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Personal Calculator Has Key To Solve Any Equation

1. 1 0 have the same real roots yet one is almost always much easier to solve numerically than the other For instance when f x 6x x 1 the first equation is easier When f x In 6x x the second is easier See Figs 8 In general every equation is one of an infinite family of equivalent equations with the same real roots and some of those equations must be easier to solve than others If your numerical method fails to solve one of those equations it may succeed with another Inaccurate Equations Numerical equation solvers have been known to calculate an equation s root wrongly That cannot happen to SOLVE unless the equation is wrongly calculated which is what happens in the next example This example resembles equations that have to be solved during financial calculations involving interest rates or yields on investments For every p gt 0 the equation Fig 9 The jagged solid line is a graph of the ostensible roots of 1 0 calcu lated carrying ten significant di gits The colored line ss a plot of correct root x 1 to nine signili P cant digits oblained by a re 4 10 arranged calculation DECEMBER 1979 HEWLETT PACKARD JOURNAL 25 Copr 1949 1998 Hewlett Packard Co x h px 0 where h 0 1 and h z 1 2 2 if z 0 has just one root x and 0 lt x lt 1 The colored line in Fig 9 plots this root x against p and shows how smoothly g
2. R P Dolan Editorial Director Howard L Roberts e Managing Editor Richard Dolan e Director Photographer Arvid A Danielson Illustrator Nancy S Vanderbloom e Administrative Services Typography Anne S LoPresti e European Production Manager Dick Leeksma 2 HEWLETT PACKARD JOURNAL DECEMBER 1979 Hewlett Pack Copr 1949 1998 Hewlett Packard Co LJ High Speed Fiber Optic Link Provides Reliable Real Time HP IB Extension on the HP Interface Bus with a computer controller up to 100 metres away This new fiber optic link is fast and has exceptional immunity to severe industrial environments by Robert B Grady OR MANY YEARS systems engineers have strug gled to simplify and standardize the connection of instruments to computers The problem has many aspects including interface circuitry data formats pro tocol functions timing and software related issues In 1975 IEEE standard 488 was adopted defining an inter face system optimized as an interdevice interface for system components in relatively close proximity able to communicate over a contiguous party line bus system It allows users to connect up to fifteen devices to form a sys tem This standard has gained wide acceptance today over 600 devices manufactured by many companies have IE 488 compatibility Hewlett Packard s version of IEEE 488 is called the HP Interface Bus or HP IB The proliferation of devices compa
3. No numerical equation solver could discover those roots Worse perhaps than roots that can t be found are roots that aren t roots Here is an example where the calculator cannot know whether it has solved f x 0 or f x Consider the two functions f x 1 g x and f x t g x c g x where g x and are defined above These two functions have identical calculated values after rounding for every x that can be keyed into the calculator which consequently can t tell one from the other despite the fact that at x 10 3 the first has a pole 10 3 and the second a zero 10 3 0 Starting from straddling initial guesses x 1 and x 10 the solve key finds a root of both equations f x 0 to lie between 3 333333333 and 3 333333334 after only 49 samples The user not the calculator must decide whether the place where f x changes sign is a root of f x O or not A similar decision arises when both initial guesses lie on the same side of 10 3 in which case so ve ultimately finds a root of f x at some huge x with x 3 33 109 where the calculated value of f x underflows to zero That huge x must be regarded as an approximation to x where both functions f 0 The foregoing examples illustrate how our inability to perform cal culations with infinitely many figures makes equation solving difficult What makes equation solving impossible even if rounding errors never happened is our natural desire
