Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!dali.cs.montana.edu!caen!hellgate.utah.edu!csn!kessner!david From: david@kessner.denver.co.us (David Kessner) Newsgroups: comp.sys.amiga.advocacy Subject: Re: 8-bit death Message-ID: <1991May7.090333.1449@kessner.denver.co.us> Date: 7 May 91 09:03:33 GMT References: <1991Apr30.112820.2451@sugar.hackercorp.com> <1991May1.064455.3058@kessner.denver.co.us> <2945.tnews@templar.actrix.gen.nz> Organization: Kessner, Inc. Lines: 44 In article <2945.tnews@templar.actrix.gen.nz> jbickers@templar.actrix.gen.nz (John Bickers) writes: >Quoted from <1991May1.064455.3058@kessner.denver.co.us> by david@kessner.denver.co.us (David Kessner): > >> the instruction set to it's registers indicate this. MS-DOS fully >> utilizes all of the 8088 features, so I will classify it as a 16 bit OS. > > When one calls an MS-DOS "interrupt" (haw, reminds me of the C= 64), > isn't the interrupt number a byte? > > That's a fundamental part of the OS that is only 8 bits. Huh? The 68000, 68030 (not sure of the 040), 386, etc all offer 256 different intterupts (READ: 8 bits). The C-64 (and the 6502/6510) had _THREE_, and that's if you include the RESET line! In any OS, there will be several areas that are only 8 bits, simply because it does not make sense to use more. For instance, keeping a count of the number of disk drives, serial ports, or printer ports would be pointless to use anything more than 8 bits-- when was the last time you has 255 serial ports on your 286/68000 based machine? The intterupts in MS-DOS are referenced with 8 bit numbers, because the 8088/8086 used 8 bit numbers-- the OS utilized the hardware. This has NEVER been a limitation. Even on a fully stocked machine, there are large amounts of these intterupts that are not being used simply because you can only put so much on a machine! Keep in mind that these intterupt numbers are only loosely the same as the 16 intterupt lines available on the ISA slot. The CPU allows for 256 intterupts. MS-DOS allows for 256 intterupts. The ISA bus only allows 16 of them through hardware (there are dozens of software intterupts, however). EISA, to the best of my knoledge, fixes this. In short: So? This is supposed to be a problem? >*** John Bickers, TAP, NZAmigaUG. jbickers@templar.actrix.gen.nz *** -- 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);