Windows 95 CD-ROM Msdosdrv.txt File (2 of 2)
ID: Q135485
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The information in this article applies to:
SUMMARY
This article contains a partial copy of the information in the
Msdosdrv.txt file from the Windows 95 CD-ROM. This article is the
second of two articles.
MORE INFORMATION
----------------------------------------------------------------------
Microsoft Windows 95 README for MS-DOS Device Drivers
August 1995
----------------------------------------------------------------------
(c) Copyright Microsoft Corporation, 1995
This document provides complementary or late-breaking information to
supplement the Microsoft Windows 95 documentation.
DBLBUFF.SYS -- Double Buffering
===============================
Loads the Dblbuff.sys device driver to perform double buffering.
Double buffering provides compatibility for certain hard-disk
controllers that cannot work with memory provided by EMM386 or Windows
running in 386 Enhanced mode.
If Windows Setup determined that your system may need double-
buffering, it will add a DoubleBuffer=1 entry to the [Options] section
of Msdos.sys, which will automatically load Dblbuff.sys. To manually
enable double-buffering, you can either add the above entry to
Msdos.sys, or add a DEVICE command in your CONFIG.SYS file.
Syntax
DEVICE=[drive:][path]DBLBUFF.SYS [/D+]
Parameters
[drive:][path]
Specifies the location of the Dblbuff.sys file.
/D+
Instructs Dblbuff.sys to double-buffer all disk I/O all the time.
By default, it will only double-buffer I/O to UMBs, and it will
automatically stop double-buffering if it appears to be
unnecessary.
DISPLAY.SYS
===========
Enables you to display international character sets on EGA, VGA, and
LCD monitors. This device driver must be loaded by a DEVICE or
DEVICEHIGH command in your CONFIG.SYS file.
Syntax
DEVICE=[drive:][path]DISPLAY.SYS CON[:]=(type[,[hwcp][,n]])
DEVICE=[drive:][path]DISPLAY.SYS CON[:]=(type[,[hwcp][,(n,m)]])
Parameters
[drive:][path]
Specifies the location of the DISPLAY.SYS file.
type
Specifies the display adapter in use. Valid values include EGA and
LCD. The EGA value supports both EGA and VGA display adapters. If
you omit the type parameter, DISPLAY.SYS checks the hardware to
determine which display adapter is in use. You can also specify CGA
and MONO as values for type, but they have no effect because
character-set switching is not enabled for these devices.
hwcp
Specifies the number of the character set that your hardware
supports. The following list shows the character sets that MS-DOS
supports and the country or language for each:
437 United States
850 Multilingual (Latin I)
852 Slavic (Latin II)
860 Portuguese
863 Canadian-French
865 Nordic
Additional character sets are supported by the EGA2.CPI and
EGA3.CPI files.
n
Specifies the number of character sets the hardware can support in
addition to the primary character set specified for the hwcp
parameter.
Valid values for n are in the range 0 through 6. This value depends
on your hardware. For EGA display adapters, the maximum value for n
is 6; for LCD display adapters, the maximum value for n is 1.
m
Specifies the number of subfonts the hardware supports for each
code page. The default value is 2 if type is EGA, and 1 if type is
LCD.
DRVSPACE.SYS, DBLSPACE.SYS
==========================
Determines the final memory location of DRVSPACE.BIN or DBLSPACE.BIN,
the part of MS-DOS that provides access to your compressed drives.
DxxSPACE.SYS loads the real-mode driver into upper memory blocks. This
can save 60K of conventional memory when you run Windows 95 in real
mode, and can save 100K or more if you use Microsoft Plus! for
Windows.
When you start your computer, Windows loads DRVSPACE.BIN or
DBLSPACE.BIN along with other operating-system functions, before
carrying out the commands in your CONFIG.SYS and AUTOEXEC.BAT files.
DxxSPACE.BIN initially loads in conventional memory because it loads
before device drivers that provide access to upper memory.
When you use DriveSpace or DoubleSpace to create a compressed drive on
your computer, the program adds a command for DxxSPACE.SYS to your
CONFIG.SYS file.
In the following syntax, for DxxSPACE type the filename for the
program you are using.
