HOUSTON—
Computer-aided design and computer-aided engineering, or
The Compaq Computer Corporation of Houston, whose best-selling machine is powered by the 80386, has estimated that
It is one thing to generate and manipulate complex drawings and quite another to display them with an acceptable level of detail. The same Compaq study found that 70 percent of all
VGA is superior to such previous graphics standards as CGA or EGA, and it is well suited for most business applications. Even so, VGA is just barely adequate for
What is beyond VGA? Some people think the next standard may be 1,024 pels horizontally by 768 vertically, which was first offered by I.B.M.'s 8514/A graphics board. That is a total of 786,432 pels on screen, compared with 307,200 for VGA. In other words, an 8514/A system can display two and a half times more information on screen at once than a VGA system.
I.B.M. introduced the 8514/A two years ago as an expensive option built atop VGA and available only for its Personal System/2 computers. Because the I.B.M. PS/2's that use the 80386 chip - currently the Models 70 and 80 - were not available in volume until about a year ago, the 8514/A market has grown relatively slowly, analysts said.
Then, last month Compaq introduced a similar 1,024 by 768 video option for all the other 80386-based machines - those that adhere to the industry standard, in contrast to I.B.M.'s PS/2 standard.
The Compaq Advanced Graphics System consists of a plug-in board ($1,499) and a high-resolution 16-inch monitor ($1,999). With it, the user can have 16 colors on screen at once, out of a palette of 16.7 million colors. That should be enough choice for anyone.
An optional graphics memory board ($599) permits an increase in the number of available colors to 256, which is useful for anyone trying to produce realistic shading for three-dimensional models. The board adds 512 kilobytes of special memory dedicated to the video system. Thus, for $1,499 to $4,097, a PC using the 80386 microprocessor can be customized to match the performance of much more expensive work stations.
The optional Compaq monitor might not be needed if the computer is already equipped with a high-resolution, multiscanning display for VGA use. Many ''multisync'' monitors, of which the NEC Multisync is the best known, are already capable of scanning at the frequency used by the Compaq Advanced Video Standard and can be adapted for 1,024 by 768 display by replacing a cable. As a result, the Compaq board can be used with many 14- to 20-inch monitors other than Compaq's own.
But engineers do not live by
Compaq asserts that its new Advanced Graphics 1024 Board delivers up to five times the performance of I.B.M.'s 8514/A while running such applications as AutoCAD, the most popular design program for desktop computers. An I.B.M. spokesman declined to comment on Compaq's assertion.
The impressive performance of the Compaq board can be traced to one of its principal components, the Texas Instruments 34010 GSP (graphics system processor) chip, a powerful processor in its own right. The Intel 80386 is a 32-bit engine capable of handling five million instructions per second (MIPS). The 34010 is also a 32-bit, 5 MIPS engine, but it is exclusively dedicated to painting and repainting images on the screen. You may have already seen the previously anonymous 34010 at work, in laser printers, in automobile and aircraft instrument displays, and in shoot-'em-up arcade games.
Because the 34010 takes over the time-consuming graphics chores from the 80386 chip, the overall system performance is increased. That leads to an immediate impact on productivity: Those highly paid engineers are not sitting there twiddling their thumbs.
Texas Instruments is aggressively promoting the 34010 and its software interface, called TIGA, as the new standard for high-resolution PC displays. Whether it can overtake I.B.M.'s 8514/A remains to be seen. One advantage Texas Instruments has is that it is already testing the next generation of its graphics chip, the 34020, which the company says will offer significantly more power. The Compaq Advanced Graphics Color Monitor is described as a non-interlaced display. What is the difference between interlaced and non-interlaced? In the former, the phosphors that make each pel glow are excited by an electron beam that zigzags across the inside of the screen, hitting every other line and then coming back to do the other half. That is the way shoelaces and televisions work. Some people notice a ''flicker'' in such displays.
With a non-interlaced display, each pel is refreshed in one pass. The process is more expensive but it results in less flicker.
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