Intel 80287, 80286 manual Upgradability

OVERVIEW OF NUMERIC PROCESSING

A few examples, which show how the 80287 might be used in specific numerics applications, are described below. In many cases, these types of systems have been implemented in the past with minicomputers. The advent of the 80287 brings the size and cost savings of microprocessor technology to these applications for the first time.

•Business data processing-The NPX's ability to accept decimal operands and produce exact decimal results of up to 18 digits greatly simplifies accounting programming. Financial calculations that use power functions can take advantage of the 80287's exponentiation and logarithmic instructions.

Process control-The 80287 solves dynamic range problems automatically, and its extended preci- sion allows control functions to be fine-tuned for more accurate and efficient performance. Control algorithms implemented with the NPX also contribute to improved reliability and safety, while the 80287's speed can be exploited in real-time operations.

Computer numerical control (CNC)-The 80287 can move and position machine tool heads with accuracy in real-time. Axis positioning also benefits from the hardware trigonometric support provided by the 80287.

Robotics-Coupling small size and modest power requirements with powerful computational abili- ties, the NPX is ideal for on-board six-axis positioning.

Navigation-Very small, lightweight, and accurate inertial guidance systems can be implemented with the 80287. Its built-in trigonometric functions can speed and simplify the calculation of position from bearing data.

•Graphics terminals-The 80287 can be used in graphics terminals to locally perform many functions that normally demand the attention of a main computer; these include rotation, scaling, and inter- polation. By also using an 82720 Graphics Display Controller to perform high speed data transfers, very powerful and highly self-sufficient terminals can be built from a relatively small number of 80286 family parts.

Data acquisition-The 80287 can be used to scan, scale, and reduce large quantities of data as it is collected, thereby lowering storage requirements and time required to process the data for analysis.

The preceding examples are oriented toward traditional numerics applications. There are, in addition, many other types of systems that do not appear to the end user as computational, but can employ the 80287 to advantage. Indeed, the 80287 presents the imaginative system designer with an opportunity similar to that created by the introduction of the microprocessor itself. Many applications can be viewed as numerically-based if sufficient computational power is available to support this view. This is analo- gous to the thousands of successful products that have been built around "buried" microprocessors, even though the products themselves bear little resemblance to computers.

Upgradability

The architecture of the 80286 CPU is specifically adapted to allow easy upgradability to use an 80287, simply by plugging in the 80287 NPX. For this reason, designers of 80286 systems may wish to incor- porate the 80287 NPX into their designs in order to offer two levels of price and performance at little

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Two features of the 80286 CPU make the design and support of upgradable 80286 systems particularly simple:

•The 80286 can be programmed to recognize the presence of an 80287 NPX; that is, software can recognize whether it is running on an 80286 or an 80287 system.

After determining whether the 80287 NPX is available, the 80286 CPU can be instructed to let the NPX execute all numeric instructions. If an 80287 NPX is not available, the 80286 CPU can emulate

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