keeshu@nikhefk.UUCP (01/28/87)
[Replace this line with a beautiful thought]
Some days ago someone asked for the known patches to PC-DOS v 3.1.
Yesterday the following file was uploaded to my BBS (Opus_SAGA, +3120924442),
and I thought more people would appreciate the contents, so here it is :
Enjoy,
-- Kees
===========================<cut here>======================================
The CompuServe IBMPC SIG Users Group
------------------------------------
PATCHES FOR IBM DOS 3.1
-----------------------
************************************************************************
Note: In the patches which follow, it is assumed the user is familiar
with the use of DEBUG. The notation "xxxx" means "anything is ok".
The notation <cr> means press Enter.
************************************************************************
FIXED DISK CLUSTER SIZE
If you have a 10 Meg hard disk, the following information collated by
Bill Higgins, provides for 2K clusters instead of the standard 4K
clusters. Typically, you will free up about 10% of the disk space you
are currently using.
2K Cluster Size for 10MB Fixed Disks under DOS 3.1
Standard 10mb fixed disks formatted under DOS 3.1 utilize 4k clusters
(i.e., the minimum space allocated to any file is 4096 bytes), while
drives 20mb and larger utilize 2k clusters. I use a PC with twin 10mb
drives under DOS 3.1. Since I have a multitude of small files on these
disks, the smaller allocation unit's space saving advantage far outweighs
any theoretical disadvantage of additional overhead for DOS to handle the
added allocation units.
With the help of Bob Morse, SysOps Jim Gainsley, and Conrad Kageyama,
and the DOS Technical Reference, I was able to make the changes necessary
to use 2k clusters on both of my 10mb drives. By following the
step-by-step instructions below, you will be able to make the switch to
2k clusters yourself.
NOTE: THE FOLLOWING PROCEDURE WILL DESTROY ALL DATA ON THE FIXED DISK!!!
You will need the following:
(1) IBM PC-DOS version 3.1 (3.0 appears NOT to work).
(2) A disk utility such as DISK REPAIR (a part of the IBM PROFESSIONAL
DEBUG FACILITY), or DISMOD (a USS program, available on many BBS's),
or equivalent. Note: You will not need this, if you use the
Alternate Method in #4a below.
Most critical to the process is the sequence in which this procedure is
attempted. Here is the 4k to 2k cluster procedure:
(1) Do a complete backup of the fixed disk, using your current version
of DOS.
(2) Cold boot DOS 3.1, run FDISK to create or be sure that a DOS
partition exists on the Fixed Disk.
(3) Format the fixed disk using the DOS 3.1 FORMAT.COM program. Do NOT
use any parameters (no /s or /v).
(4) Using your disk utility, select the boot sector and view it.
See below for an explanation of the pertinent info in this sector.
At location AA below, you should see a value of 08 which is the
number of sectors per cluster. Change this to 04.
At location BB below, you should see a value of 0800 which is the
number of sectors per fat (in hex Word format). Change this to 1500.
The results should appear as in CC and DD below.
All changes to the fat sectors required for 2k clusters will be
accomplished by the subsequent format in instruction 6 below. No
other manual changes are required.
--------------------
Example of first few bytes in the Boot Sector of the fixed disk,
displayed in hex format, after formatting with DOS 3.1, and prior
to 2k cluster size changes: (The bytes of interest are located at
Boot sector Offsets 0Dh = Sectors per cluster, and 16h = Sectors
per FAT.)
EB299049 424D2020 332E3100 02080100 020002F3 50F80800
^^ ^^^^
AA BB
After the 2k cluster size changes:
EB299049 424D2020 332E3100 02040100 020002F3 50F81500
^^ ^^^^
CC DD
Where the data elements directly above AA are sectors per cluster,
and above BB are sectors per FAT.
(4a) Alternate Method:
If you would rather, and if you are familiar with the operation
of Debug, the following method can be used.
Under DOS 3.1, do:
DEBUG
-L 0 n 0 1 <cr>
-E 0D <cr>
xxxx:0D 08.04 <cr>
-E 16 <cr>
xxxx:16 08.15 <cr>
-W 0 n 0 1 <cr>
-Q
where, n = the fixed disk drive as follows:
If fixed disk is drive B then n=1
" C " n=2
" D " n=3
" E " n=4
NOTE: Be *really* careful when you do the L and W commands in
the foregoing sequence. Would be best to check your
work by doing DEBUG, then
-L 0 n 0 1 <cr> then doing
-D 0D L1 <cr> and
-D 16 L1 <cr> making sure that the results
are 04 & 15 respectively.
