PC GRAPHICS

PC Focus: TurboPlick,a PrecisionPointing DeviceBy Richard A. McGrath, Contributing Editor

TurboPuck, from the KA DesignGroup (Oakland, CA), is a 2-Dpointing device that is somewhatlike a mouse, joystick and digitiz-ing tablet—all rolled into singlepackage capable of delivering16,385 x 16,385 resolution. A com-plete $159.59 TurboPuck systemincludes the opto-electronics pack-age, an RS-232 connector cable anddocumentation. If needed, an ex-ternal power supply is available foran additional $20.

The user's interface is a motionhandle which can be moved withina 1.5" rectangular area. Opticalsensors measure the position of thehandle to the nearest 0.010", witha maximum resolution of one partin 16,385 per axis of motion. Thereare three buttons on the housingthat can function like those on amouse, and an optical switch is builtinto the motion handle. When thehandle is pushed down, theTurboPuck senses this change.

Several modes of operation allowyou to change TurboPuck's resolu-tion and type of motion. You canswitch from ASCII to binary out-put under program control or bychanging DIP switches. The DeltaBinary output mode emulatesmouse output and an Absolute Bi-nary output mode is like that pro-vided by small digitizing tablets.

The device includes a module withan opto-mechanical motion assem-bly (Puck Pointer Component)mounted on a small printed circuitboard. The board contains digitaldriver circuitry, a bank of eight DIPswitches, and a microprocessor. Inaddition, there are three micro-switches plus connectors for powerand the serial cable.

Similar modules are available toOEM's for installation into key-boards or instrumentation. Sincethis component is only 0.5" thickand 3.25" square, it can easily befitted into the space normally oc-cupied by the numeric keypad orarrow keys. On the TurboPuck, themotion handle is a gray knob thatsticks up about 0.75" above thehousing. The knob, buttons andhousing can be customized to suita manufacturer's requirements forsize, style or color. On quantity or-ders, any four of the standard spec-trum of baud rates can be provided,up to 19,200 baud.

This pointing device is not lim-ited to cursor movement on personal computers. Applications tomedical scanning equipment andmicropositioners are already beingused in the field. The Puck PointerComponent costs $25 and the mod-ule, including driver circuitry, ispriced at $100.

Distinguishing FeaturesSeveral software features distin-guish the TurboPuck from otherpointing devices. With the help ofan on-board microprocessor, com-puting overhead is removed from thehost as different commands are usedto change the device's characteris-tics. For example: automatic cur-sor positioning permits multiplecursor and window manipulation;a Z command provides full controlof x, y, and z axes; the SPACEcommand changes the workingspace in the range of 10 x 10to 16,384x16,384; and theSTEP command changes binaryor ASCII step size in the rangeof 1 to 127.

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The TurboPuck buttons numbered1,2 and 3 are analogous to mousecontrol buttons. The knob is amotion handle that provides 2-axis positioning and anadditional optical switch.

TurboPuck Specifications

ItemModel '

**«&* ,.„•„., „..,-_.,,»., _ .

'Resolution Range

External Interface. . T - _^.,.;_ ,_.....,

Baud Rate"

Power Consumption"

"Switches

Controlled Areas

"Price"' ""

Values or CharacteristicsTurboPuck 2-D/3-D Position Control

1 Part in 10 variable through I part iri~^16,384

RS-232 •• --" •'; ^ '• • 'Tj

300,1,200,9,600,19,200

n W @ 5.0V {or from pin 11 on RS-232connector)

7.5"x4"x 1"

12oz.

3 push buttons," 1 optical switch in handle 1

x, y, z or theta axes ' Y "

S159.95 (plus optional power supply for.520)

The TurboPuck's optical tech-nology is totally enclosed, andtouted as being impervious to dirt,electrical noise, liquids, brightlight, vibration, or the need for ex-ternal adjustment or calibration.Since there are moving mechani-cal parts elsewhere in the PuckPointer Component, however, youshould not expect the advantagesof a completely sealed or encapsu-lated electronic assembly.

Besides having environmentaladvantages over most mice andjoysticks, the TurboPuck boastsfriendly characteristics that pro-mote ease of use. Its motion handlehas a built-in tracking bias thattends to keep the cursor movinghorizontally. When the handle ispressed down, the tracking biasdisappears to allow easier free-hand sketching or positioning.