Syntax
DEVICE=[drive:][path]DxxSPACE.SYS /MOVE [/NOHMA] [/LOW]
DEVICEHIGH=[drive:][path]DxxSPACE.SYS /MOVE [/NOHMA] [/LOW]
Switches
/MOVE
Moves DxxSPACE.BIN to its final location in memory.
Initially, DxxSPACE.BIN loads at the top of conventional memory.
After Windows finishes carrying out the commands in the CONFIG.SYS
file, it moves DxxSPACE.BIN to the bottom of conventional memory.
When DxxSPACE.SYS is loaded by using the DEVICE command, it moves
DxxSPACE.BIN from the top of conventional memory to the bottom.
This can be useful for avoiding conflicts with programs that are
loaded from the CONFIG.SYS file and require access to the top of
conventional memory.
When DxxSPACE.SYS is loaded by using the DEVICEHIGH command,
DxxSPACE.BIN moves to upper memory, if available. Moving
DxxSPACE.BIN to upper memory makes more conventional memory
available.
/NOHMA
Prevents DxxSPACE.SYS from moving a portion of DxxSPACE.BIN to the
high memory area (HMA).
If MS-DOS is loaded into the HMA, DxxSPACE.SYS moves a portion of
DxxSPACE.BIN to the HMA (if there is enough room in the HMA). Use
this switch if you do not want DxxSPACE.BIN to use the HMA.
/LOW
Prevents DxxSPACE.SYS from loading at the top of conventional
memory. Use this switch if you have an MS-DOS-based program that
does not support DriveSpace or DoubleSpace at the top of
conventional memory. Note that use of this switch will prevent
Windows from reusing the memory occupied by DxxSPACE.sys.
Parameter
[drive:][path]
Specifies the location of the DxxSPACE.SYS file.
EGA.SYS
=======
Saves and restores the display when the MS-DOS Shell Task Swapper is
used with EGA monitors. If you have an EGA monitor, you must install
the EGA.SYS device driver before using Task Swapper. This device
driver must be loadedby a DEVICE or DEVICEHIGH command in your
CONFIG.SYS file.
Syntax
DEVICE=[drive:][path]EGA.SYS
Parameters
[drive:][path]
Specifies the location of the EGA.SYS file.
EMM386.EXE
==========
Provides access to the upper memory area and uses extended memory to
simulate expanded memory. This device driver must be loaded by a
DEVICE command in your CONFIG.SYS file and can be used only on
computers with an 80386 or higher processor.
EMM386 uses extended memory to simulate expanded memory for programs
that can use expanded memory. EMM386 also makes it possible to load
programs and device drivers into upper memory blocks (UMBs).
Syntax
DEVICE=[drive:][path]EMM386.EXE [ON|OFF|AUTO] [memory] [MIN=size]
[W=ON|W=OFF] [Mx|FRAME=address|/Pmmmm] [Pn=address] [X=mmmm-nnnn]
[I=mmmm-nnnn] [B=address] [L=minXMS] [A=altregs] [H=handles]
[D=nnn]
[RAM=mmmm-nnnn] [NOEMS] [NOVCPI] [HIGHSCAN] [VERBOSE] [WIN=mmmm-
nnnn]
[NOHI] [ROM=mmmm-nnnn] [NOMOVEXBDA] [ALTBOOT] [NOBACKFILL]
Parameters
[drive:][path]
Specifies the location of the EMM386.EXE file.
[ON|OFF|AUTO]
Activates the EMM386 device driver (if set to ON), or suspends the
EMM386 device driver (if set to OFF), or places the EMM386 device
driver in auto mode (if set to AUTO). Auto mode enables expanded-
memory support and upper memory block support only when a program
calls for it. The default value is ON. Use the EMM386 command to
change this value after EMM386 has started.
memory
Specifies the maximum amount of extended memory (in kilobytes) that
you want EMM386 to provide as expanded/Virtual Control Program
Interface (EMS/VCPI) memory. This amount is in addition to the
memory used for UMBs and EMM386 itself. Values for memory are in
the range 64 through the lesser of either 32768 or the amount of
extended memory available when EMM386 is loaded. The default value
is the amount of free extended memory. If you specify the NOEMS
switch, the default value is 0. EMM386
rounds the value down to the nearest multiple of 16.
