32-bit file access refers to the higher performance,
protected mode
In computing, protected mode, also called protected virtual address mode, is an operational mode of x86-compatible central processing units (CPUs). It allows system software to use features such as Memory_segmentation, segmentation, virtual mem ...
disk caching method introduced in
Windows for Workgroups
Windows 3.1 is a major release of Microsoft Windows. It was released to manufacturing on April 6, 1992, as a successor to Windows 3.0. Like its predecessors, the Windows 3.1 series run as a Shell (computing), shell on top of MS-DOS; it was t ...
3.11, which replaced
SmartDrive (Smartdrv). It bypassed
MS-DOS
MS-DOS ( ; acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few op ...
and directly accessed the disk, either via the
BIOS
In computing, BIOS (, ; Basic Input/Output System, also known as the System BIOS, ROM BIOS, BIOS ROM or PC BIOS) is a type of firmware used to provide runtime services for operating systems and programs and to perform hardware initialization d ...
or (preferably)
32-bit disk access (Windows-native protected mode disk drivers). This feature was a
backport from the then-unreleased
Windows 95
Windows 95 is a consumer-oriented operating system developed by Microsoft and the first of its Windows 9x family of operating systems, released to manufacturing on July 14, 1995, and generally to retail on August 24, 1995. Windows 95 merged ...
, 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
A bootloader, also spelled as boot loader or called bootstrap loader, is a computer program that is responsible for booting a computer and booting an operating system. If it also provides an interactive menu with multiple boot choices then it's o ...
for Windows. However, it was still possible to boot Windows 95 into a pure real-mode DOS system mode.
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
Windows 3.1 is a major release of Microsoft Windows. It was released to manufacturing on April 6, 1992, as a successor to Windows 3.0. Like its predecessors, the Windows 3.1 series run as a Shell (computing), shell on top of MS-DOS; it was t ...
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 ( ; acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few op ...
Int 21H services while remaining in 386
protected mode
In computing, protected mode, also called protected virtual address mode, is an operational mode of x86-compatible central processing units (CPUs). It allows system software to use features such as Memory_segmentation, segmentation, virtual mem ...
, 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.
See also
*
32-bit disk access
*
IFSHLP.SYS
The Installable File System (IFS) is a filesystem API in MS-DOS/PC DOS 4.x, IBM OS/2 and Microsoft Windows that enables the operating system to recognize and load software driver, drivers for file systems.
History
When IBM and Microsoft were co- ...
External links
*
32-bit file access FAQs* https://web.archive.org/web/20070324064925/http://pclt.cis.yale.edu/pclt/OPSYS/WFWG311.HTM
{{windows-stub
Windows architecture