[comp.os.msdos.misc] PC-DOS vs. MS-DOS

ESR@SLACVM.BITNET (Ed Russell) (10/18/90)

Recently there was a posting (since purged from our news disks) asking about
the differences between PC-DOS and MS-DOS when used on a clone.  (I believe
they were posted to this group but I'm not sure.)  The responses I saw all
ignored what I thought the original question was and centered either on the
differences between DOS 3.3 and DOS 4.01 or talked about the superficial
differences such as the different naming conventions for the hidden files
(IBMBIO/IBMDOS vs. IO/MSDOS).  I do not recall seeing anything that described
the real differences (if any) between the two.

All of the clones I use in various settings use PC-DOS 3.3.  I have not had
problems with DOS itself.  The only problem I have ever had is when invoking
some shareware programs that use (ugh) BASIC.  The PC-BASIC tried to do nice
things like resetting my CMOS settings, precipitating wierd error messages
and hanging the machine.  I bypassed that by using GWBASIC 3.1 which came with
MS-DOS 3.1 on my first AT clone.  So I am now using PC-DOS 3.3 with GWBASIC
3.1 and have not seen any (obvious) problems.

Along with whoever made the original request, I am also interested in the
actual differences between PC- and MS-DOS 3.3.  Are there things in PC-DOS
that may not work properly on clones or is simply a copyright/distribution
question?

hrbaan@praxis.cs.ruu.nl (Hayo Baan) (10/18/90)

In <90290.111217ESR@SLACVM.BITNET> ESR@SLACVM.BITNET (Ed Russell) writes:

> [deleted stuff]
>Along with whoever made the original request, I am also interested in the
>actual differences between PC- and MS-DOS 3.3.  Are there things in PC-DOS
>that may not work properly on clones or is simply a copyright/distribution
>question?

There is at least one difference in PC- and MS-DOS, and that is that PC-DOS
does not support changing the drive parameters with 'drivparm' (this is 
painfull if you try to install a 720kb drive in your IBM-XT as B:).

Another difference (only for 4.0?) is that PC (=IBM) dos insists on having the
OEM of yer harddisk set to IBM!

Greetings,
-- 


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browns@iccgcc.decnet.ab.com (Stan Brown, Oak Road Systems) (10/19/90)

In article <90290.111217ESR@SLACVM.BITNET>, ESR@SLACVM.BITNET (Ed Russell) writes:
> [Please explain the difference between PC-DOS and MS-DOS, not between
> different-numbered versions]

The principal difference between PC-DOS and MS-DOS is in their BASICs,
as you have discovered the hard way.  PC-DOS BASIC and BASICA are partly
on the PC-DOS diskette, partly in ROM BIOS (the machine hardware).  So
if you execute PC-DOS BASIC/BASICA on a non-IBM machine, it will try to
execute nonexistent instructions with, as we say, unpredictable results. 
It's perfectly safe to go the other way, i.e. to run GWBASIC on an IBM
machine, because GWBASIC has all of its instructions on the diskette.

More generally, PC-DOS is one version of MS-DOS.  Microsoft licenses
MS-DOS to computer manufacturers, who make whatever mods they want and
sell the result.  As far as I know, only IBM has actually given its
version a separate name, PC-DOS.  The other mfrs, such as Compaq, sell
"Compaq MS-DOS" and the like.  Many of these will work on each others'
machines, but there are no guarantees.  Part of the deal with Microsoft
licensing to the manufacturers is that each mfr is free to build things
into MS-DOS that will only work on that manufacturer's hardware.

As far as I know, BASIC/BASICA is the only part of PC-DOS that requires
IBM hardware.  Many manufacturers (including Dell, who made my machine),
say that their machines will run PC-DOS except for BASIC.

The above opinions are not attributable to any other person or company.
                                     email: browns@iccgcc.decnet.ab.com
Stan Brown, Oak Road Systems, Cleveland, Ohio, U.S.A.   +1 216 371 0043

phys169@canterbury.ac.nz (10/19/90)

In article <1502.271df2f5@iccgcc.decnet.ab.com>, browns@iccgcc.decnet.ab.com (Stan Brown, Oak Road Systems) writes:
> In article <90290.111217ESR@SLACVM.BITNET>, ESR@SLACVM.BITNET (Ed Russell) writes:
>> [Please explain the difference between PC-DOS and MS-DOS, not between
>> different-numbered versions]
> 
> The principal difference between PC-DOS and MS-DOS is in their BASICs,

Quite right. One bit of information to add is the reason - clone makers
couldn't put Microsoft's BASIC in ROM without infringing copyright - some how
the BASIC was better protected by copyright than the BIOS - I think the BASIC
keywords were the main thing.
> 
> More generally, PC-DOS is one version of MS-DOS.  Microsoft licenses
> MS-DOS to computer manufacturers, who make whatever mods they want and
> sell the result.  As far as I know, only IBM has actually given its
> version a separate name, PC-DOS. 

Trivial information dept: both Televideo and VCCP versions of DOS 2.1(1) have
separate names, (i.e. not MSDOS) and they share an oem number of 255. 

Mark Aitchison, Uni of Canterbury, New Zealand.