The DOS 10 Commandments (fwd)

From: ajp166 <ajp166_at_bellatlantic.net>
Date: Thu Mar 15 20:24:13 2001

From: Sean 'Captain Napalm' Conner <spc_at_conman.org>
To: classiccmp_at_classiccmp.org <classiccmp_at_classiccmp.org>
Date: Thursday, March 15, 2001 7:54 PM
Subject: Re: The DOS 10 Commandments (fwd)


>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!

>> 4)
>> Thy application program and data shall all fit in 640K of RAM. After
all,
>> it's ten times what you had on a CP/M machine. Keep holy this 640K of
RAM,
>> and clutter it not with device drivers, memory managers, or other
things
>> that might make thy computer useful.
>
> Again, IBM is to fault for that one---the IBM PC reserved the memory
space
>above $A0000 for video and BIOS extentions. There have been
PCompatibles
>running MS-DOS that had more memory available, but only programs that
used
>MS-DOS exclusively would work on those machines.


Other non -PC hardware such as Rainbow went out to 896k and some of the
S100
based machines did the full meg using shadow rom.

>> 5)
>> Thou shall use the one true slash character to separate thy directory
path.
>> Thou shall learn and love this character, even though it appears on no
>> typewriter keyboard, and is unfamiliar. Standardization on where that
>> character is located on a computer keyboard is right out .
>
> While COMMAND.COM would only accept `\' as a path separator, MS-DOS
would
>internally use both `/' and `\' for path separators. There is an MS-DOS
>call to change the option character (from the default of `/') but I
don't
>remember what it was off the top of my head.


The other choise is the unix / or VMS [.....] form.

>
>> 10)
>> Learn well the Vulcan Nerve Pinch (ctrl-alt-del) for it shall be thy
saviour
>> on many an occasion. Believe in thy heart that everyone reboots their
OS to
>> solve problems that shouldn't occur in the first place.
>
> Isn't that more of a Windows thing than an MS-DOS thing?


It's really a hardware thing. Dos and most other OSs all see it and
have an option to do what they care to. The real point is that RESET
became the defacto solution for flakey code most of it outside DOS.

> -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.

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.

Allison
Received on Thu Mar 15 2001 - 20:24:13 GMT