32-bit File Access
Encyclopedia
32-bit file access refers to the higher performance, protected mode
disk caching method introduced in Windows for Workgroups 3.11, which replaced SmartDrive
(Smartdrv). It bypassed MS-DOS
and directly accessed the disk, either via the BIOS
or (preferably) 32-bit disk access
(Windows-native protected mode disk drivers). This feature was a backport from the then-unreleased Windows 95
, as suggested by Microsoft's advertisements for Windows for Workgroups 3.11 ("the 32-bit file system from our Chicago project").
With the introduction of 32-bit file access and Long File Names in Windows 95, DOS was reduced to the role of a boot loader for Windows.
It was implemented using the VFAT, VCACHE, and IFSMgr
VxD
drivers.
Also, it should not be confused with 32-bit disk access
. Although both technologies are similar, 32-bit disk access (also known as FastDisk) pre-dates Windows for Workgroups 3.11. 32-bit file access provided a 32-bit code path for Windows to directly access the disk bus by intercepting the MS-DOS
Int 21H services while remaining in 386 protected mode
and at CPU speeds, rather than handling the Int 21H services in real mode by MS-DOS. 32-bit disk access offers relatively less performance and is less likely to work on many computers than 32-bit file access. 32-bit file access does not need 32-bit disk access.
Protected mode
In computing, protected mode, also called protected virtual address mode, is an operational mode of x86-compatible central processing units...
disk caching method introduced in Windows for Workgroups 3.11, which replaced SmartDrive
SmartDrive
SmartDrive was a disk caching program that shipped with MS-DOS versions 4.01 through 6.22 and Windows 3.x. It improved disk transfer rates by storing frequently accessed data in the main memory. Early versions of SmartDrive were loaded through a CONFIG.SYS device driver named SMARTDRV.SYS...
(Smartdrv). It bypassed MS-DOS
MS-DOS
MS-DOS is an operating system for x86-based personal computers. It was the most commonly used member of the DOS family of operating systems, and was the main operating system for IBM PC compatible personal computers during the 1980s to the mid 1990s, until it was gradually superseded by operating...
and directly accessed the disk, either via the BIOS
BIOS
In IBM PC compatible computers, the basic input/output system , also known as the System BIOS or ROM BIOS , is a de facto standard defining a firmware interface....
or (preferably) 32-bit disk access
32-bit Disk Access
32-bit Disk Access refers to a special disk access and caching mode available in older, MS-DOS-based Microsoft Windows operating systems. It was a set of protected mode device drivers that worked together to enhance the system's BIOS...
(Windows-native protected mode disk drivers). This feature was a backport from the then-unreleased Windows 95
Windows 95
Windows 95 is a consumer-oriented graphical user interface-based operating system. It was released on August 24, 1995 by Microsoft, and was a significant progression from the company's previous Windows products...
, as suggested by Microsoft's advertisements for Windows for Workgroups 3.11 ("the 32-bit file system from our Chicago project").
With the introduction of 32-bit file access and Long File Names in Windows 95, DOS was reduced to the role of a boot loader for Windows.
It was implemented using the VFAT, VCACHE, and IFSMgr
IFSHLP.SYS
IFSHLP.SYS is an MS-DOS device driver included with Microsoft Windows. It enables Windows to make direct file system calls bypassing MS-DOS methods and use native 32-bit file access for both local and network devices...
VxD
VxD
VxD is the device driver model used in Microsoft Windows/386, the 386 enhanced mode of Windows 3.x, Windows 9x, and to some extend also by the Novell DOS 7, OpenDOS 7.01, and DR-DOS 7.02 multitasker...
drivers.
Also, it should not be confused with 32-bit disk access
32-bit Disk Access
32-bit Disk Access refers to a special disk access and caching mode available in older, MS-DOS-based Microsoft Windows operating systems. It was a set of protected mode device drivers that worked together to enhance the system's BIOS...
. Although both technologies are similar, 32-bit disk access (also known as FastDisk) pre-dates Windows for Workgroups 3.11. 32-bit file access provided a 32-bit code path for Windows to directly access the disk bus by intercepting the MS-DOS
MS-DOS
MS-DOS is an operating system for x86-based personal computers. It was the most commonly used member of the DOS family of operating systems, and was the main operating system for IBM PC compatible personal computers during the 1980s to the mid 1990s, until it was gradually superseded by operating...
Int 21H services while remaining in 386 protected mode
Protected mode
In computing, protected mode, also called protected virtual address mode, is an operational mode of x86-compatible central processing units...
and at CPU speeds, rather than handling the Int 21H services in real mode by MS-DOS. 32-bit disk access offers relatively less performance and is less likely to work on many computers than 32-bit file access. 32-bit file access does not need 32-bit disk access.
External links
- MS Windows 32-Bit File Access Meta-FAQ
- 32-bit file access FAQs
- Explanation of SMARTDRV & 32-bit disk access from Microsoft
- Windows for Workgroups 3.11 FAQs
- http://pclt.cis.yale.edu/pclt/OPSYS/WFWG311.HTM