Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!dali.cs.montana.edu!uakari.primate.wisc.edu!pikes!csn!kessner!david From: david@kessner.denver.co.us (David Kessner) Newsgroups: comp.sys.amiga.advocacy Subject: Re: 8-bit death Message-ID: <1991Apr28.203012.2793@kessner.denver.co.us> Date: 28 Apr 91 20:30:12 GMT References: <1991Apr26.085327.1@vf.jsc.nasa.gov> <1991Apr27.155155.12730@marlin.jcu.edu.au> <1991Apr28.122439.13393@sugar.hackercorp.com> Organization: Kessner, Inc. Lines: 49 In article <1991Apr28.122439.13393@sugar.hackercorp.com> peter@sugar.hackercorp.com (Peter da Silva) writes: >In article <1991Apr27.155155.12730@marlin.jcu.edu.au> cpmwc@marlin.jcu.edu.au (Matthew W Crowd) writes: >> This is wrong, MS-DOS is a 16bit operating system, 386's are the ones >> who don't benefit while running MS-DOS. > >Nope, MS-DOS is a straight copy of CP/M-80. Originally named QDOS (Quick and >Dirty Operating System) by its author's at Seattle Computer (they were well >aware that it was a kludge, only useful until they could afford to do it over >from scratch), it was just plain adopted by Microsoft after IBM asked them to >do an O/S for the IBM-PC. You see, IBM bought the PC from Seattle. > >In any case, MS-DOS is a bug for bug copy of CP/M. If that doesn't make it an >8-bit operating system for you, you're listening to too much propoganda. Now, I will be the _LAST_ person to extole the virtues of MS-DOS, but lets get our facts straight, will we? MS-DOS is a _16_ bit operating system. While it may be similar to CPM I doubt that it is a "staight copy" since CPM was strictly a 8 bit OS, and MS-DOS clearly has support for the _16_BIT_REGISTERS_ that the CPU has. Any BIOS/DOS reference book will provide you with enough _facts_ to show you that it does indeed use 16 bit numbers in the 16 bit CPU registers. That is _my_ definition of a 16 bit operating system-- the number of bits in the registers that it actually _uses_. Notice how this definition totally ignores any reference to the amount of RAM useable, disk space, multi-tasking, etc-- as it should do. The original PC used the 8088 CPU. This CPU is the same as the 8086-- both have 16 bit registers, but the 8088 has a 8 bit data bus where the 8086 has a 16 bit data bus. The software is the same for both. It's like the relationship between the 68000 and the 68008-- same CPU, different data bus size. Now, while MS-DOS is a 16 bit OS, it is _not_ a 32 bit OS. When running on a 386/486 MS-DOS does not utilize some of the features of the CPU-- like the MMU, 32 bit registers, or 'protected mode' (the full-blown mode that you would expect from a modern CPU). The long and short of it is, MS-DOS is _not_ an 8 bit OS running on a 16 bit CPU. It may _resemble_ an 8 bit OS, but it is not. It is 16 bits. Now, even though it is a 16 bit OS, it does not mean that Bill Gates didn't give it the "Look and Feel like CP/M". :) -- David Kessner - david@kessner.denver.co.us | do { 1135 Fairfax, Denver CO 80220 (303) 377-1801 (p.m.) | . . . If you cant flame MS-DOS, who can you flame? | } while( jones);