[comp.os.msdos.programmer] MS-DOS 4.01 summary

jdb@reef.cis.ufl.edu (Brian K. W. Hook) (01/31/91)

This file was written to me in e-mail from someone, I assume, at microsoft.
I found it very informative and interesting....I'm not sure if he wanted me
to post or not, so I have deleted his name.

| Many programs, including Norton Utilities, would just not work with
| DOS 4.00.  

True.  Some programs made use of undocumented (read : MS didn't
document because they knew they may need to be changed in the
future.  Only things which MS is willing or must cast into stone are
doc'd, because once it's doc'd (640K memory limit) it don't change)
things which happened to change in 4.0.  

Also, a few doc'd as changeable (in the official programming
publication of MS, the "Microsoft MS-DOS Programmer's Reference")
interrupts, 25 and 26, also changed in 4.0.  Int 25 & 26 are absolute
sector read & write.  The old int 25 & 26 interface was limited to
32Mb drives.  Supporting >32Mb drives required changing this
interface and the implementation of FCB calls (read : some cool
undoc'd stuff with FCBs don't work no more).

And there may have been a few bugs :)  

But when I called Norton, their tech support said Norton's 3.0 wasn't
working in 4.01 because Int 25, Int 26, and undoc'd stuff changed
between 3.3 and 4.01. 

| Also, DOS 4.00 consumed about 15K (not exactly sure) more
| of ye olde valuable memory under 640K.  

Varies from machine to machine, my ms-dos 4.01 is about 7K more than
my dos 3.30.  If you've got a >32Mb hard disk, SHARE gets loaded
automatically (it implements FCB calls on the large disks) and that's
some more.

| Anyway....DOS 4.00 was soon
| upgraded by Microsoft to DOS 4.01 in an attempt to kill the bugs. 
| This was only partially effective.

Kinda depends on whose DOS you got.  

BTW, IBM releases CSDs for PC-DOS.  Microsoft doesn't release CSDs.
Whether an IBM PC-DOS CSD will work on MS-DOS is a toss of the cards.

Also BTW, lots of hw manufacturers have introduced new partitions and
partitioning types which are MS- and PC-DOS incompatible, including 
Zenith, Wyse, Hewlett Packard, NEC, & AT&T . NEC, Wyse, and Zenith
allowed for >32Mb partitions in 3.2 and 3.3.  The others varied. What
that means is that if you've got Wyse DOS 3.2 or 3.3 and a 50-mb C:
drive, you may need to repartition when you upgrade...maybe not if
you upgrade to Wyse 4.01.  (Beginning to see why MS says to get DOS
and all upgrades from the hw manufacturer?)  

Common changes included partitioning, MODE, FORMAT, IO.SYS /
IBMBIO.COM, and adding PARK and installation utilities, subbing a
VDISK.SYS for RAMDRIVE.SYS, etc.  IBM had SELECT in 3.0.  My Compaq
came with an installation program for Compaq MS-DOS versions 3.31,
4.01 and Compaq OS/2 1.something, I forget.  

| DOS Shell:  Most people who have used the DOS 4.01 shell REALLY 
| disklike it and just get something like XTree or PCTools or Norton 
| Commander.  IT is highly unintuitive and difficult to use. Especially
| when you want to just type COPY C:\DOS\*.TXT \UTIL\DOC and have to
| use that annoying shell.

Actually, I've talked to people who *love* the shell.  I hate it.  It
sucks.  But I'm not really qualified to comment here, since I also
hate Xtree (pain in the ass) PCTools (bleah) and Windows FileMan
(throw up).  Haven't used Norton Commander.  This is because I'm a
command line person.  COPY C:\DOS\*.TXT \UTIL\DOC makes perfect
sense, and is a heck of a lot easier than having to learn ANY shell.

The shell does allow toggling the hidden attribute and renaming
subdirectories.  Which I also hate.  WHY SHOULD I HAVE TO RUN THE
SHELL TO DO THIS?????  REN and ATTRIB should have the SAME
FUNCTIONALITY.  (Too bad I'm not god, eh?)

| Installation:  The install program was not only difficult to use, it 

I agree totally, it's stupid.

| prevented "old-timers" from just easily booting a disk, doing a

PREVENTED????  HOW???? Boot off the INSTALL disk!  It says, "Insert
SELECT disk to continue installing MS-DOS OR PRESS ESC TO EXIT TO
DOS"!!  Press ESC, run FDISK, and either FORMAT C: /s or (if you've
got a compatible boot partition) SYS C:, etc etc.  It's a heck of a
lot easier (if you know what you're doing) than running that
installation program.

| Also, the install program puts things like FCBS and FASTOPEN which most
| people don't use.  As a matter of fact, FASTOPEN is downright
| dangerous when used with something like PC TOOLS compress or Norton
| Speed Disk, since the file pointers aren't updated when the files are
| moved.

FCBS won't hurt and is often needed, I hate (and would remove if I
were you) FASTOPEN and APPEND.  Both can kill you fast.  Hate TSRs.

Course, checking out and if nec modifying the config and autoexec are
numbers 1 and 2 on my list after installing ANY ANY ANY software.  And
as noted above, why use the install program anyway?

| Big Hard Drive Partitions:  Most people LIKED partitions at the
| times, since it was an easier way to keep track of information. 
| However, 32MB has become a severe limitation.  Most of us just used
| ONTRACK Disk Manager to get around the 32MB limit.  The problem with
| the DOS 4.01 was that you had severe incompatibilities with certain
| programs (i.e.  SpinRite, Optune, Norton Utils, Mace Utils, et. al.)
| that couldn't cope with the new FAT and partition structure. Luckily,
| most of the problems disappeared  as new versions of software were
| released.

Did these programs work with the big partitions of 3.31?  Compaq used
the same partition type and FAT structure as 4.01.  

| Memory Overhead:  The added memory of DOS 4.01 prevented many
| programs from even working, including Ventura Publisher and a couple
| of games.  This was not good, with the RAM cram we have to suffer
| through right now anyway.

true.

| To sum:  DOS 4.01 does, in fact, "suck beans".  I personal
| recommendation is to use COMPAQ DOS 3.31, which supports hard drive
| partitions greater than 32MB and is quite efficient.

On a Compaq, it's good.  Have you tried Compaq MS-DOS 4.01? (Their
modification of MS 4.01, as 3.31 is a modification of MS 3.30)


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