lines/min. The unit prints on standard Artisan Electronics Corporation Physiological Tape Recorder paper. Price: $2,400. 5 Eastmans Road The RP-31 magnetic cassette tape Parsippany, New Jersey 07054 recorder was designed exclusively for Centronics Data recording physiological phenomena. Corporation Digital Printer Three channels of data and one One Wall Street Beckman's new digital printer, channel of audio can be recorded Hudson, New Hampshire 03051 Model 1454, accepts inputs from all simultaneously. The data to be logic forms (MaS, IC, and transistor). recorded may extend from dc to Solid-State Light Emitters The unit has expandable capability of 80 Hz on each of the three channels; For those wanting to try solid-state ]-21 BCD columns and the ability to the single channel of audio may light in circuitry, Monsanto now offers accept inputs from as many as three include physiological parameters to two Answer Kits to help solve different data sources, with up to 16 10,000 Hz or narrative descriptions. problems. The GaAs Lite Answer Kit characters/column. The instrument The Wolff Industries Unit (2485 consists of two MV50 and MV10B red, also prints out in red and black on the Huntington Drive, San Marino, two MV1 amber, and one MV2 green same line and accepts standard California 91108) has data channel GaAs Lites, along with data sheets and calculator or pressure-sensitive paper. input sensitivity of 700 mV/V application notes. Price is $9.95. The The unit weighs 20lbs and, with (25 k ohms, SE). Limit lights indicate Optoisolator Answer Kit contains a optional battery pack, can be taken signals exceeding +.7, +1, or -1 V. MCD2, MCT2, and MCS2 into the field. Price: $1,095. Full-scale signal output level is ± 1 V photocoupled pair with data and (100 ohms, SE). The recorder is priced application information. The price of Beckman Instruments, Inc. at $1,645. this kit is $9.95 also. Order from your Electronic Instruments Division Monsanto distributor or write Schiller Park, Illinois 60176 Monsanto Electronic Special Products, Briefs 10131 Bubb Road, Cupertino, Stroboscope California 95014. The new General Model 1542 BRMI Subscription, Gratis stroboscope uses a xenon lamp whose Lehigh Valley Electronics, Inc., is Tape Cassette rep rate can be varied from 180 to offering a L-year subscription to The Digital Cassette Recorder 3,750 flashes/min. Image illumination Behavior Research Methods' and allows the user to record computer is constant at any flash rate. Flash Instrumentation to all customers who output rates up to 1,200 baud and can duration can be as short as 5 microsec. purchase $500 or more of LVE replay the signals at any time without The reflector confines the light to a equipment during the period February using additional computer time or beam angle of 40 deg. The unit draws 15 through May 15, 1971. storage space. The computer only 9 W from the ac power line. The connection can be broken when Model 1542 is priced at $95. Pocket-Size Minicomputer required, and the data played back one The BR-1018 minicomputer has a frame at a time, a technique analogous General Radio Company plated-wire S-k-word, 1S·bit memory to microfilm retrieval. Price: $850. 300 Baker Avenue and is smaller than a desk telephone. Concord, Massachusetts 01760 Special packaging reduces mainframe, Computer Displays, Inc. memory, and input/output units to 223 Crescent Street Portable Electrocardiograph solid blocks about the size of bars of Waltham, Massachusetts 02154 The Toshiba Micro soap. The computer is advertised as Electrocardiograph is a transistorized, having a repertoire of 43 instructions, Tape Loading Unit alkaline battery powered unit that a multiply time of 33 microsec, and a Moel TP-1369 permits pushbutton weighs 4.8 kg and measures 261 mm divide time of 43 microsec, The loading of programs and data from long, 98 mm wide, and 139 mm high. present price of $30,000 is expected magnetic tape for PDP-8 . Pen deflection is 15 mm minimum for to drop to less than $5,000 when pilot Features of the instrument include a reference input voltage of 1 mY. The production begins in 1971. The 3.7-kHz transfer