Windows 2.1x
Encyclopedia
Windows 2.1x is a family of Microsoft Windows
graphical user interface
-based operating environment
s.
Windows/286 2.10 and Windows/386 2.10 were released on May 27, 1988, less than a year after the release of Windows 2.0
. These versions can take advantage of the specific features of the Intel
80286
and Intel 80386
processors.
driver
for this purpose. It also includes support for several EMS boards
, although this support is not related to the 80286 processor
. The segmented nature of Windows programs
is quite suited to the usage of EMS, as portions of code and data can be made visible in the first megabyte
of memory accessible to real-mode
programs only when the program using them is given control. Microsoft encouraged users to configure their computers with only 256KB of main memory, leaving the address space from 256-640KB available for dynamic mapping of EMS memory.
Despite its name, Windows/286 was fully operational on an 8088 or 8086 processor. Windows/286 would simply not use the high memory area since none exist on an 8086-class processor; however, EMS
could still be used, if present. A few PC vendors shipped Windows/286 with 8086 hardware; an example was IBM's PS/2
Model 25, which had an option to ship with a "DOS 4.00 and Windows kit" for educational markets, which included word processing and presentation software useful for students, which resulted in some confusion when purchasers of this system received a box labeled Windows/286 with a machine that was definitely less than an 80286.
kernel, above which the GUI
and applications run as a virtual 8086 mode
task. It allowed several MS-DOS programs to run in parallel in "virtual 8086" CPU mode, rather than always suspending background applications. (Windows applications could already run in parallel through cooperative multitasking.) Each DOS application could use as much low memory as is available before Windows is started, minus a few kilobytes of overhead. Windows/386 also provided EMS emulation, using the memory management features of the 80386 to make RAM beyond 640K behave like the banked memory previously only supplied by add-in cards and used by popular DOS applications. (By overwriting the WIN200.BIN file with COMMAND.COM
, it is possible to use the EMS emulation in DOS without starting the Windows GUI.) There was no disk-based virtual memory
, so multiple DOS programs had to fit inside the available physical memory; therefore, Microsoft suggested buying additional memory
and cards if necessary.
Neither of these versions worked with DOS memory managers
like CEMM
or QEMM
or with DOS extender
s, which have their own extended memory management and run in protected mode as well. This was remedied in version 3.0, which is compatible with Virtual Control Program Interface
(VCPI) in "standard mode" and with DOS Protected Mode Interface
(DPMI) in "386 enhanced" mode. Windows 3.0 also had the capability of using the DWEMM Direct Write Enhanced Memory Module. This is what enables the far faster and sleek graphical user interface.
support and faster printing and updated printer drivers.
Windows 2.11 was superseded by Windows 3.0
in May 1990, but supported by Microsoft for twelve years, until December 31, 2001.
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
graphical user interface
Graphical user interface
In computing, a graphical user interface is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand-held devices such as MP3 players, portable media players or gaming devices, household appliances and...
-based operating environment
Operating environment
The operating environment in engineering describes the circumstances surrounding and potentially affecting something that is operating. For example electronic or mechanical equipment may be affected by high temperatures, vibration, dust, and other parameters which comprise the operating...
s.
Windows/286 2.10 and Windows/386 2.10 were released on May 27, 1988, less than a year after the release of Windows 2.0
Windows 2.0
Windows 2.0 is a 16-bit Microsoft Windows GUI-based operating environment that was released on December 9, 1987 and is the successor to Windows 1.0. With Windows 2.1x in 1988, Windows 2.0 was supplemented by Windows/286 and Windows/386...
. These versions can take advantage of the specific features of the Intel
Intel Corporation
Intel Corporation is an American multinational semiconductor chip maker corporation headquartered in Santa Clara, California, United States and the world's largest semiconductor chip maker, based on revenue. It is the inventor of the x86 series of microprocessors, the processors found in most...
