Machine Design

Looking Back

10 YEARS AGO — SEPTEMBE R 24, 1998

New chips open doors for smart cards: Four high-capacity memory chips from Motorola will let developers combine several applications on a single smart card at a cost comparable to today’s single-application cards. The chips, with up to 32k of EEPROM, target card-payment and mobile telecommunications. They are based on a Motorola M68HC05 smartchip core and are produced on 8-in. (200mm) wafers, an industry first for smart chips. Reduced circuit geometries (0.4 and 0.27-micron processes) let designers put more features on each chip.

30 YEA RS AGO — SEPTEMBE R 21, 1978

Widest electrostatic plotter writes with 14,336 nibs: To produce 200-dpi resolution across 72-in.-wide paper, the new Versatec 8272 uses 14,336 electronic writing nibs. The widest high-resolution electrostatic plotter yet manufactured, it draws at 7.5 ft2/min with a maximum dot-to-dot position deviation of 1.5 mils horizontal and 2 mils vertical. An exclusive shaft encoder and servomotor drive provide the accuracy. The encoder determines timing and writing location; the servomotor controls paper movement. Dark, consistent images are made by a toner-control system and dual-array writing head. A turbulent flow-toner system maintains contact between toner and paper.

50 YEA RS AGO — SEPTEMBE R 18, 1958

Gasoline-filled blimp sails deep under the sea: The Navy’s bathyscaph permits safe sea exploration at 20,000-ft depths. The vessel works like a blimp in reverse. Buoyancy is provided by 28,000 gallons of aviation gasoline contained in a thin-walled metal “bag.” As the ship descends, water is taken into the bag, compressing the gasoline and reducing buoyancy. Since internal pressure offsets external pressure, wall thickness of the bag is only 1/3 in. Batteries supply power for propulsion and fail-safe buoyancy controls. In the event of a power failure, electromagnets automatically release all ballast — 10 tons of pellets — and the ship should bob to the surface. Externally mounted electrical apparatus is filled with nonconducting liquids to keep out seawater.



Gasoline-filled blimp

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