4. measurement speed The basic I to V converter circuit type widely used in electronic pico micro and milliam meters is shown in Fig 8 In this circuit all of the input current flows through range resistor RR while negative feedback keeps the amplifier input near zero The amplifier s output impedance is low enough to drive suc ceeding circuits without disturbing the input source Pg In 1000 10000 Vo Va V Voltmeter Lo Fig 8 Basic current to voltage converter uses feedback to maintain the input voltage near zero while the unknown current develops a measurable voltage across range resistor Front Panet Control amp Display HP IB Interface Option Fig 7 Simplified block diagram of Model 4140A the analog controls and the data processing are managed by the microproces sor an M6800 Analog Output Option Successful application of this ait to a picoammeter requires exceptionally high amplifier input impedance and low offset Since gain in an amplifier can be controlled precisely by generous amounts of negative feedback whereas dc offsets not so easily controlled it is common practice to convert a low level dc input to an whose peak to peak excursions are proportional to the dc After amplification to a level where offsets become insignificant the ac is converted back to dc This technique is realized in the 4140A by the amplifier circuit diagrammed in Fig 9 The volt
5. z Zellers James R Dec Feb July May Aug Aug Nov May Dec Nov Dec July Aug Sept Nov Fob Sept Apr Dec June Mar Apr June Aug Nov Sopt Fob Mar May Oct July Aug Mar June Feb May Apr jan Oa Jan July Jan Sept Mar Mar Oct 1979 1979 1979 1979 1879 1878 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1070 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1928 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 Takagi and Minoru Niizaki designed the voltage sources ind Fumiroh Tsuruda and Hisao Yoshino designed the digital section Mechanical Shibata and industrial design by Kazunori Shibata Y was by Yoshimasa Sato designed the accessories We would also lik Takuo Banr evaluation of the whe uch useful advice prototypes and contributions t significant vho made Hitoshi Noguchi Hitoshi Noguchi gradu University in 1961 and joined Yokogawa Electric Won yea working as an genera d to Yokogawa Hewlett Packard in 1964 where he worked on the 4260A Universal Bridge the 4 Capacitance Bridge the 4271A LCR Meter among others before becoming project leader for the 4140A Outside of working hours Hitoshi likes to go hiking and cycl
6. 442854401 is found in 25 seconds The graph of f x on the negative x side is relatively straight so SOLVE works quickly If the first guess is 99 the root is found in 190 seconds fakes longer to get around a sharp bend b With lirst guesses 0 and 2 the root 1 468829255 is found in 30 seconds With first guesses 2 and 4 the root x 1 74375199 is found in 20 seconds Many root finders have trouble finding nearby roots c With first guesses 0 and 2 the double root 1 386277368 is found in 50 seconds Many root finders cannot find a double root at all d Since no root exists soLvEdisplays ERROR With first guesses of 0 and 10 sove displays ERROR 6 in 25 seconds After the error is cleared soLve displays 2 32677 which approximates the place x 299573 where f x takes its minimum value 50 085 y Ka Q 8 0 where K is complicated but very nearly constant when a and both lie close enough to 2 Consequently the secant formula equation 1 improves good approximations to dramatically and it may be iterated repeated after f y has been calculated a and f a may be discarded and a new and better guess 5 calculated from a formula just like equation 1 y v B fyy fy f 3 2 This process repeated constitutes the secant iteration and is the foundation underlying the operation of 22 HEWLETT PACKARD JOURNAL DECEMBER 1979 the SOLVE key A lot could be said about the secant iteration s ultimately rap
7. Sept June Sept Aug May Jan Apr Mar July Sept June July May Aug Aug Nov Aug Feb Feb Feb Aug Jan Apr Sept Tuly Mar Apr Aug Copr 1949 1998 Hewlett Packard Co 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 Plotter Plotter Plotter Disc Drive Programmable Pulse Generator 50 MHz Logic Pattern Generator Spectrum Analyzer 100 Hz 2 5 GHz 2 22 GHz Network Analyzer 4 to 1300 MHz Modulation Analyzer Desktop Computer Plotter AMIFM Test Source Fiber Optic HP IB Link General O Channel Asynchronous Data Communications Controller HP IB Extender Pulmonary Measurement Systems Power Supply Noegeli Andrew H Norimatsu Yoh Nelson David Nelson Loyd V Noguchi Hitoshi Nygaard Richard A Jr P Alan T Parker Kenneth P Peery Dennis L Peikos Wendy R Riebesell G nter Riley Russell B Robinson Claude Jr Royce William G Schlotzhauer Ed O Shaffer Dyke T Slater Michael Smith Richard 1 Sparks Stephon T Stone Peter 5 T Taylor Phillip N Tsai Lung Wen u Ujvarosy Damon R w Wang Scott W Y Ward Michael J Wickliff Robert G Jr Wilson Michael D Wise Donald M Wong Bosco W Wong Daniel T Y Wood Brian M Woodward Scott E