Then exit by doing
-Q
-------------------
A more detailed explanation of these two changes:
The number of sectors per cluster would change from 08 to 04, since
that's what this is all about. The sectors per FAT will change, in
order to accomodate (1) the increased number of possible FAT
entries, and (2) the increased size of each fat entry which will be
in 16-bit format instead of the former 12-bits. The value to use for
a 10 meg & 2k clusters would be 21 sectors, or 1500 in hex word
format. (In this case the 15 is all that counts. 15 hex = 21 decimal.)
(5) Exit the disk utility and do a cold boot with DOS 3.1. This is
critical, since the boot sector is read by DOS only once, at boot
time, in order to build the BIOS Parameter Block. Having different
info in the boot sector than what's in the memory-resident BPB will
give UNPREDICTABLE RESULTS.
The following is safest way to preceed. Please use it.
(6) Reformat the drive using the DOS 3.1 FORMAT.COM,
FORMAT C: /S
(You may also include /V, if you wish to include a volume label.)
DOS 3.1 FORMAT will NOT affect your changes to the boot
sector. (This a change from DOS 3.0 FORMAT, which re-writes
the boot sector.)
(7) Restore your files, BEING SURE TO USE the RESTORE parameter, /P
which prompts before restoring system files.
**** WARNING ****
YOU MUST NOT ALLOW THE TWO SYSTEM FILES, IBMBIO.COM AND IBMDOS.COM
TO BE RESTORED, EVEN IF THEY ARE DOS 3.1 !!! IF YOU DO, THEY WILL
NOT BE PUT IN THE PROPER LOCATIONS AND YOUR FIXED DISK WILL NOT BE
BOOTABLE AND YOU WILL HAVE TO REFORMAT !!!
Avoid restoring an earlier version of COMMAND.COM, but if you do
restore an earlier version, nothing is lost, just be sure to copy
a 3.1 version over it afterwards. You should now be operational
again, with 2k clusters.
Further info on the entries in the boot sector entries used to build
the BIOS Parameter Block can be found in the DOS 3.1 Technical
Reference, Page 2-28. Of course, I cannot warrant that this change
will work for all controller/disk combinations, particularly for
controllers and drives which are not 'XT clones' though it 'should
work' for all drives compatible enough to work under DOS 3.1.
Comments to: -- Bill Higgins [70575,307] CIS, IBMPC SIG --
**********************************************************
ENVIRONMENT SIZE
Thanks to Bob Morse, the environment size can be patched as follows:
DEBUG COMMAND.COM
-E 0D11<cr>
xxxx:0D11 0A.1E<cr>
-W<cr>
-Q<cr>
(1E is for a 544 byte nominal size. Use 3C for a 1K size.)
*********************************************************
SCREEN SCROLLING
From Ward Christensen, the ANSI.SYS scrolling patches to disable the
wait for retrace and the screen blanking have new addresses but they
work just fine. Using DEBUG, proceed as follows:
DEBUG ANSI.SYS
-E 02E3<cr>
xxxx:02E3 74.90 FB.90<cr>
-E 02EA<cr>
xxxx:02EA EE.90<cr>
-W<cr>
-Q<cr>
**********************************************************
DISABLE EDLIN AUTOMATIC .BAK FILE CREATION
On a BBS I found the patch from an unknown author to disable the
automatic .BAK file when using EDLIN. Using DEBUG proceed as follows:
DEBUG EDLIN.COM
-E 0CD5<cr>
xxxx:0CD5 56.41<cr>
-W<cr>
-Q<cr>
**********************************************************
AUTOMATIC INSTALLATION OF PRINTER FOR DOS PRINT
Also on a BBS I found the patch by an unidentified author to PRINT.COM
to obviate the need to type the desired printer port. If the printer
port is LPT1, then using DEBUG proceed as follows:
DEBUG PRINT.COM
-E 1788<cr>
xxxx:1788 E8.90 CB.90 02.90<cr>
-E 179A<cr>
xxxx:179A CD.90 21.90<cr>
-W<cr>
-Q<cr>
If the printer port is LPT2 then the following address must ALSO be
modified as follows:
-E 10CA 4 "LPT2"
*********************************************************
DISABLE AUTOMATIC HEADER IN FIND.EXE OUTPUT
The FIND program puts an automatic header ---------- filename in the
output listing. To disable this header, patch FIND.EXE as follows:
REN FIND.EXE FIND.TMP
DEBUG FIND.TMP
-E 0424<cr>
xxxx:0424 03.2C<cr>
-W<cr>
-Q<cr>
REN FIND.TMP FIND.EXE
**********************************************************
PERMIT MORE THEN 10 MISMATCHES IN COMP.COM
I have patched COMP.COM to permit 50 mismatches as follows:
DEBUG COMP.COM
-E 08E2<cr>
xxxx:08E2 0A.32<cr>
-E 0BF8<cr>
xxxx:0BF8 31.35<cr>
-W<cr>
-Q<cr>
**********************************************************
ECHO OFF
I have patched COMMAND.COM to set the default to echo off to
to obviate the need for the ECHO OFF and CLS statements at the beginning
of a batch file.
