENT Computer SDC, Orlando, Fl. Lines: 28 Xref: watmath net.micro:13317 net.arch:2364 > > Also, for position > > independance during runtime, they limit some code pieces to 32K to allow > > branches with 16-bit signed pointers. And people ask why Mac is so slow! > > The Mac is slow because the resource manager is slow. The use of handles probably has very little to do with the slowness of the Mac; the user doesn't have to (usually) access things by handles very often, and the OS routines that do can cache up the handle in an address register. The Mac is perceived to be slow (by users) because someone (no longer with Apple) vehemently insisted on doing disk I/O via old-fashioned timing loops, like in the Apple II, rather than using a separate disk controller. This has other side-effects, too; e.g., losing mouse interrupts while disk I/O is going on. The Mac is so slow because the built-in floppy disk is so slow. If you use a RAM disk, or one of the better-designed hard disks, it's very fast. (I believe, if I'm not mistaken, that the disk I/O routine has to poll the serial ports while disk I/O is going on, also, in order to avoid losing serial interrupts.) [Count this as a comment that should have been in net.os.] "Some times software has to stand on its head to eliminate a chip in the hardware." -- A Mac software designer (I think Andy Hertzfield) -- UUCP: Ofc: jer@peora.UUCP Home: jer@jerpc.CCC.UUCP CCC DNS: peora, pesnta US Mail: MS 795; CONCURRENT Computer Corp. SDC; (A Perkin-Elmer Company) 2486 Sand Lake Road, Orlando, FL 32809-7642