rate and the ability to time constant is 1.8 sec minimum, and computer is made by Bunker-Ramo simulate a four-track disk by a the warmup duration is 10 sec Corporation, Electronics Systems programmable track-select option. The maximum. Overall frequency Division, Westlake, California 91361. drum is reprogrammabie for programs characteristic: 65%, 0.1-60 Hz up to 60 steps in length. A standard minimum. Discrimination ratio is Decade Counter and Readout Kits cartridge is used in the transport, with 60 dB minimum. Recording paper is Environmental Products (P_O. Box word storage to 265 k. heat sensitive (50 mm wide and 406, Lafayette, Indiana 47902) 20 mm long), and recording speed is markets decade counter and readout Tennecomp Systems, Inc. 25 mm/sec. Lead selection: Standard, kits. The NR-3 Numitron readout and 795 Oak Ridge Turnpike I, II, III, aVr, aVl, vr, V. Price of the decade counter, with all ICs DR 2010 Oak Ridge, Tennessee 32830 unit is $650. readout, and PC board is priced at $16.95. The N5000-C Nixie-type Time Delay Tokyo Shibaura Electric Company, readout and decade counter is $12.95. The Artisan time-delay capsule is a Ltd. The same company advertises ICs. A solid-state two-lead device capable of Export Division SN7400N quad 2 input NAND gate is delaying ac voltage to a load circuit of 1-6, 1-chome, Uchisaiwai-cho listed at $.66, a SN7402N NOR gate is either resistive, inductive, or lamp. Chiyoda-ku, Tokyo, Japan $.88. In transistor-transistor logic Time delays range from 0.1 to 300 sec. (TIL), a 9328 dual 8·bit shift register Recycling time is 100 msec maximum. Distributed by: is priced at $4.95. A 9033 16-bit Three models may be purchased: high-speed memory is $2.95. 18-30 V ac (24 V ac nominal), Danatron 36-60 Vac (48 Vac nominal), and 2021 East Fourth Street New Surplus Digital Readouts 90-135 V ac (115 V ac nominal). Santa Ana, California 92705 New digital readouts are available at

Behav. Res. Meth. & Instru., 1971, Vol. 3 (2) 111 reduced surplus prices. The units were Computer Terminal Corporation 296 Newton Street made by Industrial Electronic 9725 Datapoint Drive Waltham, Massachusetts 02154 Engineers and sold for over $40 each. San Antonio, Texas 78229 The readouts operate on 12-28 V, but Information Displays, Inc. they can easily be converted to 6 V by Computek, Inc. 333 North Bedford Road changing the bulbs at a cost of 143 Albany Street P.O. Box 688 10 cents each. The numerals are !jz in. Cambridge, Massachusetts 02139 Mount Kisco, New York 10549 wide and 1 in. high, and the units have 12 message positions. Conrac Corporation Information International Two formats are available: one has 600 North Rimsdale Avenue 89 Brighton Avenue the numerals 0-9 plus symbols - and Covina, California 91722 Boston, Massachusetts 02134 -; the other has 0-7 plus -, -, 'I'p, and Tx. With a little ingenuity, the format Corning Data Systems Mark Computer Systems, Inc. can be changed by reworking the 3900 Electronics Drive 80 Skyline Drive readily accessible screen. The DR 0·9 Raleigh, North Carolina 27602 Plainview, New York 11803 model is priced at $9.50; DR 0-7 is $6.50. Both are sold by BF Data 100 Corporation Measurement Systems, Inc. Enterprises, P.O. Box 44, Hathorne, 7450 France Avenue, South 523 West Avenue Massachusetts 01937. Minneapolis, Minnesota 55435 Norwalk, Connecticut 06850

Interactive CRT Terminals Data Disc, Inc. Megadata Computer and Interactive CRT terminals for 1275 California Avenue Communications Corporation on-line communication between Palo Alto, California 94304 151·8 West Industry Court computers and users are marketed by Deer Park, New York 11729 the firms listed below: Data Input Devices Route 28 Monitor Displays Adage, Inc. Derry, New Hampshire 03038 An Aydin Company 1079 Commonwealth Avenue 401 Commerce Drive Boston, Massachusetts 02215 Delta Data Systems Corporation Fort Washington, Pennsylvania Woodhaven Industrial Park 19034 American Data Systems Cornwell Heights, Pennsylvania 8851 Mason Street 19020 National Cash Register Canoga Park, California 91306 Dayton, Ohio 45409 Evans and Sutherland Computer Applicon, Inc. Corporation Optical Electronics, Inc. 83 Second Avenue 3 Research Road P.O. Box 11140 Burlington, Massachusetts 01803 Salt Lake City, Utah 84112 Tucson, Arizona 85706