80286
Intel 80286
The Intel 80286 , introduced on 1 February 1982, was a 16-bit x86 microprocessor with 134,000 transistors. Like its contemporary simpler cousin, the 80186, it could correctly execute most software written for the earlier Intel 8086 and 8088...
and Intel 80386
Intel 80386
The Intel 80386, also known as the i386, or just 386, was a 32-bit microprocessor introduced by Intel in 1985. The first versions had 275,000 transistors and were used as the central processing unit of many workstations and high-end personal computers of the time...
processors.
Editions
Two editions of Windows 2.1x were released, both of which could take advantage of the Intel processor for which they were designed.Windows/286
Windows/286 takes advantage of the HMA to increase the memory available to Windows programs. It introduced the HIMEM.SYS DOSMS-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...
driver
Device driver
In computing, a device driver or software driver is a computer program allowing higher-level computer programs to interact with a hardware device....
for this purpose. It also includes support for several EMS boards
Expanded memory
In DOS memory management, expanded memory is a system of bank switching introduced April 24, 1985 that provided additional memory to DOS programs beyond the limit of conventional memory. Expanded memory uses parts of the address space normally dedicated to communication with peripherals for program...
, although this support is not related to the 80286 processor
Intel 80286
The Intel 80286 , introduced on 1 February 1982, was a 16-bit x86 microprocessor with 134,000 transistors. Like its contemporary simpler cousin, the 80186, it could correctly execute most software written for the earlier Intel 8086 and 8088...
. The segmented nature of Windows programs
Computer program
A computer program is a sequence of instructions written to perform a specified task with a computer. A computer requires programs to function, typically executing the program's instructions in a central processor. The program has an executable form that the computer can use directly to execute...
is quite suited to the usage of EMS, as portions of code and data can be made visible in the first megabyte
Megabyte
The megabyte is a multiple of the unit byte for digital information storage or transmission with two different values depending on context: bytes generally for computer memory; and one million bytes generally for computer storage. The IEEE Standards Board has decided that "Mega will mean 1 000...
of memory accessible to real-mode
Real mode
Real mode, also called real address mode, is an operating mode of 80286 and later x86-compatible CPUs. Real mode is characterized by a 20 bit segmented memory address space and unlimited direct software access to all memory, I/O addresses and peripheral hardware...
programs only when the program using them is given control. Microsoft encouraged users to configure their computers with only 256KB of main memory, leaving the address space from 256-640KB available for dynamic mapping of EMS memory.
Despite its name, Windows/286 was fully operational on an 8088 or 8086 processor. Windows/286 would simply not use the high memory area since none exist on an 8086-class processor; however, EMS
Expanded memory
In DOS memory management, expanded memory is a system of bank switching introduced April 24, 1985 that provided additional memory to DOS programs beyond the limit of conventional memory. Expanded memory uses parts of the address space normally dedicated to communication with peripherals for program...
could still be used, if present. A few PC vendors shipped Windows/286 with 8086 hardware; an example was IBM's PS/2
IBM Personal System/2
The Personal System/2 or PS/2 was IBM's third generation of personal computers. The PS/2 line, released to the public in 1987, was created by IBM in an attempt to recapture control of the PC market by introducing an advanced proprietary architecture...
Model 25, which had an option to ship with a "DOS 4.00 and Windows kit" for educational markets, which included word processing and presentation software useful for students, which resulted in some confusion when purchasers of this system received a box labeled Windows/286 with a machine that was definitely less than an 80286.
Windows/386
Windows/386 was much more advanced than its predecessor. It introduced a protected modeProtected mode
In computing, protected mode, also called protected virtual address mode, is an operational mode of x86-compatible central processing units...
kernel, above which the GUI
Graphical user interface
In computing, a graphical user interface is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand-held devices such as MP3 players, portable media players or gaming devices, household appliances and...
and applications run as a virtual 8086 mode
Virtual 8086 mode
In the 80386 microprocessor and later, virtual 8086 mode allows the execution of real mode applications that are incapable of running directly in protected mode while the processor is running a protected mode operating system.VM86 mode uses a segmentation scheme identical to that of real mode In...
task. It allowed several MS-DOS programs to run in parallel in "virtual 8086" CPU mode, rather than always suspending background applications. (Windows applications could already run in parallel through cooperative multitasking.) Each DOS application could use as much low memory as is available before Windows is started, minus a few kilobytes of overhead. Windows/386 also provided EMS emulation, using the memory management features of the 80386 to make RAM beyond 640K behave like the banked memory previously only supplied by add-in cards and used by popular DOS applications. (By overwriting the WIN200.BIN file with COMMAND.COM
COMMAND.COM
COMMAND.COM is the filename of the default operating system shell for DOS operating systems and the default command line interpreter on Windows 95, Windows 98 and Windows Me...
