SmartDrive (or SMARTDRV) is a disk caching program shipped with

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 ...

versions 4.01 through 6.22 and

Windows 3.0 Windows 3.0 is the third major release of Microsoft Windows, launched on May 22, 1990. It introduces a new graphical user interface (GUI) that represents applications as clickable icons, instead of the list of file names in its predecessors. ...

through Windows 3.11. It improves data transfer rates by storing frequently accessed data in

random-access memory Random-access memory (RAM; ) is a form of Computer memory, electronic computer memory that can be read and changed in any order, typically used to store working Data (computing), data and machine code. A random-access memory device allows ...

(RAM). Early versions of SmartDrive were loaded through a

device driver In the context of an operating system, a device driver is a computer program that operates or controls a particular type of device that is attached to a computer or automaton. A driver provides a software interface to hardware devices, enabli ...

named . Versions 4.0 and later were loaded through an

executable In computer science, executable code, an executable file, or an executable program, sometimes simply referred to as an executable or binary, causes a computer "to perform indicated tasks according to encoded instruction (computer science), in ...

file named , which could be run at user's discretion or at boot time via . However, also includes a double-buffering driver that should be loaded through . Version 4.0 also introduced

32-bit disk access 32-bit Disk Access (also known as ''FastDisk'') 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 take advant ...

and could reduce its footprint in

conventional memory In DOS memory management, conventional memory, also called base memory, is the first 640 kilobytes of the memory on IBM PC or compatible systems. It is the read-write memory directly addressable by the processor for use by the operating system ...

(the first 640 kilobytes of memory which was critical to

DOS DOS (, ) is a family of disk-based operating systems for IBM PC compatible computers. The DOS family primarily consists of IBM PC DOS and a rebranded version, Microsoft's MS-DOS, both of which were introduced in 1981. Later compatible syste ...

) by running in

upper memory area In DOS memory management, the upper memory area (UMA) is the memory between the addresses of 640 KB and 1024 KB ( 0xA0000–0xFFFFF) in an IBM PC or compatible. IBM reserved the uppermost 384 KB of the 8088 CPU's 1024 KB ...

(the 384 kilobytes of memory located beyond the conventional memory). A cloaked variant of SmartDrive utilizing the

Helix Cloaking DOS Protected Mode Services (DPMS) is a set of extended DOS memory management services to allow DPMS-enabled DOS drivers to load and execute in extended memory and protected mode. Not being a DOS extender by itself, DPMS is a minimal set of ex ...

API An application programming interface (API) is a connection between computers or between computer programs. It is a type of software interface, offering a service to other pieces of software. A document or standard that describes how to build ...

was available from

Helix Software Helix Software Company, Inc. was a New York City based software company founded in October 1986. The company developed software tools and utilities for DOS and Windows. In 1993, Helix licensed some of its memory management technology to Micros ...

. On

Intel 80386 The Intel 386, originally released as the 80386 and later renamed i386, is the third-generation x86 architecture microprocessor from Intel. It was the first 32-bit computing, 32-bit processor in the line, making it a significant evolution in ...

processors, it could run in

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 ...

to reduce its footprint in conventional memory. Microsoft suggests SmartDrive to be used when installing

Windows 2000 Windows 2000 is a major release of the Windows NT operating system developed by Microsoft, targeting the server and business markets. It is the direct successor to Windows NT 4.0, and was Software release life cycle#Release to manufacturing (RT ...

Windows XP Windows XP is a major release of Microsoft's Windows NT operating system. It was released to manufacturing on August 24, 2001, and later to retail on October 25, 2001. It is a direct successor to Windows 2000 for high-end and business users a ...

from MS-DOS to reduce installation time. SmartDrive has been superseded by VCache, which was introduced in

Windows for Workgroups 3.11 Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...

and carried over to

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 ...

Windows 98 Windows 98 is a consumer-oriented operating system developed by Microsoft as part of its Windows 9x family of Microsoft Windows operating systems. It was the second operating system in the 9x line, as the successor to Windows 95. It was Software ...

Windows 98 SE Windows 98 is a consumer-oriented operating system developed by Microsoft as part of its Windows 9x family of Microsoft Windows operating systems. It was the second operating system in the 9x line, as the successor to Windows 95. It was released ...

and

Windows Me Windows Me (Millennium Edition) is an operating system developed by Microsoft as part of its Windows 9x family of Microsoft Windows operating systems. It was the successor to Windows 98, and was released to manufacturing on June 19, 2000, and t ...

. The main advantage of VCache over SmartDrive is its ability to adjust cache size dynamically. However, it tended to take too much RAM in Windows 95; this aspect was improved in Windows 98.

References

{{Reflist Hard disk software DOS software

See also

References