Applied Digital Data Systems, Inc. Foto-Mem, Inc. -Ford Corporation 100 Marcus Boulevard 6 Strathmore Road 1002 Gemini Avenue Hauppauge, New York 11787 Natick, Massachusetts 01760 Houston, Texas 77058

Atlantic Technology Corporation General Electric Princeton Electronics Products, Inc. Somers Point, New Jersey 08244 Information Devices Department P.O. Box 101 4000 N.W. 39th Expressway North Brunswick, New Jersey Beehive Electrotech, Inc. Oklahoma City, Oklahoma 73112 08902 1473 South 6th West Avenue Salt Lake City, Utah 84104 Hazeltine Corporation RCA Computer Systems Division Industrial Products Division Cherry Hill, New Jersey 08034 Bendix Corporation Little Neck, New York 11362 Communications Division Raytheon Company East Joppa Road Hewlett Communications & Data Processing Towson, Maryland 21204 1501 Page Mill Road Operation Palo Alto, California 94303 1415 Providence Highway Bunker-Ramo Corporation Norwood,Massachusetts 02067 Defense Systems Division , Inc. 8433 Fallbrook Avenue Electronic Data Processing Division Sanders Associates, Inc. Canoga Park, California 91304 60 Walnut Street Daniel Webster Highway, South Wellesley Hills, Massachusetts Nashau, New Hampshire 03060 Burroughs Corporation 02181 6017 Second Avenue Spiras Systems, Inc. Detroit, Michigan 48232 Hughes Aircraft Company 332 SecondAvenue 2020 Oceanside Boulevard Waltham, Massachusetts 02154 Computer Devices, Inc. Oceanside, California 92054 10 Sonar Drive Stromberg Datagraphic, Inc. Woburn, Massachusetts 01801 IBM Corporation P.O. Box 2449 112 East Post Road San Diego, California 92112 Computer Displays, Inc. White Plains, New York 10601 223 Crescent Street Sugerman Laboratories, Inc. Waltham, Massachusetts 02154 IMLAC Corporation 295 Northern Boulevard

112 Behav. Res. Meth. & Instru., 1971, Vol. 3 (2) Great Neck, New York 11021 that makes it possible for the NOVA Instruments, Inc., 230 Ferris Avenue, and Supernova computers to emulate White Plains, New York 10603) is a SYS Computer Corporation standard IBM peripheral controllers; pocket-sized, lightweight, 17-75 DiCarolis Court these include the 2840 graphic-display battery-powered instrument for Hackensack, New Jersey 07601 controller, the 2703 communications cardiac work. It is placed on the processor, and the 2803 mag-tape precordium of the subject and, like the Tasker Industries controller. Communications can take electrocardiograph, detects changes in 4561 Colorado Boulevard place via either the System/360 voltage produced by the heart. Instead Los Angeles, California 90030 selector or the multiplexer channel. of displaying them visually, the unit The interface is on a 15-in. square converts them to an audible sound TEC, Inc. printed circuit board to slide into one pattern. The pattern consists of a base 6700 South Washington Avenue of the subsystem slots in the computer frequency modulated by the electrical Eden Prairie, Minnesota 55343 chassis. Data transfer is in the burst output of the heart so that a rise in mode. Burst length ranges from 1 to voltage applied to the sensing Tektronix, Inc. 641 bytes and is under program electrodes of the electrocardiophone P.O. Box 500 control. (ECP) produces a rise in pitch. Beaverton, Oregon 97005 Three %-in.-long electrodes are Lasers for Vision Research permanently attached to the base of Ultronic Systems Corporation In a joint effort, the and the ECP in the correct position for Data Communication Products Optics Laboratory and the use. These are knurled so that Division Department of Ophthalmology at the nonabrasive conductive media may be Mt. Laurel Industrial Park University of Michigan and the Harris used. Weight of the unit is 12 oz, Moorestown, New Jersey 08057 Electro-Optics Center of Radiation, dimensions are 5-7/8 x 2-3/8 x Inc., have used instant holographic 1-1/2 in., and the price is $175. A Video Systems Corporation interferometry to make a contour map stethophone may be plugged into the 7300 North Crescent Boulevard of the retina of the eat's eye. The