8. V 0o 1000 0 01V steps 0 to 100 0V 0 steps HOLD TIME 0 101999 s 07 8 steps 010 1999 s 1 5 steps STEP DELAY TIME 0 o 10 00 8 001 5 stops 0 1o 1000 s 0 1 stops Vidi ramo rate 0 001 Visto 1 000 Vis 0 00 V s steps CURRENT LIMITING 100 1 mA and 10 mA 10 V A am V g General OPERATING TEMPERATURE 0 C to 40 C RELATIVE HUMIDITY lt 70 at 40 C POWER 100 120 220V 210 240V 5 option DIMENSIONS 426 mm W WEIGHT 142 kg 31 2 Ib ACCESSORY FURNISHED 16053A Test Leads Traxial cable two each BNC BNC cables and one connecton plate OPTIONS 001 Analog Output 1 C 101 HP IB Interface ACCESSORIES AVAILABLE 16053A Test leads 16054A Connection selector 16055A Test future general purpose 16056A Current divider 10 1 10 48 66 Hz 135 A maximum with any 177 mm H 498 mm D 165 7 19 6 in V with pushbutton scaling HIGH SPEED DATA OUTPUT Available with HP IB option Maximum rate 25 ms PRICES IN U S A 4140A 57360 Op 001 325 Opt 101 220 16053 320 intervals 16054A 275 16055A 1250 16056A 140 MANUFACTURING DIVISION YOKOGAWA HEWLETT PACKARD LTD 9 1 Takakura cho Hachioj shi Tokyo Japan 192 DECEMBER 1979 HEWLETT PAC JURNAL 19 Copr 1949 1998 Hewlett Packard Co Personal Calculator Has Key to Solve Any Equation f x 0 The HP 34C is the first handheld calculator to have a built in numerical equation solver That s why one o
9. an LED optical source driven by two current sources one that is normally on and one that is normally off The normally off source is controlled by a gate that is turned on by positive step in the data stream and off about 60 ns later by an inverted and delayed version of the same step Similarly the normally on current source is turned off by a gate in response to negative step and on again about 60 ns later in response to an inverted and delayed version of the step The refresh circuit consists of a retriggerable monostable multivi brator that has a period of about 5 us It is triggered on by either data transition In the absence of a data transition during the refresh period it resets and the resulting transition is steered to the appro priate optical pulse generating circuits by gates controlled by the data input The transition also triggers the multivibrator to start anew refresh cycle All of the transmitter circuits have been designed into a single integrated circuit housed in a low profile module that is physically compatible with conventional dual in line IC packages and that can be mounted directly on printed circuit boards Receiver Module The receiver uses a reverse biased PIN diode as the detector The diode current is proportional to the received optical power The peak value of this current can be between 100 nA and 50 A depending Delon C Hanson Del Hanson earned a BSEE degree from the University of Wisconsin 1
10. and certainly for the foreseeable future Copr 1949 1998 Hewlett Packard Co Four Color Plotters Enhanced for Unattended Operation OUR COLOR GRAPHIC OUTPUT is an element of many applications involving computer or con troller based systems Three HP programm plotters provide this capability for different types of sys tems Model 98 the HP Interface Bus or HP IB and is programmed in a called HP GL Model s based on the RS 2 2 is compatible with systems based on simple graphics langua compatible with syst V 24 interface and is programmed in a binary language Model 7220 is also compatible with RS 232C CCITT V systems but is programmed in HP GL These plotters lor plots on any paper size in or ISO A3 duce high quality mu 285 x 432 mm 11 1 ted paper advance now makes it possible A new integ for these plotters to produce plot after plot without an operator to change paper This new mechanism provides program control of unattended advance operations It is standard feature of Models 98 ind inc n some but not all earlier mode paper advance is useful for repetitive or se output from automated production and g test systems and for unattended graphics op uter site A third application area pies of presentation quality graphs The four color a central cc is providing multiple cc eport presentati
