M. WINDOWS 95, THE OS THAT CHANGED COMPUTING

Microsoft Windows 95

Today, The Grandma continues preparing new material for her future courses. COVID19 has changed a lor of things in our day-by-day and education tools are some of them. It seems that online formation will be a real option in a closer future affecting to current one directly.

Computer tools are essentials to ensure this kind of formation and it is essential to have good computers, good software and good connections. On a day like today, twenty years ago, Windows 95 was launched. It was a great step and an important event that changed the history of computing and also our computing skills.

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 manufacturing on August 15, 1995, and generally to retail on August 24, 1995.

Windows 95 merged Microsoft's formerly separate MS-DOS and Microsoft Windows products, and featured significant improvements over its predecessor, most notably in the graphical user interface (GUI) and in its simplified plug-and-play features.

There were also major changes made to the core components of the operating system, such as moving from a mainly cooperatively multitasked 16-bit architecture to a 32-bit preemptive multitasking architecture, at least when running only 32-bit protected mode applications.

Accompanied by an extensive marketing campaign, Windows 95 introduced numerous functions and features that were featured in later Windows versions, such as the taskbar, the Start button and the ways the user could navigate.

Three years after its introduction, Windows 95 was followed by Windows 98. Microsoft ended extended support for Windows 95 on December 31, 2001.

More information: Microsoft

The initial design and planning of Windows 95 can be traced back to around March 1992, just around the time before the release of Windows 3.1. At this time, Windows for Workgroups 3.11 and Windows NT 3.1 were still in development and Microsoft's plan for the future was focused on Cairo.

Cairo would be Microsoft's next-generation operating system based on Windows NT, featuring a new user interface and an object-based file system, but it was not planned to be shipped before 1994. However, Cairo would partially ship in late July 1996 in the form of Windows NT 4.0, but without the object-based file system, which would later evolve into WinFS.

Simultaneously with Windows 3.1's release, IBM started shipping OS/2 2.0. Microsoft realized they were in need of an updated version of Windows that could support 32-bit applications and preemptive multitasking, but could still run on low-end hardware (Windows NT did not).

The Grandma & Microsoft Windows 95

So the development of Windows Chicago was started and, as it was planned for a late 1993 release, became known as Windows 93 which was also known as Windows 4.0.

Initially, the decision was made not to include a new user interface, as this was planned for Cairo, and only focus on making installation, configuration, and networking easier.

Windows 93 would ship together with MS-DOS 7.0, offering a more integrated experience to the user and making it pointless for other companies to create DOS clones. MS-DOS 7.0 was in development at that time under the code name Jaguar and could optionally run on top of a Windows 3.1-based 32-bit protected-mode kernel called Cougar in order to better compete with DR-DOS. 

The first version of Chicago's feature specification was finished on September 30, 1992. Cougar was to become Chicago's kernel.

Prior to Windows 95's official release, users in the United States and United Kingdom had an opportunity to participate in the Windows 95 Preview Program. For US$19.95/£19.95, users would receive several 3.5-inch floppy disks that would be used to install Windows 95 either as an upgrade from Windows 3.1x or as a fresh installation.

More information: Forbes

Participants were also given a free preview of The Microsoft Network (MSN), the online service that Microsoft launched with Windows 95.

During the preview period, Microsoft established various electronic distribution points for promotional and technical documentation on Chicago, including a detailed document for media reviewers describing the new system highlights. 

The preview versions expired in November 1995, after which the user would have to purchase their own copy of the final version of Windows 95.

Windows 95 was designed to be maximally compatible with existing MS-DOS and 16-bit Windows programs and device drivers while offering a more stable and better performing system.

Microsoft Windows 95

The Windows 95 architecture is an evolution of Windows for Workgroups' 386 enhanced mode. The lowest level of the operating system consists of a large number of virtual device drivers (VxDs) running in 32-bit protected mode and one or more virtual DOS machines running in virtual 8086 mode.

