Geniac was an educational toy sold as a mechanical computer designed and marketed by Edmund Berkeley , with Oliver Garfield from 1955 to 1958, but with Garfield continuing without Berkeley through the 1960s. The name stood for "Genius Almost-automatic Computer" but suggests a portmanteau of genius and ENIAC (the first fully electronic general-purpose computer).
17-458: The Geniac kit consisted of a wedge-shaped case, a console panel, and nearly 400 other parts available for assembly. It was powered by a flashlight battery. Basically a rotary switch construction set, the Geniac contained six perforated masonite disks, into the back of which brass jumpers could be inserted. The jumpers made electrical connections between slotted brass bolt heads sitting out from
34-439: A detent mechanism so it "clicks" from one active position to another rather than stalls in an intermediate position. Thus a rotary switch provides greater pole and throw capabilities than simpler switches do. Rotary switches were used as channel selectors on television receivers until the early 1970s, as range selectors on electrical metering equipment, as band selectors on multi-band radios, etc. Modern rotary switches use
51-438: A "star wheel" mechanism to provide the switching positions, such as at every 30, 45, 60, or 90 degrees. Nylon cams are then mounted behind this mechanism and spring-loaded electrical contacts slide around these cams. The cams are notched or cut where the contact should close to complete an electrical circuit. Some rotary switches are user-configurable in relation to the number of positions. A special toothed washer that sits below
68-400: A contact for the "spoke" through which any one of a number of different electrical circuits can be connected to the rotor. The switch is layered to allow the use of multiple poles; each layer is equivalent to one pole. Alternatively the rotation can be limited to a fraction (half; third etc.) of a circle and then each layer can have multiple (two; three etc.) poles. Usually, such a switch has
85-475: A notch. Following this, the lever drops into the next notch and the next et cetera as the wheel or shaft continues to spin. The angle of the backside of the notch is severe (usually 90 degrees or greater to the end of the lever) so that the lever cannot be pushed up or out of the notch if wheel attempts to turn in the opposite direction. The lever is jammed between the back of the notch and its pivot point, stopping movement in that direction against any force that
102-408: A small gravity - or spring -actuated lever paired with a notched wheel. The lever is mounted on a pivot point in proximity to the wheel . The vertical angle of the sides of the notches that face the direction of rotation desired is generally very acute (45 degrees or less), so that as the wheel rotates in that direction, the end of the lever is easily lifted or pushed out and over the top of
119-402: A switch was turned to one of two "on" positions, setting a circuit segment; for each "b" answer, the other "on" position. The circuitry sensed the cumulative effect of the switch positions, the circuit being completed, and a "more masculine" or "more feminine" bulb lit, once three masculine or three feminine answers were recorded. Widely advertised in magazines such as Galaxy Science Fiction ,
136-468: Is a mechanical or magnetic means to resist or arrest the movement of a mechanical device . Such a device can be anything ranging from a simple metal pin to a machine. The term is also used for the method involved. Magnetic detents are most often used to divide a shaft rotation into discrete increments . Magnetic detents are inherent in some types of electric motors, most often stepper motors . The ratchet -and- pawl design arrests movements by employing
153-423: Is a switch operated by rotation. These are often chosen when more than 2 positions are needed, such as a three-speed fan or a CB radio with multiple frequencies of reception or "channels". A rotary switch consists of a spindle or " rotor " that has a contact arm or "spoke" which projects from its surface like a cam . It has an array of terminals, arranged in a circle around the rotor, each of which serves as
170-598: The Geniac provided many youths with their first hands-on introduction to computer concepts and Boolean logic. A nearly identical product, called Brainiac , was introduced in 1958 by Edmund Berkeley, after he had a falling out with Oliver Garfield. Oliver Garfield also sold the Otis King's Patent Calculator , a helical slide rule , under the Geniac brand. Initially he resold the ones manufactured by Carbic, Ltd., but his later products had no serial numbers so were probably his own version. Rotary switch A rotary switch
187-456: The holding nut can be positioned so that the tooth is inserted into one of a number of slots in a way that limits the number of positions available for selection. For example, if only four positions are required on a twelve position switch, the washer can be positioned so that only four switching positions can be selected when in use. This electricity-related article is a stub . You can help Misplaced Pages by expanding it . Detent A detent
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#1732858447835204-456: The jumpers on the back panel, a task advertised as taking only a few minutes. With this basic setup Geniac could use combinational logic only, its outputs depending entirely on inputs manually set. It had no active elements at all – no relays , tubes , or transistors – to allow a machine state to automatically influence subsequent states. Thus, Geniac didn't have memory and couldn't solve problems using sequential logic . All sequencing
221-445: The materials used can withstand. The wheel has little resistance moving in the direction desired, other than that required to lift or push the lever over the next notch. To resist movement (or when creating incremental steps), methods are employed which include a spring-loaded ball detent that locates in small incremental depressions, or a piece of spring steel that snaps into position on flat surfaces or shallow notches milled into
238-407: The shaft or wheel. Stepper motors rely on magnetic detents to retain step location when winding power is removed. They are well suited to be used in printers and numerical control (CNC) devices. A well-known example of a detent can be seen on the popular game show Wheel of Fortune , which employs rubber flippers to help disambiguate on which wedge the wheel has stopped after being spun by
255-412: The similarly perforated masonite back panel. To the bolts were attached wires behind the panel. The circuit comprised a battery, such wires from it to, and between, switch positions, wires from the switches to indicator flashlight bulbs set along the panel's middle, and return wires to the battery to complete the circuit. Setting up Geniac to solve a new problem or perform a new operation involved rewiring
272-460: The subject, A Symbolic Analysis of Relay and Switching Circuits , was also included. A typical project was a primitive "Masculine–Feminine Testing Machine". The user was instructed to answer five questions related to gender, such as "Which makes a better toy for a child: (a) electric train? (b) a doll with a complete wardrobe?" Having wired five of the six rotary switches and set them to "off" positions, questions could be asked. For each "a" answer,
289-434: Was performed manually by the operator, sometimes following fairly complicated printed directions (turn this wheel in this direction if this light lights, etc.) The main instruction book, as well as a supplementary book of wiring diagrams, gave jumper positions and wiring diagrams for building a number of "machines," which could realize fairly complicated Boolean equations. A copy of Claude Shannon 's groundbreaking thesis in
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