IBM 8514

8514 / A denotes both a graphics accelerator, which was introduced by IBM in 1987 with the IBM PS/2-Serie of computers ( Display Adapter 8514 / A), as well as the associated graphics standard.

Description

The standard 8514 / A is tuned to complement the capabilities of VGA, and uses a fixed resolution of 1024 × 768 pixels (pixel ) - around 2.5 times from VGA (640 × 480 pixels). From a palette of 262,144 colors can be displayed at the same time 256; on monochrome monitors is 8514 / A from 64 shades of gray. In addition, graphics commands are defined for representing vector graphics.

Technology

The original IBM Display Adapter 8514 / A has no own text or VGA capabilities. Instead, these functions are still performed by the VGA graphics hardware that is permanently installed in the then PS/2-Modellen, and passes the image produced through a special slot in the Micro Channel bus to the 8514 / A. The 8514 / A itself only generates an image when the skills are required. As required, the VGA or the 8514/A-Bildausgabe is converted into a signal for the display.

Is considered groundbreaking here until today the concept that an application program to generate an image in 8514/A-Modus not, as previously need to directly access the graphics hardware. Instead, a driver program runs in the background, which introduces the so-called adapter Interface ( AI) for other programs to interface with abstract graphics functions available, which converts it into hardware commands. This characteristic was 8514 / A, or the interface AI, only the standard. It allowed but also other manufacturers, own, compatible products (clones ) to produce, without needing knowledge of the hardware of the original 8514 / A - as long as they provide a for AI of the 8514 / A compatible program available which are usually completely different can control hardware.

The impressive for 1987 combination of resolution and color depth set according to increasing demands on the amount of video memory and the ability to spend its entire contents quickly enough to the screen. The IBM Display Adapter 8514 / A bought this power through the use of interlaced scanning ( " interlacing " ), in which only every other line is displayed at the same time, which could be reduced to the screen the requirements. Since this technique the effective refresh rate but halved to 43.5 Hz, so that the image is perceived as flickering, some manufacturers have later made ​​8514/A-Klone without this process ( " non-interlaced ").

Clones were produced as opposed to the original IBM original, not only for the Micro Channel bus, but are possibly full-fledged graphics cards with own text, VGA, and other functions.

Accessories

The video memory of the IBM Display Adapter 8514 / A is 512 KB in size, which can be represented only 16 colors. In order to actually can display 256 colors simultaneously, a graphic memory expansion to an additional 1 MB is needed.

In keeping with the IBM sales 8514/A-Karte the monitor type 8514, which required 1024 × 768 pixels can display on a 16 "picture tube at 43.5 Hz ( as well as the image modes of VGA hardware ). It can also be any other monitor with VGA connector can be used, which reaches at least the same performance.

Successor

In the fall of 1990, IBM released the successor to the XGA standard, which united both VGA and 8514/A-ähnliche functions in the same hardware. The succession in the graphics accelerators occurred in 1989 at the Image Adapter / A, the highest served claims.