Intel Corp has formally announced its mid-life kicker for its yet still young but woebegone 80486SX microprocessor: a single-chip upgrade which plugs into the 80487SX co-processor socket, doubling up the internal CPU clock speed of the 16MHz, 20MHz and 25MHz 80486SX in addition to adding back the maths co-processor (CI No 1,785). Once the new processor has been pinned in, the 80486SX becomes defunct, and might just as well be thrown out, or sold second hand – but do this quickly, as Intel is craftily planning to weld in the 80486SX chip onto the next batch of pin grid array package-based boards, so that dislodging the device becomes quite tricky. It is the 80486 microprocessor’s 8Kb on-chip cache, and the modified bus interface unit, that enable clock speed to be doubled internally, without external bus and external memory being affected – those continue to operate at the processor’s original clock speed. Intel hopes that by introducing the new upgrade technology to the 80486SX line, it will differentiate the microprocessor from the 80386 range. (That is, Intel is trying its level best to promote the 80486SX, which has not taken off the way the company had expected, while the 80386 is under growing attack from clonemakers – in fact, the chipmaker is going so far as to launch a television advertising campaign for the ailing 80486SX, put together by Lucas Films, Shoot One, to be shown on December 9 around the UK TV screening of the film, Wall Street.) The added circuitry required for the clock doubler, which will be available in production quantities sometime next year, is accommodated by Intel’s planned switch to an 0.8-micron from a 1-micron fabrication process. Next year’s 80486SX will also see the elimination of the disabled maths co-processor, providing cost reductions for OEM customers. While all 80486SX CPUs are ready to take the new upgrade technology when its available next year, the original 80486 processor, which was designed two years ago, has to be tweaked to take the upgrade, though Intel promises that 80486-based hardware vendors are redesigning their machines to comply with the technology in time to be demonstrated at the CeBit exhibition in Hanover next March. The new 50MHz 80486 processor potentially will have the same double-up upgrade capacity as the slower-clock versions, though Intel anticipates some additional problems associated with speeding up to 100MHz, among them the issue of heat dissipation. As to the question of who wants to upgrade, Intel’s Ian Wilson says going by previous trends (80386 upgrades), a good 30% of users chose to move up.
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