Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!mips!spool.mu.edu!uwm.edu!uwvax!daffy!cat53.cs.wisc.edu!dinda From: dinda@cat53.cs.wisc.edu (Peter Dinda) Newsgroups: comp.sys.amiga.advocacy Subject: Re: 8-bit death Summary: I really don't want to continue this Message-ID: <1991May2.012127.28779@daffy.cs.wisc.edu> Date: 2 May 91 01:21:27 GMT References: <1991Apr28.122439.13393@sugar.hackercorp.com> <1991Apr28.162045.15585@daffy.cs.wisc.edu> <1991Apr30.112820.2451@sugar.hackercorp.com> Sender: dinda@garfield.cs.wisc.edu Organization: U of Wisconsin CS Dept Lines: 82 In article <1991Apr30.112820.2451@sugar.hackercorp.com> peter@sugar.hackercorp.com (Peter da Silva) writes: >In article <1991Apr28.162045.15585@daffy.cs.wisc.edu> dinda@cat55.cs.wisc.edu (Peter Dinda) writes: >> WRONG. > >I love it how these college freshmen are so bloody sure of themselves. > >Especially when they haven't been paying attention. As a young gentleman who is a hop, skip, and jump away from both a BSEE and BSCS, who has programmed privately for DOS and DOS/Windows and commercially (for IBM) for multithreaded OS/2, I take offense at your personal insult. Being a gentleman, I will not return it in kind. > >> MS DOS is a 16 bit REAL MODE operating system. You may be getting >> confused since something like OS/2 1.x is a 16 bit PROTECTED MODE OS, while >> OS/2 2.x is a 32 bit PROTECTED MODE OS. > >I'm not confused, bucko. You are. Look at what you wrote: full of intel >marketing terms for privileged mode, user mode, and so on. Umm, Intel, built the processors that OS/2 and DOS run on. I think they have the right to name what the modes are! Unlike something like a PDP-11 or VAX-11, 286 and 386 machines provide four levels of protection - not just a user and priveleged mode. > >> The simplest processor that >> can run MS DOS (the Intel 8088) is a 16 bit processor with an 8 bit data >> bus. > >As far as the programming model (the only one that counts) is concerned, >the 8088 is an 8-bit processor with 4 bank-select registers built in. There Sorry, the 8088 has a 16 bit ALU - most machines are characterized on the basis of two things - the ALU and the Data Bus Widths. The 8088 has an 8 bit Data Bus, but all internal processing is done 16 bits at a time. The register pairs can be used either as full 16 bit registers, or split in half to act as twice as many 8 bit registers. ES, DS, CS, and SS are used to point to current segments and a segment plus offset scheme is used - this is kind of like the Base plus offset addressing found in an IBM 370 - but I forget, that's also an 8 bit system in your POV. >were companies doing operating systems for bank-selected 8-bit micros that >would have blown your socks of: Cromix from Cromemco, a UNIX-like O/S on >multiple bank-switched Z80s. OS/9 from Microware, still available for the >Radio Shack color computer, and still a 16-bit O/S for all it's running >on a 6809. > >> MS DOS, or for that matter, QDOS, is not a direct copy of CP/M - even >> the command interpreters accept different commands. > >Oh, the shell defines the O/S? Look at the system calls in MS-DOS 1.x >some time. Bug-for-bug compatible with CP/M. Sorry, note by use of the word "even" - the system calls for CP/M were never implemented as software interupts, now were they? And CP/M didn't provide for Device Drivers did it? You didn't have to patch DOS 1.x to add new devices! > >> Finally, MS DOS has now >> been rewritten 4 times - pretty much elliminating any resemblence to CP/M, >> even in the file system, etc. > >Oh? It's not an extent-based file system, with 8+3 filenames, CR/LF as the >line terminator, and so on? It's not still purely single-tasking? They now >provide real interrupt-driven device drivers? > >From where I sit, the 2.0 system calls are nothing more than a frill. > >No. Actually, MS-DOS is worse than CP/M. CP/M never got caught into the trap >of becoming specific to one piece of hardware. Ah, yes. CP/M ran on something other than 8080 derivatives - good urban legend. DOS stays around because its what users demand and buy. If it were up to IBM and Microsoft, Intel based PCs would be using OS/2 right now. And with all your credentials you still have time to insult other readers of comp.sys.amiga.advocacy. My My, you must be good.