The virtual device drivers are responsible for handling physical devices, such as video and network cards, emulating virtual devices used by the virtual machines or providing various system services.

The three most important virtual device drivers are:

Virtual Machine Manager (VMM32.VXD)

Responsible for memory management, event handling, interrupt handling, loading and initializing virtual device drivers, creating new virtual machines and thread scheduling.

Configuration Manager (CONFIGMG)

Responsible for implementing Plug and Play functionality; monitoring hardware configuration changes; detecting devices using bus enumerators; and allocating I/O ports, IRQs, DMA channels and memory in a conflict-free fashion.

Installable File System Manager (Input/Output Subsystem)

Coordinates access to supported file systems. Windows 95 initially shipped with support for FAT12, FAT16, the VFAT extension, ISO 9660 (CDFS), Joliet and network redirectors, with later releases supporting FAT32.

 More information: Computer Hope

Access requests to physical media are sent to Input/Output Supervisor, a component responsible for scheduling the requests.

Each physical media has its own device driver: access to the disk is performed by a port driver, while access to a SCSI device is handled by a miniport driver working atop the SCSI layer. Port and miniport drivers perform I/O operations in 32-bit protected mode, bypassing MS-DOS and BIOS, giving a significant performance improvement. In case there is no native Windows driver for a certain storage device, or if a device is forced to run in compatibility mode, the Real Mode Mapper can access it through MS-DOS.

32-bit Windows programs are assigned their own memory segments, which can be adjusted to any desired size. Memory area outside the segment cannot be accessed by a program. If a program crashes, nothing else is harmed. Before this, programs used fixed non-exclusive 64 KB segments.

Microsoft Windows 95

While the 64 KB size was a serious handicap in DOS and Windows 3.x, lack of guarantee of exclusiveness was the cause of stability issues because programs sometimes overwrote each other's segments.

A crashing Windows 3.x program could knock out surrounding processes.

The Win32 API is implemented by three modules, each consisting of a 16-bit and a 32-bit component.

Windows 95 introduced a redesigned shell based around a desktop metaphor; File shortcuts, also known as shell links, were introduced and the desktop was re-purposed to hold shortcuts to applications, files and folders, reminiscent of Mac OS.

In Windows 3.1 the desktop was used to display icons of running applications. In Windows 95, the currently running applications were displayed as buttons on a taskbar across the bottom of the screen. The taskbar also contained a notification area used to display icons for background applications, a volume control and the current time.

The Start menu, invoked by clicking the Start button on the taskbar or by pressing the Windows key, was introduced as an additional means of launching applications or opening documents. While maintaining the program groups used by its predecessor Program Manager, it also displayed applications within cascading sub-menus.

More information: Lucidica

The previous File Manager program was replaced by Windows Explorer and the Explorer-based Control Panel and several other special folders were added such as My Computer, Dial Up Networking, Recycle Bin, Network Neighborhood, My Documents, Recent documents, Fonts, Printers, and My Briefcase among others. AutoRun was introduced for CD drives.

The user interface looked dramatically different from prior versions of Windows, but its design language did not have a special name like Metro or Aqua or Material Design. Internally it was called the new shell and later simply the shell. The subproject within Microsoft to develop the new shell was internally known as Stimpy.

In 1994, Microsoft designers Mark Malamud and Erik Gavriluk approached Brian Eno to compose music for the Windows 95 project. The result was the six-second start-up music-sound of the Windows 95 operating system, The Microsoft Sound and it was first released as a startup sound in May 1995 on Windows 95 May Test Release build 468.

Microsoft Windows 95

When released for Windows 95 and Windows NT 4.0, Internet Explorer 4 came with an optional Windows Desktop Update, which modified the shell to provide several additional updates to Windows Explorer, including a Quick Launch toolbar, and new features integrated with Internet Explorer, such as Active Desktop, which allowed Internet content to be displayed directly on the desktop. Some of the user interface elements introduced in Windows 95, such as the desktop, taskbar, Start menu and Windows Explorer file manager, remained fundamentally unchanged on future versions of Windows.