Switches
MIN=size
Specifies the minimum amount of EMS/VCPI memory (in kilobytes) that
EMM386 will provide, if that amount of memory is available. EMM386
reserves this amount of extended memory for use as EMS/VCPI memory
when EMM386 is loaded by the DEVICE=EMM386.EXE command in your
CONFIG.SYS file. EMM386 may be able to provide additional EMS/VCPI
memory (up to the amount specified by the MEMORY parameter) if
sufficient XMS memory is available when a program requests EMS/VCPI
memory. Values are in the range 0 through the value specified by
the MEMORY parameter. The default value is 256. If you specify the
NOEMS switch, the default value is 0. If the value of MIN is
greater than the value of MEMORY, EMM386 uses the value specified
by MIN.
W=ON|W=OFF
Enables or disables support for the Weitek co-processor. The
default setting is W=OFF.
Mx
Specifies the address of the page frame. Valid values for x are in
the range 1 through 14. The following list shows each value and its
associated base address in hexadecimal format:
1 => C000h 8 => DC00h
2 => C400h 9 => E000h
3 => C800h 10 => 8000h
4 => CC00h 11 => 8400h
5 => D000h 12 => 8800h
6 => D400h 13 => 8C00h
7 => D800h 14 => 9000h
Values in the range 10 through 14 should be used only on computers
that have 512K of memory.
FRAME=address
Specifies the page-frame segment base directly. To specify a
specific segment-base address for the page frame, use the FRAME
switch, and specify the address you want. Valid values for address
are in the ranges 8000h through 9000h and C000h through E000h, in
increments of 400h. To provide expanded memory and disable the page
frame, you can specify FRAME=NONE; however, this may cause some
programs that require expanded memory to work improperly.
/Pmmmm
Specifies the address of the page frame. Valid values for mmmm are
in the ranges 8000h through 9000h and C000h through E000h, in
increments of 400h.
Pn=address
Specifies the segment address of a specific page, where n is the
number of the page you are specifying and address is the segment
address you want. Valid values for n are in the range 0 through
255. Valid values for address are in the ranges 8000h through 9C00h
and C000h through EC00h, in increments of 400h. The addresses for
pages 0 through 3 must be contiguous in order to maintain
compatibility with version 3.2 of the Lotus/Intel/Microsoft
Expanded Memory Specification (LIM EMS). If you use the Mx switch,
the FRAME switch, or the /Pmmmm switch, you cannot specify the
addresses for pages 0 through 3 for the /Pmmmm switch.
X=mmmm-nnnn
Prevents EMM386 from using a particular range of segment addresses
for an EMS page or for UMBs. Valid values for mmmm and nnnn are in
the range A000h through FFFFh and are rounded down to the nearest
4-kilobyte boundary. The X switch takes precedence over the I
switch if the two ranges overlap.
I=mmmm-nnnn
Specifies a range of segment addresses to be used (included) for an
EMS page or for UMBs. Valid values for mmmm and nnnn are in the
range A000h through FFFFh and are rounded down to the nearest 4-
kilobyte boundary. The X switch takes precedence over the I switch
if the two ranges overlap.
B=address
Specifies the lowest segment address available for EMS "banking"
(swapping of 16KB pages). Valid values are in the range 1000h
through 4000h. The default value is 4000h.
l=minXMS
Ensures that the specified amount (in kilobytes) of extended memory
will still be available after EMM386 is loaded. The default value
is 0.
A=altregs
Specifies how many fast alternate register sets (used for
multitasking) you want to allocate to EMM386. Valid values are in
the range 0 through 254. The default value is 7. Every alternate
register set adds about 200 bytes to the size in memory of EMM386.
H=handles
Specifies how many handles EMM386 can use. Valid values are in the
range 2 through 255. The default value is 64.
D=nnn
Specifies how many kilobytes of memory should be reserved for
buffered direct memory access (DMA). Discounting floppy disk DMA,
this value should reflect the largest DMA transfer that will occur
while EMM386 is active. Valid values for nnn are in the range 16
through 256. The default value is 32.
RAM=mmmm-nnnn
Specifies a range of segment addresses to be used for UMBs and also
enables EMS support. If you do not specify a range, EMM386 uses all
available adapter space to create UMBs and a page frame for EMS.
NOEMS
Provides access to the upper memory area but prevents access to
expanded memory.
NOVCPI
Disables support for VCPI programs. This switch must be used with
the NOEMS switch. If you specify the NOVCPI switch without
specifying the NOEMS switch, EMM386 does not disable VCPI support.
