The DOS 10 Commandments (fwd)

From: Sean 'Captain Napalm' Conner <spc_at_conman.org>
Date: Thu Mar 15 21:31:24 2001

It was thus said that the Great ajp166 once stated:
>
> >It was thus said that the Great Peter Joules once stated:
> >> 3)
> >> Thy hard disk shall never have more than 1024 sectors. You don't need
> that
> >> much space anyway.
> >
> > That's a BIOS limitation; talk to IBM about that one---they only
> allocated
> >10 bits for sector number in the INT 13h disk IO call.
>
>
> Wrong. 1024 was a hardware limitation of the early MFM controller cards
> and the bios honored it. FYI it was CYLINDERS not sectors. 1024 sectors
> would have only been 512k!

  Ah, that's what I get for not double checking the reference material. In
looking over it, it is indeed 10 bits for cylinder and six bits for sector
number.

> > -spc (Doesn't remember MS-DOS crashing quite so much ... )
>
> DOS being unprotected could crash, usually after the application
> wiped it from memory like CP/M! Any unprotected OS would be
> vunerable to being smashed by a runaway app.

  I know all about that---I used to write code under MS-DOS (And the Tandy
Color Computer and AmigaOS, all unprotected (memory wise) systems).
Assembly code, no less.

> Experience with DOS 3.11 and 5.0 is that for an unprotected OS
> it was fairly solid and not inclined to kill itself. I have two systems
> that live as DOS with uptimes measured in months.

  -spc (I never had any real problems with 2.11 either ... )
Received on Thu Mar 15 2001 - 21:31:24 GMT