14 Facts About S-100 bus


The S-100 bus was the first industry standard expansion S-100 bus for the microcomputer industry.

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Power supplied on the S-100 bus is bulk unregulated +8 Volt DC and ±16 Volt DC, designed to be regulated on the cards to +5 V, -5 V and +12 V for Intel 8080 CPU IC, ±12 V RS-232 line driver ICs, +12 V for disk drive motors.

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The Sol-20 used a variation that had only a single 8-bit S-100 bus and used the now-unused pins as signal grounds to reduce electronic noise.

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Address S-100 bus is 16-bits wide in the initial implementation and later extended to 24-bits wide.

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Unassigned lines of the original S-100 bus specification were later assigned to support more advanced processors.

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One unassigned line of the S-100 bus then was reassigned to support the non-maskable interrupt request.

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S-100 bus then looked for an inexpensive source of connectors, and he came across a supply of military surplus 100-pin edge connectors.

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The 100-pin S-100 bus was created by an anonymous draftsman, who selected the connector from a parts catalog and arbitrarily assigned signal names to groups of connector pins.

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These companies were forced to refer to the system as the "Altair S-100 bus", and wanted another name in order to avoid referring to their competitor when describing their own system.

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S-100 bus had a beer in his hand and when the plane hit a bump, Melen spilt some the beer on Marsh.

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The first symposium on the S-100 bus, moderated by Jim Warren, was held November 20, 1976 at Diablo Valley College with a panel consisting of Harry Garland, George Morrow, and Lee Felsenstein.

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The success of these computers, which used IBM's own, incompatible S-100 bus architecture, cut deeply into the market for S-100 bus products.

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Banks of S-100 bus computers were used, for example, to process the trades at the Chicago Mercantile Exchange; the United States Air Force deployed S-100 bus machines for their mission planning systems.

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Market for S-100 bus products continued to contract through the early 1990s, as IBM-compatible computers became more capable.

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