If you specify both switches, EMM386 disregards the MEMORY
parameter and the MIN switch. Disabling support for VCPI programs
reduces the amount of extended memory allocated.
HIGHSCAN
Specifies that EMM386 use an additional check to determine the
availablity of upper memory for use as UMBs or EMS windows. On some
computers, specifying this switch may have no effect or cause
EMM386 to identify upper memory areas as available when they are
not. As a result, your computer might stop responding.
VERBOSE
Directs EMM386 to display status and error messages while loading.
By default, EMM386 displays messages only if it encounters an error
condition. You can abbreviate VERBOSE as V. (To display status
messages without adding the VERBOSE switch, press and hold down the
ALT key while EMM386 starts and loads.)
WIN=mmmm-nnnn
Reserves a specified range of segment addresses for Windows instead
of for EMM386. Valid values for mmmm and nnnn are in the range
A000h through FFFFh and are rounded down to the nearest 4-kilobyte
boundary. The X switch takes precedence over the WIN switch if the
two ranges overlap. The WIN switch takes precedence over the RAM,
ROM, and I switches if their ranges overlap.
[NOHI]
Prevents EMM386 from loading into the upper memory area. Normally,
a portion of EMM386 is loaded into upper memory. Specifying this
switch decreases available conventional memory and increases the
upper memory area available for UMBs.
[ROM=mmmm-nnnn]
Specifies a range of segment addresses that EMM386 uses for shadow
RAM--random-access memory used for read-only memory (ROM). Valid
values for mmmm and nnnn are in the range A000h through FFFFh and
are rounded down to the nearest 4-kilobyte boundary. Specifying
this switch may speed up your system if it does not already have
shadow RAM.
[NOMOVEXBDA]
Prevents EMM386 from moving the extended BIOS data from
conventional memory to upper memory.
[ALTBOOT]
Specifies that EMM386 use an alternate handler to restart your
computer when you press CTRL+ALT+DEL. Use this switch only if your
computer stops responding or exhibits other unusual behavior when
EMM386 is loaded and you press CTRL+ALT+DEL.
[NOBACKFILL]
When EMM386 is configured to provide upper memory blocks (by using
the NOEMS or RAM switches), EMM386 will also automatically backfill
conventional memory if there is less than 640k, in order to bring
total conventional memory up to 640k. However, because Windows
does not support backfilled conventional memory, use the NOBACKFILL
switch if your computer has less than 640K of conventional memory.
HIMEM.SYS
=========
HIMEM is an extended-memory manager--a program that coordinates the
use of your computer's extended memory, including the high memory area
(HMA), so that no two programs or device drivers use the same memory
at the same time.
You install HIMEM by adding a DEVICE command for HIMEM.SYS to your
CONFIG.SYS file. The HIMEM.SYS command line must come before any
commands that start programs or device drivers that use extended
memory; for example, the HIMEM.SYS command line must come before the
EMM386.EXE command line.
Syntax
DEVICE=[drive:][path]HIMEM.SYS [/A20CONTROL:ON|OFF]
[/CPUCLOCK:ON|OFF][/EISA] [/HMAMIN=m] [/INT15=xxxx] [/MACHINE:xxxx]
[/NOABOVE16] [/NOEISA][/NUMHANDLES=n] [/SHADOWRAM:ON|OFF]
[/TESTMEM:ON|OFF] [/VERBOSE] [/X]
In most cases, you won't need to specify command-line options. The
default values for HIMEM.SYS are designed to work with most hardware.
Parameter
[drive:][path]
Specifies the location of the HIMEM.SYS file. HIMEM.SYS should
always be located on the same drive that contains your MS-DOS
files. If the HIMEM.SYS file is in the root directory of your
startup drive, you don't need to include a path. However, you must
always include the complete filename (HIMEM.SYS).
Switches
/A20CONTROL:ON|OFF
Specifies whether HIMEM is to take control of the A20 line even if
A20 was on when HIMEM was loaded. The A20 handler gives your
computer access to the HMA. If you specify /A20CONTROL:OFF, HIMEM
takes control of the A20 line only if A20 was off when HIMEM was
loaded. The default setting is /A20CONTROL:ON.