11. at other HP divisions for their support of our compatibility testing Reference 1 Foreword to IEEE Std 488 1978 IEEE Standard Digital Interface for Programmable Instrumentation Robert Grady Bob Grady project manager and firmware designer for the 12050A celebrates his tenth year with HP this month In those ten years he has man aged development of the 2240A Mea surement and Control Processor hardware the HP ATLAS Compiler software for automatic instrument cali bration and systems self test A native of Chicago Illinois Bob received his BSEE degree from Massachusetts Insti tute of Technology in 1965 and his MSEE degree from Stanford University in 1969 He and his wife who is a t programmer analyst at HP have a son anda daughter and live in Los Altos California Bob plays basketball and softball in local city recreation leagues and enjoys mountain vacations hiking camping or skiing SPECIFICATIONS HP Model 12050A Fiber Optic HP IB Link Units HP IB DATA RATE 20 000 bytes s maximum between 12050A units assuming continu ous data transfer Overall system performance is subject to HP IB handshake rates of devices connected o the 12050As the composition of commands and data being sent over the link and tho rate of transmitted errors between 12050A units Typically the error rate between 12050A units wil be low due to the highly secure fiber optic cable transmission medium and in mo
12. low to the device under test Fig 10 shows the output stability when the instrument is on the most sensitive range and Fig 11 shows the step response on the same range The front panel zero offset is implemented digitally When the ZERO button is pressed while the device under test is not connected the displayed value of leakage cur rent or stray capacitance in the case of C V measurements is stored This value is then subtracted from subsequent measurements 1 x 10712 A 1 x 107 A Fig 11 Step response of the Model 4140A under the same conditions as the recording of Fig 10 shows an absence of overshoot and other ambiguities Similar clean response is obtained with the integration time set to and SHORT Voltage Sources The voltage sources are essentially stable power amplifiers driven by a digital to analog converter DAC Sample and hold techniques enable a single 12 bit DAC to drive both outputs and generate the stepped voltages Ramps are generated by an integrator in response to a step supplied by the DAC Fig 12 Ordinarily the linearity of slow ramps is degraded by temperature variations that cause offset voltage drift in the integrator s amplifier One Ramp Rate Ru D ean i m ma ml pni n m mn ji ir Fig 10 Recording demonstrates the stability of the 4140A on its most sensitive range For this test the source resistance was 100 GN and the measurement integ
13. the 12050A during these tests has led to a Fiber optic lin applica hin HP a The 12050A is vicinity of HP IB instrum RFI tests b Numerous 1205 1eers with conve and yide lab eng graphics capabi n sapphire cir 12050A Copr 1949 1998 Hewlett Packard Co large number of HP applications some of which are shown in Fig 8 At the same time it was clear that many disc devices that are interfaced via the HP IB use one feature of the HP IB parallel poll that is not supported by the serially oriented 12050A If those devices were to be used with the 12050A their responses would have to be determined with the HP IB serial poll feature Acknowledgments I want to express particular appreciation to Dick Cook who was responsible for the complete hardware design of the 12050A and who helped investigate and categorize the wide variety of bus conditions we saw during the course of the project Dave Hannebrink and Bill Dwyer also played key roles in maintaining project momentum and en thusiasm Brice Clark helped provide project resources King Wah Yeung designed the power supply Dennis Mitchell designed the 12050A package and Steve Joseph aided with the firmware Thanks to the many others who provided us support throughout the project Special thanks to Virgil Laing Geoff Chance Dave Smith Charlie Martin Nick Kuhn Don Mathiesen Rich Irwin Joe Williams and Allert Ligtenberg