Windows 95 tried to automate device detection and configuration as much as possible, but could still fall back to manual settings if necessary. During the initial install process of Windows 95, it would attempt to automatically detect all devices installed in the system.

Windows 95 also introduced the Device Manager to clearly indicate which devices were working optimally with correct drivers and configuration, and to allow the user to override automatic Plug and Play-based driver installation with manual options or give a choice of several semi-automatic configurations to try to free up resources for devices that still needed manual configuration.

More information: PC World

Windows 95 followed Windows for Workgroups 3.11 with its lack of support for older, 16-bit x86 processors, thus requiring an Intel 80386 or compatible. While the OS kernel is 32-bit, much code (especially for the user interface) remained 16-bit for performance reasons as well as development time constraints. This had a rather detrimental effect on system stability and led to frequent application crashes.

The introduction of 32-bit file access in Windows for Workgroups 3.11 meant that 16-bit real mode MS-DOS is not used for managing the files while Windows is running, and the earlier introduction of the 32-bit disk access means that the PC BIOS is often no longer used for managing hard disks.

DOS can be used for running old-style drivers for compatibility, but Microsoft discourages using them, as this prevents proper multitasking and impairs system stability. Control Panel allows a user to see which MS-DOS components are used by the system; optimal performance is achieved when they are bypassed.

Microsoft Windows 95

The Windows kernel uses MS-DOS style real-mode drivers in Safe Mode, which exists to allow a user to fix problems relating to loading native, protected-mode drivers.

Official system requirements were an Intel 80386DX CPU of any speed, 4 MB of system RAM and 50–55 MB of hard disk space depending on features selected. These minimal claims were made in order to maximize the available market of Windows 3.1 migrations. This configuration would rely heavily on virtual memory and was only optimal for productive use on single-tasking dedicated workstations. It was possible to run Windows 95 on a 386 SX, but this led to even less acceptable performance due to its 16-bit external data bus. To achieve optimal performance, Microsoft recommended an Intel 80486 or compatible CPU with at least 8 MB of RAM.

Windows 95 may fail to boot on computers with more than approximately 480 MB of memory. In such a case, reducing the file cache size or the size of video memory can help. The theoretical maximum according to Microsoft is 2 GB.

Most copies of Windows 95 were on CD-ROM, but a floppy version could also be had for older machines. The retail floppy disk version of Windows 95 came on 13 DMF formatted floppy disks, while OSR 2.1 doubled the floppy count to 26. Both versions exclude additional software that the CD-ROM version might have featured.

More information: Though

Microsoft Plus! for Windows 95 was also available on floppy disks. DMF was a special 21-sector format that Microsoft used to store 1.68 MB on floppy disks rather than the usual 1.44 MB.

Windows 95 was superseded by Windows 98 and could still be directly upgraded by either Windows 2000 Professional or Windows Me. Office 2000 is the last version of Microsoft Office to be compatible with Windows 95. Similarly, Windows Media Player 7.1, released in May 2001, and DirectX 8.0a, released in February 2001, are the last versions of Windows Media Player and DirectX available for Windows 95, respectively.

On December 31, 2001, Microsoft ended its support for Windows 95, making it an obsolete product per the Microsoft Lifecycle Policy.

Many features that have since become key components of the Microsoft Windows series, such as the Start menu and the taskbar, originated in Windows 95. Neil MacDonald, a Gartner analyst, said that Windows 95 was a quantum leap in difference in technological capability and stability.

Ina Fried of CNET said that by the time Windows 95 was finally ushered off the market in 2001, it had become a fixture on computer desktops around the world.

Even though support for Windows 95 has ended, the software has occasionally remained in use on legacy systems for various purposes.

In addition, some video game enthusiasts choose to use Windows 95 for their legacy system to play old DOS games, although some other versions of Windows such as Windows 98 can also be used for this purpose.

More information: Rare Historical Photos

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