/CPUCLOCK:ON|OFF
Specifies whether HIMEM is to affect the clock speed of your
computer. If your computer's clock speed changes when you install
HIMEM, specifying /CPUCLOCK:ON may correct the problem; however,
enabling this option slows down HIMEM. The default setting is
/CPUCLOCK:OFF.
/EISA
Specifies that HIMEM should allocate all available extended memory.
This switch is necessary only on an EISA (Extended Industry
Standard Architecture) computer with more than 16 MB of memory; on
other computers, HIMEM automatically allocates all available
extended memory.
/HMAMIN=m
Specifies how many kilobytes of memory a program must require for
HIMEM to give that program use of the HMA. Only one program can
use the HMA at a time; HIMEM allocates the HMA to the first program
that meets the memory-use requirements set by this option. You can
specify a value from 0 to 63.
Set /HMAMIN to the amount of memory required by the program that
uses the most HMA memory.
The /HMAMIN option is not required; the default value is zero.
Omitting this option (or setting it to zero) specifies that HIMEM
allocate the HMA to the first program that requests it, regardless
of how much of the HMA the program is going to use.
The /HMAMIN option has no effect when Windows is running in 386
Enhanced mode.
/INT15=xxxx
Allocates the amount of extended memory (in kilobytes) to be
reserved for the Interrupt 15h interface. Some older programs use
the Interrupt 15h interface to allocate extended memory rather than
using the XMS (eXtended-Memory Specification) method provided by
HIMEM. If you use these programs, you can ensure enough memory is
available to them by setting xxxx to 64 KB larger than the amount
required by the program.
You can specify a value from 64 to 65535; however, you cannot
specify more memory than your system has available. If you specify
a value less than 64, the value becomes 0. The default value is 0.
/MACHINE:xxxx
Specifies what type of computer you are using. Usually, HIMEM can
detect your computer type successfully; however, there are a few
computers that HIMEM cannot detect. On such systems, HIMEM uses the
default system type (IBM AT or compatible). You might need to
include the /MACHINE option if your computer is a type that HIMEM
cannot detect and if HIMEM does not work properly on your system by
using the default system type.
Currently, systems that require this option include Acer 1100,
Wyse, and IBM 7552.
The value for xxxx can be any of the codes or their equivalent
numbers listed in the following table.
Code Number Computer type
----------------------------------------------------------------------
at 1 IBM AT or 100% compatible
ps2 2 IBM PS/2
ptlcascade 3 Phoenix Cascade BIOS
hpvectra 4 HP Vectra (A & A+)
att6300plus 5 AT&T 6300 Plus
acer1100 6 Acer 1100
toshiba 7 Toshiba 1600 & 1200XE
wyse 8 Wyse 12.5 Mhz 286
tulip 9 Tulip SX
zenith 10 Zenith ZBIOS
at1 11 IBM PC/AT (alternative delay)
at2 12 IBM PC/AT (alternative delay)
css 12 CSS Labs
at3 13 IBM PC/AT (alternative delay)
philips 13 Philips
fasthp 14 HP Vectra
ibm7552 15 IBM 7552 Industrial Computer
bullmicral 16 Bull Micral 60
dell 17 Dell XBIOS
/NOABOVE16
Specifies not to use INT 15h (ax==E801h) Compaq Bigmem support to
scan for extended memory.
/NOEISA
Specifies that HIMEM should not do EISA scanning for extended
memory.
/NUMHANDLES=n
Specifies the maximum number of extended-memory block (EMB) handles
that can be used simultaneously. You can specify a value from 1 to
128; the default value is 32. Each additional handle requires an
additional 6 bytes of memory.
The /NUMHANDLES option has no effect when Windows is running in 386
Enhanced mode.
/SHADOWRAM:ON|OFF
Specifies whether to disable shadow RAM (SHADOWRAM:OFF) or to leave
the ROM code running from RAM (SHADOWRAM:ON).
Some computers make ROM code run faster by "shadowing" it in RAM--
that is, by copying the ROM code into faster RAM memory at startup,
which uses some extended memory. On computers that use shadow RAM
and have less than 2 MB of RAM, HIMEM usually attempts to disable
shadow RAM to recover additional extended memory for Windows to
use. (HIMEM can disable shadow RAM only on certain types of
systems.) When HIMEM disables shadow RAM, the ROM code runs in the
slower ROM instead of RAM; therefore, your computer might run
slightly slower than it did before.