DEBUG COMMAND.COM
-E 1967<cr>
xxxx:1967 01.00<cr>
-W<cr>
-Q<cr>
Note 1: The default for AUTOEXEC.BAT files will still be ECHO OFF.
Note 2: If the last thing done in a .BAT file is to do ECHO ON, then
you will get two prompts at exit.
**********************************************************
FORMAT: Add BEEP at completion of formatting
Stephen Berg provided a patch to FORMAT.COM in DOS 2.1 to produce a
BEEP when FORMAT completes. The patch adapted to DOS 3.1 is shown
below. The patch is most easily made with a disk editor. Using a disk
editor look for the exact string:
Format another (Y/N)?
It begins at offset 142Fh (Note: This NOT a Debug address!) If you
are using DISMOD, the address is record 0014 byte 2Fh
Enter the following exact string (omit quotes), ^G means Ctrl-G:
"Do another (Y/N) ?^G " (Note that one blank space follows ^G)
If you wish to use Debug then:
DEBUG FORMAT.COM
-D 152F L20<cr> ;Displays "Format another..."
-E 152F "Do another (Y/N) ?",07," "<cr> ;Quotes must be included
-D 152F L20<cr> ;Displays your entry.
-w
-q
The 07h (^G) does the BEEP.
Below is what you should see after the first D command above.
DEBUG FORMAT.COM
-D 152F L20
xxxx:1520 46 F
xxxx:1530 6F 72 6D 61 74 20 61 6E-6F 74 68 65 72 20 28 59 ormat another (Y
xxxx:1540 2F 4E 29 3F 00 AF 0E 0D-0A 00 C7 0E 49 6E 76 /N)?........Inv
^^ ^
NOTE: THE 00H MUST NOT BE DISTURBED!!!
*********************************************************
COMMAND.COM -- SOME UNDOCUMENTED FEATURES
The following is from Bob Smith, author of 'Tall Screen'.
EXPANDING THE PCDOS ENVIRONMENT AREA:
A recent forage into DOS 3.1 COMMAND.COM uncovered the following
seemingly supported, but undocumented feature:
/E:NN Set size of Environment area to NN paragraphs. Range
is 10 to 62 Numbers outside that range are ignored.
The default is /E:10.
This feature is most useful when used in conjunction with the
SHELL= OPTION in CONFIG.SYS. In particular, my usage is as follows:
SHELL=C:\DOS\COMMAND.COM C:\DOS /P /E:20
Other options include:
/D Don't execute AUTOEXEC.BAT
/F Skip response to ABORT, RETRY, IGNORE question in the System
default INT 24h handler. (Quite likely this feature is
named /F for 'FLAKY'.)
A NOTE ON THE 'SHELL' COMMAND, ABOVE...
The sample 'SHELL=' CONFIG.SYS command, above, shows several
undocumented options available. In particular, the first parameter
shows where the initial copy of COMMAND.COM is to be found (in the
above example, on the '/DOS' subdirectory on the 'C:' disk). This is
as documented by IBM. The second parameter indicates the drive and
subdirectory from which COMMAND.COM is to be reloaded. Here again,
the '/DOS' subdirectory on 'C:'.
The '/P' parameter indicates that the substitution should be permanent.
Note that in the DOS 3.10 REFERENCE MANUAL, the above two parameters
are described for the 'COMMAND' command. What IBM doesn't tell you is
that they also work on the 'SHELL=' command in CONFIG.SYS
-----------------------
My thanks to Bob, Ward, and others for their patches.
