IBM 8514/A Graphics Adapter

IBM 8514/A Graphics Adapter

General Info
Release Year	1987
Manufacturer	IBM
Device Category	Video Card
Condition	Working
Identifiers
Model Number	8514/A
Technical Specifications
Memory Capacity	512kb-1024kb
Memory Type	Custom Expansion Card
Expansion Interface	Microchannel
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The IBM 8514/A is a coprocessor driven high resolution graphics card for IBM PS/2 systems with an Microchannel slot with video pass through. The card is capable of outputting 640x480 or 1024x768 with a 16 or 256 value color palette. The high resolution 1024x768 mode outputs video interlaced which is not common for PCs.

Examples

IBM 8514/A Display Adapter
Condition	Working

IBM 8514/A Memory Expansion Kit
Condition	Working

Technical

Video Pass Through

IBM released the 8514/A for the PS/2 Microchannel computers exclusively. These PS/2 systems featured an onboard VGA display adapter. The 8514/A can be installed only in a specific MCA slot that has extra pins on the connector to pass through the onboard video signal. The 8514/A then switches between the onboard and internally generated video signal. The 8514/A cannot be used independently, it does not provide or emulate a Motorola 6845 display controller needed for display text modes.

Because the 8514/A does not provide standard VGA functions it is mapped into a different address space in the computer making both video devices accessible at once. Dual display modes were officially supported on PS/2 machines with an 8514/A installed as a result. One example is AutoCAD which can render the CAD data on the 8514/A and provide a command line on the onboard VGA display.

Coprocessor

The 8514/A was a successor to IBM's Professional Graphics Controller which was for the original PC/XT/AT and added hardware drawing capabilities to offload functions from the CPU. The 8514/A also provides a coprocessor for offloading drawing to its internal framebuffer. IBM did not publish hardware level documentation for the card and instead provided a TSR driver, HDILOAD.EXE , for DOS that developers were intended to use instead. This driver was known as the "Adapter Interface".

Later the card itself would be reverse engineered and cloned by ATI and S3 which lead to the publication of some hardware level access that let developers create custom interfaces to the card. These custom interfaces were not very common though. The only example from the era I know of is Quarterdeck DESQView/X v1.1.

Video Output

The 8514/A is most notably associated with its 1024x768 interlaced output mode. The 8514/A predates VESA standard video modes and the high resolution mode of the card does not have a distinct name. (Though it was succeeded by the IBM XGA card which would output 1024x768 without interlacing, XGA would then be adopted as the name for 1024x768p). The high resolution video has a full vertical refresh rate of 42Hz which was slow enough that users can perceive the flicker of the interlaced display. There is a modern misunderstanding that some displays may have had a slower decaying phosphor that smoothed this flicker. This is a concept from CRT televisions where the nearby lines of the even and odd fields would be visually similar. This is not the case for the kinds of high resolution artificial graphics that computers display and slower phosphors would just lead to blurry video.

The 8514/A can also output directly output at 640x480, this is done to have 256 color color non-interlaced video. This mode is not well known and was uncommon enough that even IBM seemed to have forgotten about it by 1998 in the VLAR-3X8T64 service notes. The 640x480 mode is detected and switched to automatically by supported applications. This is communicated to the software through the Adapter Interface API, the card detects the type of monitor connected to the card by checking which ID pins on the VGA connector are grounded. The pins correspond to different IBM displays of the day and what they support.

Monitor (IBM Model)	Output Resolution	Grounded VGA ID Bits
Monochrome (8503)	640x480*	1**
Color VGA (8512,8513)	640x480	0
Color High Resolution (8514)	1024x768 (interlaced)	0, 2

*The display mode is also monochrome at the BIOS level like MDA

**This display mode is also activated when no ID pins are grounded

Despite this being a supported feature, very few applications utilized 640x480 256 color mode. AutoCAD and PC Paintbrush are two examples that do. Applications using the Adapter Interface API that do not support this mode will continue drawing a 1024x768 image to the card, but only the top left 640x480 section will be output. However, all known examples of software that use custom hardware access do not check this before setting the output mode to 1024x768. This will cause an incompatible video signal to be sent to the display that can cause hardware damage.