Another noteworthy feature is thepotential for 3-D use. By using thesoftware Z command, any two axescan be manipulated simultane-ously and the third axis can be frozen in its last position. Instructionsare provided for assigning the Zfunction to the motion handle's op-tical switch. In this configuration,the z (or theta) axis can be usedwhen the motion handle is presseddown and either the x or y axis isfrozen in its last position. Thus, x-y and either y-z or y-theta position-ing can be controlled from the mo-tion handle. Under these conditions,the z axis can also have a resolu-tion of 10 to 16,384 units.

Programming versatility is as-sured in TurboPuck's design. In thebit-pad tablet mode, each of thethree push buttons can have com-bined actions as well as on/off ac-tion. Both two-at-a-time and shiftedmodes are possible. In combinationwith the optical switch in the mo-tion handle, a total of 16 switchingactions are possible under softwarecontrol.

System InstallationEight DIP switches at one end ofthe housing provide for setting var-ious modes and baud rate. You sim-ply plug in a 5V power supply andRS-232 connector, then look in theUser's Guide to find the proper po-sitions for setting the DIP switches.Calibration is done by moving the

46 COMPUTER GRAPHICS WORLD AUGUST 1985

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Puck Pointer Component, theheart of the positioning device,for OEM custom installations.

motion handle around the limits ofits rectangle. That's all there is toit. Different software commands canbe entered at the keyboard to takeadvantage of TurboPuck's versatil-ity. A dumb terminal or terminalprogram on a PC can be used tocheck proper operation by settingthe TurboPuck in ASCII format viaDIP switches and by pressing but-tons and moving the motion han-dle. The output appears on thescreen as readable characters.

Using TurboPuckI tested TurboPuck with a NOVAMS-DOS computer and Tecmar'sGraphics Master display adaptor at640 x 400 resolution (see PC Fo-cus, June 1985). Software pack-ages included AutoDesk's Auto-CAD-2 vector-based drafting pro-gram (see PC Focus, July 1985) andPC-Paintbrush, a raster-basedpaint program from IMSI.

TurboPuck was configured to em-ulate a Mouse Systems Mouseoperating at 1,200 baud. Noinstallation problems were en-countered with either softwarepackage. The SPACE and STEPcommands were used at factorysettings, which results in about a2" x 3" screen window that reflectsthe TurboPuck's drawing area.When the cursor reaches an edgeof the window, the active area movesor "rates" to a new position wheredrawing can continue.

In a second set of tests, Turbo-Puck was connected to a Liberty 50dumb terminal and the DIPswitches were set in ASCII mode.As the motion handle is moved, co-ordinate values appear on thescreen. TurboPuck responds tovarious input commands by dis-playing different sets of output co-ordinates as the handle is moved.

TurboPuck works smoothly and

easily. The knob on the motionhandle turns to receive finger pres-sure from the controlling move-ments. A device with this level ofaccuracy takes some getting usedto. However, TurboPuck is a inno-vative design for precision posi-tioning, and the Puck PointerComponent is an excellent alter-native to arrow keys.

SummaryTurboPuck is a 2-D or 3-D preci-sion pointing device that canachieve resolutions far in excess ofthe capabilities of most of today'sgraphics systems, and works as ad-vertised without any problems ordisappointments. Resolution can bevaried via software commands from10 x 10 to 16,385 x 16,385, and stepsize can be set anywhere from 1 to127. Two of the x, y and z (or theta)axes can be used simultaneously,and the software allows for switch-ing to a different pair of axes andlocking a previous axis position.Binary and ASCII output modes arepossible, and baud rates of 300,1,200, 9,600 and 19,200 can be setby DIP switches. The TurboPuck'sPuck Pointer Component is avail-able to OEM's for installation incomputer keyboards, industrial in-strumentation, or applications withmedical equipment. Both TurboPuck and the Puck Pointer Com-ponent operate from 5V and use anRS-232 interface. •

AcknowledgmentThanks to Computrade Co. (San Jose, CA)for the leaner NOVA computer system, anIBM-PC look/work-alike available withfloppy or hard disk, used on this month'sPC Focus test bench.

Richard McGrath owns andmanages Studio 7 Technical Docu-mentation, a technical writing,graphics and consulting businessspecializing in hardware/softwareuser's guides.

PC Focus calls attention to recentand significant contributions in thearea of personal computer graphicshardware or software. Manufactu-rers with products for reviewshould contact:

Richard McGrathStudio 7 Technical Documentation2640 Melendy DriveSan Carlos, CA 94070(415) 595-8401 or 956-6097

48 COMPUTER GRAPHICS WORLD AUGUST 1985