14. the following fiber optic cable products All 39200 Series cables are supplied with preassembled and protested fiber optic connectors SIMPLEX DUPLEX 2 required 1 required system system 39201A 392018 10 fiber optic cable 39202A 382028 25 metre fiber optic cable 39203A 392038 50 fiber optic cable 39204A 39204B 75 metre fiber optic cable 39205A 392058 100 metre fiber optic cable Only one cable length may be used to connect the 12050A units Cable to cable interconnec tions are not permitted PRICE IN U S A 12050 1950 each unit two required per remote site MANUFACTURING DIVISION DATA SYSTEMS DIVISION 11000 Wolfe Road Cupertino California 94014 U S A DECEMBER 1979 HEWLETT PACKARD JOURNAL 9 Copr 1949 1998 Hewlett Packard Co A Picoammeter with Built in Synchronized amp Voltage Sources This new digital picoammeter makes measurements of 15 small current with a resolution of 10 amperes and it provides programmable voltage steps and measurement delays for automatic l V measurements on semiconductors insulation materials capacitors printed circuit boards and other components by Hitoshi Noguchi ONTINUING ADVANCES in technology have in tensified the need for high performance pico ammeters to measure very small currents These measurements are needed not only for evaluation of elec tronic components and electric materials but also for the detection
15. to decide after only finitely many samples of f x whether it never vanishes Any procedure that claims to accomplish this task in all cases can be exposed as a fraud as follows First apply the procedure to solve f x 0 when 1 everywhere and record the finitely many sample arguments x X at which f x was calculated to reach the decision that f x never van ishes Then apply the procedure again to f x x x x x2 x x3 C X x 1 Since both functions f x take exactly the same value 1 at every sample argument the procedure must decide the same way for both both equations f x 0 have no real root But that is visibly not so So equation solving is impossible in general however necessary it may be in particular cases of practical interest Therefore ask not whether sotve can fail rather ask When will it succeed Answer Usually DECEMBER 1979 HEWLETT PACKARD JOURNAL 23 Copr 1949 1998 Hewlett Packard Co Fig 6 n the HP 34C once two samples of f x with opposite signs have been discovered the secant line 1 is bent to 2 whenever necessary to prevent an iterate from escaping out of the shortest interval known to contain a place where f x reverses sign asionally as illustrated in Fig 6 Another small tion to compensate for roundoff in the secant for mula equation 1 protects it from the premature termina tion illustrated in Fig 7 Altho
16. x continue to decline in magnitude SOLVE follows the secant formula equation 1 with two slight amendments One amendment prevents premature termination see Fig 7 The other deals with nearly horizontal secants when very nearly by bending them to force lt Copr 1949 1998 Hewlett Packard Co 100 8 a thereby diminishing the secant iteration s ten dency to run amok when roundoff becomes significant Convergence now cannot be arbitrarily slow As long as successive samples continue to decline in magnitude without changing sign they must decline to a limit at least as fast ultimately as a geometric progression with common ratio 1 2 and usually much faster When samples f x de cline to zero SOLVE finds a root When they decline to a nonzero limit as must happen when f x 1 or other wise declines asymptotically to a nonzero limit as 2 SOLVE discovers that limit and stops with either ERROR 6 meaning no root was found or 9 999999999 109 mean ing overflow in the display A different approach is needed when a new sample fly exhibits neither a different sign nor a diminished mag nitude To avoid the dithering exhibited in Fig 5b SOLVE sets the secant formula equation 2 aside Instead it inter polates a quadratic through the three points a f a 8 1 8 v fty and sets 5 to the place where that quadra lic s derivative vanishes In effect 5 marks the high
17. 0 May 1979 Address extension chip Sept 1979 Air flow measurements 478048 the pulmonary lab July 1979 AMIGO 300 operating system HP 300 Nov 1979 Amplitude modulation measurements 8901A May 1979 Assembly language desktop computer 9835A 1979 Asynchronous data communications 31264A controller Mar 1979 Automatic circuit board testing DTS 70 3060A Dec 1979 Automatic paper advance 98725 72215 72205 X Y plotter B June 1979 BASIC business computer HP 300 Apr 1979 BASIC business computer HP 250 May 1979 BASIC desktop computer 9835A Jan 1979 Battery powered universal 5314A 5315A counter Jan 1979 Bipolar integrated circuit chip MRC Mar 1979 Board test language 9825A 3060A Mar 1979 Board testing automatic DTS 70 3060A Dec 1979 Bus extender fiber optic 12050A Aug 1979 Bus extender telephone compatible 37201 Apr 1979 Business computer entry level HP 250 June 1979 Business computer HP 300 1979 Business computer HP 300 Sept 1979 Business computer HP 3000 Series 33 Dec 1979 Ca HP 34C Apr 1979 Capacitance DLTS Dec 1979 Capacitance voltage measurements 4140A Mar 1979 Circuit board testing automatic DTS 70 3060A Oct 1979 Communications data analyzer 1640A June 1979 Computer business HP 300 July 1979 Computer business HP 300 May 1979 Computer desktop 9835A July 1979 Computer power supply 63312 Apr 1979 Computer small business HP 250 Sept 1979 Computer system low cost HP 3000 Series 33 genera
