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 virtual memory, paging and safe multi-taskin ...

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 ran as a shell on top of MS-DOS. Codenamed Janus, Windows 3. ...

3.11, which replaced

SmartDrive SmartDrive (or SMARTDRV) is a disk caching program shipped with MS-DOS versions 4.01 through 6.22 and Windows 3.0 through Windows 3.11. It improves data transfer rates by storing frequently accessed data in random-access memory (RAM). Early ...

(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 o ...

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 firmware used to provide runtime services for operating systems and programs and to perform hardware initialization during the b ...

or (preferably) 32-bit disk access (Windows-native protected mode disk drivers). This feature was a

backport Backporting is the action of taking parts from a newer version of a software system or software component and porting them to an older version of the same software. It forms part of the maintenance step in a software development process, and it is ...

from the then-unreleased

Windows 95 Windows 95 is a consumer-oriented operating system developed by Microsoft as part of its Windows 9x family of operating systems. The first operating system in the 9x family, it is the successor to Windows 3.1x, and was released to manufacturi ...

, 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 boot manager and bootstrap loader, is a computer program that is responsible for booting a computer. When a computer is turned off, its softwareincluding operating systems, application code, a ...

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

3.11. 32-bit file access provided a 32-bit code path for Windows to directly access the disk bus by intercepting the

Int 21H services while remaining in 386

, 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

* https://web.archive.org/web/20070324064925/http://pclt.cis.yale.edu/pclt/OPSYS/WFWG311.HTM {{windows-stub Windows architecture

See also

External links