, it is possible to use the EMS emulation in DOS without starting the Windows GUI.) There was no disk-based virtual memory
Virtual memory
In computing, virtual memory is a memory management technique developed for multitasking kernels. This technique virtualizes a computer architecture's various forms of computer data storage , allowing a program to be designed as though there is only one kind of memory, "virtual" memory, which...
, so multiple DOS programs had to fit inside the available physical memory; therefore, Microsoft suggested buying additional memory
Ram
-Animals:*Ram, an uncastrated male sheep*Ram cichlid, a species of freshwater fish endemic to Colombia and Venezuela-Military:*Battering ram*Ramming, a military tactic in which one vehicle runs into another...
and cards if necessary.
Neither of these versions worked with DOS memory managers
DOS memory management
In IBM PC compatible computing, DOS memory management refers to software and techniques employed to give applications access to more than 640K of "conventional memory". The 640kB limit was specific to the IBM PC and close compatibles; other machines running MS-DOS had different limits, for example...
like CEMM
CEMM
CEMM, for Compaq Expanded Memory Manager was the first so-called PC "memory manager" for Intel 80386 CPUs, able to transform "XMS" extended memory into "EMS" expanded memory by using the virtual memory features and the virtual 8086 mode of the CPU....
or QEMM
QEMM
Quarterdeck Expanded Memory Manager , was a memory manager produced by Quarterdeck Office Systems in the late 1980s through late 1990s. It was the most popular memory manager for the MS-DOS and other DOS operating systems.-QEMM product ranges:QRAM: A memory manager for 286 or higher CPU. It...
or with DOS extender
DOS extender
A DOS extender is a computer software program which enables software to run under a protected mode environment even though the host operating system is only capable of operating in real mode....
s, which have their own extended memory management and run in protected mode as well. This was remedied in version 3.0, which is compatible with Virtual Control Program Interface
Virtual Control Program Interface
In computing, the Virtual Control Program Interface is a specification published in 1989 by Phar Lap Software that allows a DOS program to run in protected mode, granting access to many features of the processor not available in real mode...
(VCPI) in "standard mode" and with DOS Protected Mode Interface
DOS Protected Mode Interface
In computing, the DOS Protected Mode Interface is a specification introduced in 1989 which allows a DOS program to run in protected mode, giving access to many features of the processor not available in real mode...
(DPMI) in "386 enhanced" mode. Windows 3.0 also had the capability of using the DWEMM Direct Write Enhanced Memory Module. This is what enables the far faster and sleek graphical user interface.
Windows 2.11
On March 13, 1989, Windows 2.11 was released in Windows/286 and Windows/386 editions, with some minor changes in memory management, AppleTalkAppleTalk
AppleTalk is a proprietary suite of protocols developed by Apple Inc. for networking computers. It was included in the original Macintosh released in 1984, but is now unsupported as of the release of Mac OS X v10.6 in 2009 in favor of TCP/IP networking...
support and faster printing and updated printer drivers.
Windows 2.11 was superseded by Windows 3.0
Windows 3.0
Windows 3.0, a graphical environment, is the third major release of Microsoft Windows, and was released on 22 May 1990. It became the first widely successful version of Windows and a rival to Apple Macintosh and the Commodore Amiga on the GUI front...
in May 1990, but supported by Microsoft for twelve years, until December 31, 2001.
Further reading
- PC MagazinePC MagazinePC Magazine is a computer magazine published by Ziff Davis Publishing Holdings Inc. A print edition was published from 1982 to January 2009...
. 20 Years of Windows Solutions – Windows 286 & 386.