Tuesday, October 7, 2008

Intel 8088

The Intel 8088 is an Intel x86 microprocessor based on the 8086, with 16-bit registers and an 8-bit external data bus. It can address up to 1 MB of memory. The 8088 was introduced on July 1, 1979, and was used in the original IBM PC.
The 8088 was targeted at economical systems by allowing the use of 8-bit designs. Large bus width circuit boards were still fairly expensive when it was released. The prefetch queue of the 8088 was shortened to four bytes (as opposed to the 8086's six bytes) and the prefetch algorithm slightly modified to adapt to the narrower bus.
Variants of the 8088 with more than 5 MHz maximum clock frequency, include the 8088-2, which was fabricated in Intels new enhanced nMOS process called HMOS and specified for a maximum frequency of 8 MHz. Later followed the 80C88, a fully static CMOS design, which could operate from DC to 8 MHz. There were also several other, more or less similar, variants from other manufacturers. For instance, the V20 was a slightly faster pin compatible variant of the 8088.
The descendants of the 8088 include the 80188, 80186, 80286, 80386, and 80486 microprocessors which are still in use today. See below for a more complete list.
The most influential microcomputer to use the 8088 was, by far, the IBM PC. The original PC processor ran at a clock frequency of 4.77 MHz (4/3 the NTSC colorburst frequency of 3.579545 MHz). Depending on the model, the Intel 8088 ranged from 0.33 to 0.75 million instructions per second

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