Comments to: -- Ted Eyrick [72446,317] CIS, IBMPC SIG --
Edited by:
Jim Gainsley [76703,1007]
(SysOp) IBMPC SIG
CompuServe
8-9-85
9-2-85
==========================<end of DOS31.PAT>=========================
| UUCP : keeshu@nikhefk.uucp or : {[wherever]!seismo}!mcvax!nikhefk!keeshu
| FIDO : kees huyser at 28/9 or 500/11
| BITNET : u00212@hasara5.bitnet
| SNAIL : kees huyser, NIKHEF-K, PO Box 4395, 1009 AJ Amsterdam, Netherlandsjimb@tekigm2.UUCP (02/04/87)
In article <108@nikhefk.UUCP> keeshu@nikhefk.UUCP (Kees Huyser) writes: > COMMAND.COM -- SOME UNDOCUMENTED FEATURES > /E:NN Set size of Environment area to NN paragraphs. Range > is 10 to 62 Numbers outside that range are ignored. > The default is /E:10. I believe the number is really the number of bytes to set for the environment. I use the number 512 and it works fine. I believe the correct range is 160 - 32768. The default is 127 (that which you get without setting the size). > This feature is most useful when used in conjunction with the > SHELL= OPTION in CONFIG.SYS. In particular, my usage is as follows: > SHELL=C:\DOS\COMMAND.COM C:\DOS /P /E:20 > The '/P' parameter indicates that the substitution should be permanent. No. the '/P' tells command.com to execute your autoexec.bat file once command.com gets loaded. If you put the above shell statement in your config.sys file without the /P, your autoexec.bat file will not get executed. The reason is that you may not want to use command.com. Perhaps you wrote your own processor that you want to use in lieu of command.com. You would use the shell command to load it. You may not want to execute autoexec.bat. The /P gives you the option or ignoring it.
dick@zaphod.UUCP (02/04/87)
Has anyone run across the patches required under IBM's flavor of PC-DOS 3.1 to specify which disk drive MORE and SORT will use for their scratch files? -- Dick Flanagan, W6OLD ...!ucbvax!decwrl!sun!plx!dick (The usual disclaimers apply)
pinkas@mipos3.UUCP (02/05/87)
In article <1438@tekigm2.TEK.COM> jimb@tekigm2.UUCP (Jim Boland) writes: >In article <108@nikhefk.UUCP> keeshu@nikhefk.UUCP (Kees Huyser) writes: > > COMMAND.COM -- SOME UNDOCUMENTED FEATURES > > /E:NN Set size of Environment area to NN paragraphs. Range > > is 10 to 62 Numbers outside that range are ignored. > > The default is /E:10. >I believe the number is really the number of bytes to set for the >environment. I use the number 512 and it works fine. I believe the correct >range is 160 - 32768. The default is 127 (that which you get without >setting the size). > > > This feature is most useful when used in conjunction with the > > SHELL= OPTION in CONFIG.SYS. In particular, my usage is as follows: > > > SHELL=C:\DOS\COMMAND.COM C:\DOS /P /E:20 > >> The '/P' parameter indicates that the substitution should be permanent. >No. the '/P' tells command.com to execute your autoexec.bat file once >command.com gets loaded. If you put the above shell statement in your >config.sys file without the /P, your autoexec.bat file will not get executed. >The reason is that you may not want to use command.com. Perhaps you wrote >your own processor that you want to use in lieu of command.com. You would >use the shell command to load it. You may not want to execute autoexec.bat. >The /P gives you the option or ignoring it. No, no, no. First of all, you might both be correct. The environment size in versions of dos 3.1 and below was specified in paragraphs. Thut the correct range was 10 to 62. The default was 10. In version 3.2 Microsoft decided to be incompatible and to make people specify the size in bytes. So the valid range became 160 to ~32000. However, after tracking down the internals, it appears to me that specifying a size that is not a multiple of 16 results in wasted memory. i.e. the number is rounded up to the nearest multiple of 16, but the difference might be unreachable. So much for improvement. As far as the second item, Jim is correct. The /P parameter tells DOS to make the invoked COMMAND.COM remain resident permanently. Thus, it will enter the read/execute loop. See the documentation on config.sys' shell command and on the exec function. -Israel -- ---------------------------------------------------------------------- UUCP: {amdcad,decwrl,hplabs,oliveb,pur-ee,qantel}!intelca!mipos3!pinkas ARPA: pinkas%mipos3.intel.com@relay.cs.net CSNET: pinkas%mipos3.intel.com