/TESTMEM:ON|OFF
Determines whether HIMEM performs a memory test when your computer
starts. By default, HIMEM tests the reliability of your computer's
extended memory each time your computer starts. This test can
identify memory that is no longer reliable; unreliable memory can
cause system instability or loss of data. HIMEM's memory test is
more thorough than the standard power-up memory test performed by
most computers. To prevent HIMEM from performing the memory test,
specify /TESTMEM:OFF. Disabling the memory test will shorten the
startup process. (The default setting is /TESTMEM:ON.)
/VERBOSE
Directs HIMEM to display status and error messages while loading.
By default, HIMEM does not display any messages unless it
encounters an error. You can abbreviate /VERBOSE as /V. (To display
status messages without adding the /VERBOSE switch, press and hold
the ALT key while HIMEM starts and loads.)
/X
Specifies not to use INT 15h (ax==E820h), the latest extended
memory support API.
RAMDRIVE.SYS
============
Uses part of your computer's random-access memory (RAM) to simulate a
hard disk drive. This device driver must be loaded by a DEVICE or
DEVICEHIGH command in your CONFIG.SYS file.
RAM drives are much faster than hard disk drives because your computer
can read information faster from memory than from a hard disk. A RAM
drive appears to be a normal hard disk drive; you can use it just as
you would any hard disk drive. The most important difference between a
real disk drive and a RAM drive is that because it exists only in
memory, information on a RAM drive is lost when you turn off or
restart your computer. You can set up as many RAM drives as you want,
up to the amount of memory your computer has. To do this, add one
RAMDRIVE.SYS line to your CONFIG.SYS file for each additional RAM
drive you want.
Syntax
DEVICE=[drive:][path]RAMDRIVE.SYS [DiskSize SectorSize [NumEntries]]]
[/E | /A]
Parameters
[drive:][path]
Specifies the location of the RAMDRIVE.SYS file.
DiskSize
Specifies how many kilobytes of memory you want to use for the RAM
drive. For example, to create a 640K RAM drive, specify 640. If you
don't specify an amount, RAMDrive will create a 64K RAM drive. You
can specify a value from 4 to 32767. However, you cannot specify
more memory than your system has available.
SectorSize
Specifies the disk sector size in bytes. The size can be 128, 256,
or 512 bytes. (If you include a SectorSize value, you must also
include a value for DiskSize.)
Generally, you should use the default sector size of 512 bytes.
NumEntries
Limits the number of files and directories you can create in the
RAM drive's root directory. The limit can be from 2 to 1024
entries; the limit you specify is rounded up to the nearest sector
size boundary. If you do not specify a limit, you can create up to
64 entries in the RAM drive's root directory. (If you include a
value for NumEntries, you must also include values for DiskSize and
SectorSize.)
If there is not enough memory to create the RAM drive as specified,
RAMDrive will try to create it with a limit of 16 directory
entries.
This may result in a RAM drive with a different limit from the one
you specified.
Switches
/E
Creates the RAM drive in extended memory.
For RAMDrive to use extended memory, your system must be configured
so that it provides extended memory, and a DEVICE command for the
extended-memory manager (such as HIMEM.SYS) must appear in your
CONFIG.SYS file before the DEVICE command for RAMDRIVE.SYS. In
general, it is best to create a RAM drive in extended memory if
your system has extended memory.
/A
Creates the RAM drive in expanded memory.
For RAMDrive to use expanded memory, your system must be configured
so that it provides expanded memory, and the DEVICE command for the
expanded-memory manager (such as EMM386, 386MAX, CEMM, or QEMM)
must appear in your CONFIG.SYS file before DEVICE command for
RAMDRIVE.SYS.
SETVER.EXE
==========
Loads the MS-DOS version table into memory. This device driver must be
loaded by a DEVICE or DEVICEHIGH command in your CONFIG.SYS file.
SETVER.EXE loads into memory the MS-DOS version table, which lists
names of programs and the number of the MS-DOS version with which each
program is designed to run.
Syntax
DEVICE=[drive:][path]SETVER.EXE
Parameters
[drive:][path]
Specifies the location of the SETVER.EXE file.
Keywords :
Version :
Platform :
Issue type :