Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!mips!news.cs.indiana.edu!rutgers!njin!uupsi!sugar!peter From: peter@sugar.hackercorp.com (Peter da Silva) Newsgroups: comp.sys.amiga.advocacy Subject: Re: 8-bit death (was Re: What the heck IS "Interactive TV"?) Message-ID: <1991Apr22.101854.3301@sugar.hackercorp.com> Date: 22 Apr 91 10:18:54 GMT References: <10944@mentor.cc.purdue.edu> <1991Apr21.195406.25574@sugar.hackercorp.com> <1991Apr22.021234.23673@neon.Stanford.EDU> Organization: Sugar Land Unix -- Houston, TX Lines: 20 In article <1991Apr22.021234.23673@neon.Stanford.EDU> torrie@cs.stanford.edu (Evan Torrie) writes: > The only address space limitation in the original Mac OS was a 24-bit limit > on pointers (and hence program addresses), since the upper 8 bits of a pointer > address were used for memory management. [This is now fixed in System 7.0, > following on from A/UX which fixed it 2-3 years ago]. Well, there was also the 128K available memory limit, which made the 32K code size limit (due to 68000 addressing modes) reasonable. Plus, didn't a whole bunch of stuff stop working when you went over 1M... and that's only 20 bits. Anyway, the amount of memory available for the O/S in the original Mac was pretty much the same as it was for 8-bit "operating systems" like CP/M. Thus you had a single-tasking, flat file system (when PRO Dos, on the Apple ///, already had directories), and so on. If they'd waited 1 year, they could have released it with 512K and gone to multitasking, but Jobs just had to get it out for 1984 for political reasons. -- Peter da Silva. `-_-' .