output pack ($15). Pennsauken, New Jersey 08110 pattern was achieved by combining krypton and argon laser beams when Miniature Rotary Switches Wyle Computer Products recording the holographic image. The Airflyte Electronics Company (56 129 Maryland Street combined beam from the two lasers Hook Road, Bayonne, New Jersey EI Segundo, California 90245 was split and a hologram obtained 07002) are marketing miniature rotary which contained the interference switches designed for use in timing and Xerox Data Systems pattern from the two beams. The positioning devices where angular 701 South Aviation Boulevard interaction between images produced accuracy, repeatability, low torque, EI Segundo, California 90245 by two wavelengths added contour and phaseability between poles are of lines to the holographic image which prime importance. The Low-Cost Power Transistors indicated differences of about 1/50 of Adjusto-Switches have successfully A new line of low-cost power an inch. replaced up to 20 snap-action switches transistors has been announced by The contour holograms require and cams in many low-current Fairchild Semiconductor, 313 higher levels of light than previously applications where minimum Fairchild Drive, Mountain View, used, suggesting possible damage to installation time, zero hysteresis, California 94040. All devices in this the eye. However, the energy levels assembly costs, and space are factors. new transistor family (true npn and involved are more than 10 times lower To specify the proper Adjusto-Switch, pnp complements) operate at collector than maximum safe exposure. the buyer first selects the proper size currents of up to 4 A maximum and (three basic mini sizes are available), have power ratings of 36 W. Voltages Mini Light-Emitting Diode Digital life, current, and torque. Then the range from 40 to 80. The npn Panelmeter switching function is described or complements are listed as 2N5293 Digilin, Inc., of Glendale, California, sketched, and the data forwarded to through 2N5298; the p n p claims to have the smallest, lightest, the factory for the assignment of a complements are numbered 2N6021 and most rugged mini LED-DPM of its part number. throuzh 2N6026. type. The Type 3330 light-emitting Fairchild has also announced diode digital panelmeter measures Minicomputer News substantial price cuts on some 70 dual 1.15 in. high x 2.04 in. wide x 5 in. Westinghouse Electric Corporation's transistors and on the entire line of deep, weighs 8 oz , and doubles as an (1200 West Colonial Drive, Orlando, MSI 9300 TTL integrated circuits. analog-to-digital converter as well as a Florida 32804) 2500 minicomputer is display. The unit automatically scheduled for first delivery in 1971. Printer for Minicomputers zero-adjusts itself. It does so by The basic $9,950 machine has a 4-k Centronics Data Computer grounding its input, comparing input memory expandable to 65 k, with Corporation (One Wall Street, Hudson, to ground, and using the difference 16-bit word length and hardware New Hampshire 03051) is marketing a signal to generate a zero-correction multiply and divide as standard. Core printer that acts as a hard-copy device signal at about 60 times/sec. It is memory cycle time is 850 nsec. for CRTs and minicomputers. The possible to program independently Available software includes Model 101 impact printer runs at 165 selectable decimal points, the holding FORTRAN IV, Basic, real-time characters/sec or 60 132-character of display data and BCD output. monitor executive, program loaders, lines/min. The unit prints on standard Programming readout can be manual. and subroutine library. paper and is priced at $2,400. Computer control, magnetic or The new IBM minicomputer, the punched tape can be used for System/7, is scheduled for initial Minicomputer Interface preprogramming. Present price of the deliveries in November 1971. The Data General Corporation mini LED-DPM is $275. machine features a monolithic main (Southboro, Massachusetts 01772) is memory and logic circuits. The system marketing a general-purpose IBM Cardiophone consists of a processor module, up to System/360 interface unit ($5,000) The Electrocardiophone (Sage 11 input/output modules, and an