History and Legacy

The IBM 8514 display and 8514/A adapter were released a few months after the PS/2 line was first introduced. PS/2s could normally do up to 640x480 resolution at 16 colors. The 8514 was capable of rendering at 1024x768 at 256 colors, though interlaced. This required the use of a special 8514 monitor as well, because the sync rate is incompatible with the normal 8513 color monitor at that resolution. Users of the day found the interlaced video unpleasant and it was criticized much for it. The 8514/A also included a coprocessor capable of handling drawing routines independently. This massively improved performance in supported applications like AutoCAD. But it also improved the performance of another program, Windows. Because so much basic drawing needed to be done constantly, the 8514/a could also significantly speed up Windows while also providing a higher resolution and higher color interface. This was not the first video card with a graphics coprocessor for the PC, or even the first made by IBM. But it was introduced at just the right time alongside Windows with a useful feature set and drivers. The industry saw how the 8514/A could enhance video rendering and there were predictions that it would become a new standard.

This eventually happened and other manufactures cloned its coprocessor functions. The ATI Mach 8 was one notable model, as was the S3 86C911. ATI's solution was more like the original 8514/A as a standalone processor, but they changed the high resolution output to allow progressive scan eliminating the flicker. S3's 86C911 was a single IC integrated solution with a standard VGA card core with the 8514/A clone. ATI would also offer a single card with a Mach 8 and VGA Wonder card merged together as the Graphics Ultra. These cards also built on a growing industry around "Super VGA" cards that were extending the resolution options from the PS/2's onboard VGA controller. They offered 800x600 and varying color depths for different modes. The industry came together to form VESA to standardize resolution timing and sync signals. The cloned 8514/A coprocessor continued to be included with cards even after the 8514/A was discontinued and manufactures eventually stopped mentioning compatibility with in in favor of just mentioning a card's functionality as a "Windows Accelerator". The successor to the 8514/A from IBM was the XGA card which introduced more features that would become standard like a sprite for the mouse cursor. But the 8514/A was the origin of the architecture that powered many cards going into the 1990s.

Photos

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Screenshots

These are screenshots capturing the output of an original IBM 8514/A.

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  Windows 2.1 286 Running on an IBM 8514

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  Windows 2.1 286 Running IBM ImagEdit v2.0 on an IBM 8514 with grey color palette loaded

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  AutoCAD R11 Running on IBM 8514 in 1024x768

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  AutoCAD R11 Running on IBM 8514 in 640x480

Known Supported Applications

There is a very narrow window of time that applications would have natively supported the IBM 8514/A from 1987 to the more widespread adoption of Windows 3 released in 1990. This is on top of targeting PS/2 users, and specifically PS/2 users with the card.

Many applications can use the resolution advantage of the 8514/A, and even more so its clones, through Windows inherently and there would have been less incentive to create a DOS application that can directly use it.

Using Adapter Interface API

• AutoCAD R11
• PC Paintbrush IV Plus
• Microsoft Word 6 for MS-DOS
• Mahjong 8514

Using Direct Hardware

• DESQView/X V1.1
• Fractint
• Windows 2.1 Driver for IBM ImagEdit v2.0
• Windows 3 Driver
• IBM OS/2

Notes:

• Dazzle / Razzle Dazzle - This is a kaleidoscope visualization program that claims to support the 8514/A. The documentation doesn't explain how to activate it and it doesn't start automatically.
• Application Drivers - The ATI Mach 8 / Graphics Ultra came with drivers for working with some applications like Lotus 1-2-3, these are harder to find and test.

External links

• Technical Reference Manual - http://bitsavers.informatik.uni-stuttgart.de/pdf/ibm/pc/cards/8514/S68X-2248-0_Display_Adapter_8514A_Technical_Reference_198704.pdf