IBM Personal Computer refers to the line of personal computers using the 80x86 series of processors. While intended to be a business machine, the computer was popular enough and became the standard computer to be used almost everywhere.
Hardware[]
Processor[]
- 8086: The initial 16-bit processor.
- 80286:
- 80386: Started support for 32-bit instructions. (SX versions used a 16-bit data bus.)
- 80486: An improvement on the 386 processor. The 80486DX also included a built-in floating point processor instead of having a separate co-processor.
- Pentium: Added a cache to improve performance of some applications. However, this slowed down the rendering speed of some games (such as Wolfenstein 3D. Later versions of the Pentium chip carried additional instructions to speed up processing. Modern chips also require an attached fan and heat sink.
- AMD x64/Itanium: The latest processors support 64-bit instructions.
Input[]
IBM computers used the keyboard for input, with mice and joysticks being considered optional components. All three devices are external to the main computer, and are plugged in.
The keyboard first used the DIN connection, later being changed to a PS/2, and USB connections.
Mice originally connected to a specialized Bus Interface, but were later modified to attach to a serial port instead. The interface was then changed to the PS/2, and finally USB connections.
Joysticks and gamepads used a 12-pin connection that attached to most sound cards. They were later switched to USB connections.
Display[]
The displays for these computers is normally provided by a video card.
| Color | Palette 0 | Palette 1 |
|---|---|---|
| 0 | Black | Black |
| 1 | Light green | Light cyan |
| 2 | Light red | Light magenta |
| 3 | Yellow | White |
- Color Graphics Adapter (CGA): A 16-color display that initially provided 80x25 text, but was later updated for graphics in 320x200 resultion with 4-colors.
- Enhanced Graphics Adapter (EGA): A 16-color display that allows a resolution of 640x350. Uses a 64-color palette.
- Video Graphics Array (VGA): An improved display that started to allow 256 colours on screen at once; no specific colours were mandated. High resolutions such as 640x400 still only allowed 16 colors.
- Super VGA: An extension to the VGA that allowed 256+ colors on higher resolutions.
- VESA: A specification to standardize the Super VGA, to allow applications to use the higher resolutions without including a large number of display drivers.
- 3D Acceleration: Later display adapters, starting sometime around 1998, included systems to speed up 3D graphics creation.
Audio[]
IBM computers initially included an internal speaker, which produced beeps or low quality sound. While some games could produce digital sound from the speaker, the speaker itself was low quality and generally had no volume control.
Later PCs started to include sound cards to provide better sound quality in multimedia applications.
Memory[]
Initial computers were limited to 640KB of conventional memory.
- The Expanded Memory System (EMS) allowed extra memory to be added by an expansion card.
- The eXtended Memory System (XMS) allowed memory to be addressed to upto 64MB, and later upgraded to 4GB of memory.
Software[]
MS-DOS[]
Initial versions of the operating system provided a minimal interface. You could load applications, but there were no built-in drivers for optional devices such as sound cards or mice. Any drivers needed to be added to the files config.sys or autoexec.bat to be loaded, and in some cases, could be uninstalled if they were the last driver loaded.
Dos normally ran in real-mode, which was limited to 640KB of memory (but had support for EMS or XMS in the later versions.) Some games, such as Doom used protected-mode, which bypassed the 640KB barrier.
Windows[]
Microsoft Windows is a graphical interface for MS-DOS. While it allowed multi-tasking, it was not designed for games as the memory space was intended to be shared among multiple programs.
Windows 95[]
Windows 95 is a standalone operting system, and shortly introduced DirectX. This feature allowed applications to use the video card in nearly the same manner as MS-Dos applications used to.
Windows XP[]
Windows XP is an operating system that added the security features of Windows NT.
Windows Vista[]
Windows Vista is the newer version of Windows XP, and adds the expectation that applications should work properly under limited user accounts. It's UAC function prevents rogue applications from damaging the system, but caused interference with some games when they couldn't write to their main program directory.
Games for Windows Live[]
Games for Windows Live is a program by Microsoft to create a standard on how mainstream video games should behave under modern operating systems.