Behav. Res. Meth. & Instru., 1971, Vol. 3 (2) 113 IBM 5028 operation station. The 5028 sells for $2,240 and the smallest System/7 configuration is priced at $16,060 (rental is $352/month), including processor, a 2,048-word memory, and one I/O module. Memory is expandable to 16,384 and the processor has a word length of 16 bits. Memory cycle time is 400 nsee, The logic circuits switch in -6 8-12 nsec, The successful Data General minicomputer line (over 700 NOVAs and Supernovas have been installed) has been expanded to include the NOVA 1200, NOVA 800, and the Supernova SC. The NOVA 1200 uses LSI circuits along with a high level of MSI in the central processor. The basic price of $5,450 includes a 4,096-word by 16-bit word core memory, direct memory access (DMA) channel, and a Teletype interface. Cycle time is 1.2 microsec, effectively 2% to 3 times faster than NOVA, and the price is almost one-third less than that of the NOVA. The 1200's central processor is built on a single 15-in. square printed circuit board, as is the 4-k core memory. First deliveries are scheduled over the first 6 months of 1971. The NOVA 800 is a fully parallel Rl 100.Ok Rs 470 c1 6.80 ufd IC 1 uSF771139x minicomputer with an 800-nsec cycle R2 SO.Ok 10 turn pot. R9 2.2k C2 .01 ufd IC2 K:7479 time and is designed for applications R3 3.3k RlO 10.0k C3 .01 ufd Ql 2N1711 R4 LSk Rll lO.Ok with high input/output requirements. RS 4.7k R12 4.7k Cost of the 800 is $6,950 including a R6 l.Sk R 4.7k 13 4096-word by 16-bit core memory, R7 680 riMA channel, and Teletype interface. The Supernova SC has a new 300-nsec Fig. 1. Comparator circuit. all-monolithic memory. Execution time for arithmetic and logical contingent on response amplitude circuit was laid out on a printed circuit instructions is also 300 nsec: a single during a time window may be board. It is advisable to mount this ins truction cycle. The basic controlled by this inexpensive circuit. circuit in a metal box to provide configuration costs $11,900. All three The usual method of accomplishing shielding. The cost of materials is less machines are compatible with each this control requires an amplifier, than $40. other and with NOVA and Supernova. Schmidt trigger, AND gate, flip-flop, Software is common to all, and and a driver. interfaces to peripherals are The comparator circuit shown in THEORY OF OPERATION interchangeable. Fig. 1 requires two integrated circuits, The circuit is in the inhibit stage if Note: There has been a drop in two transistors, and two diodes. the enable input is at a logic "0." The minidisk prices, with the cost per bit Analog inputs varying more than output of the circuit will not change, down as low as 0.06 cents. 20 mV from the set reference voltage regardless of the excursions of the There are now over 75,000 will be detected. The analog input analog input. The circuit is enabled by computers in the U.S. impedance is greater than 50 k ohms. a logic "I" at the enable input. The The analog circuit was capacitively output then may switch to the "on" coupled because of the need for state whenever the analog input Note isolation of the input from a de offset. exceeds the reference voltage, which The unit could be directly coupled if a may be varied by adjusting the Comparator combines frequency response lower than 3 Hz potentiometer on one leg of the was necessary and there was no comparator. The output is an open analog-logic function problem of baseline shift. Logic collector of a transistor. Once the circuits with "0" logic levels between circuit has been set, the transistor will Lloyd J. Frei -4 and -25 V and "1" logic levels be biased "on" until reset. Resetting is University of Iowa between 0 and -1 V may be used for accomplished by applying a logic"1" Iowa City, Iowa 52240 the enable and reset inputs. Examples to the reset input. The enable input of logic circuits which could be used should be returned to a logic "0" Control of events which are are BRS-Foringer and Iconix. The when the reset command is given.

114 Behav. Res. Meth. & Instru., 1971, Vol. 3 (2)