18. 002 X Y displays Oscillator local synthesized sweeping 8566A P Paper advance automatic X Y plotter Period measurements 98725 72215 72205 5314 5315 Phase modulation measurements 8901A Picoammeter dc voltage source 4140A synchronized Plotter digital X Y 7225A Plotter X Y with paper 98728 72218 72208 advance Pneumotach for pulmonary 478045 measurements Portable universal counters 5314 5315 Power measurements 8901A Power supply computer 63312F Practical Microprocessors coursebook 5036 Pulse generator 50 MHz programmable 8160A Pulse generator logic patterns B170A Pulmonary function measurements 478045 automated Jan jan Sept Nov Jan May Aug Dec Jan Jan Nov July Mar Sept Feb Dec Aug Copr 1949 1998 Hewlett Packard Co 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 R Ramp generator precision synthesizer function generator Ratio measurements Recorder X Y with paper advance Reliability in electronic equipment Remote computer trouble HP 3000 Series 33 shooting 3325A 5314 5315 9872S 7221S 7220S RF modulation measurements B901A RF Network Ana
19. 2 X Y plotter 7225A Y plotters with paper 98728 72218 72208 advance Y YIG tuned mixer 8566A z DECEMBER 1979 HEWLETT PACKARD JOURNAL 17 PART 3 Model Number Index Model HP 34C System 35 DTS 70 HP 250 HP 300 1610A 003 1615A 001 1741A 002 HP 3000 Series 33 3060A 3325A 4140A 4271A B 4274A 4275A 5036A 5314A 5315A B PART 4 Author Amin Dilip A Aue Poter B Babiarz Alec Baird Paul Baskins Douglas 1 Becker John C Bergh Arndt B Blais Maurice R Blankenship Karl M Bronson Barry Brown lames Brubaker Laslie E Burger Roland H gg Frederick W b Terry R David T D Danielson Dan D David Frank K E Edwards Allen P Edwards Richard C Erdmann Robert E Jr F Fanton John L Fenoglio John A Fiedler Francis F Firooz Kamran Forbes Leonard Forbes V Froseth Stanley E G George David M Grady Robert B Product Month Year Calculator Dec 1979 Desktop Computer 9835A May 1979 Digital Test System Mar 1979 Small Business Computer Apr 1979 Computer June 1979 July 1979 Logic State Analyzer Oct 1979 with HP IB Logic Analyzer with HP IB Oct 1979 Oscilloscope Sept 1979 triggered X Y display Computer System Sept 1979 Board Test System Mar 1979 Synthesizer Function Generator Jan 1979 pA Meter Dc Voltage Source Dec 1979 LCR Meter in DLTS System Apr 1979 LCR Meter 100 Hz 100 kH
20. 3d or where appears to be constant Then the calculator displays ERROR 6 while holding a value x in the X register and f x in the Z register for which f y f x 1 at every other guess y that was tried usually at least four guesses on each side of x One of those guesses is in the Y register When this hap pens the calculator user can explore the behavior of f x in the neighborhood of x possibly by pressing SOLVE again to see whether f really is minimal as it is in Fig 3d whether the calculator has been misled by unlucky guesses More about this later So SOLVE is not foolproof Neither is any other equation solver as explained on page 23 How Does SOLVE Compare with Other Root Finders Program libraries for large and small computers and cal culators usually contain root finding programs but none of them works over so wide a range of problems or so conve niently as does the HP 34C s SOLVE key Other root finders are hampered by at least some of the following limitations 1 They insist upon two initial guesses that straddle an odd number of roots SOLVE accepts any guess or two and does what it can to find a root nearby if possible or else farther away They may have to be told in advance how long they are permitted to search lest they search forever Con sequently their search permit may expire after a long search but just moments before they would have found a root SOLVE knows when
21. 9 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1978 1979 Generator pulse programmable 8160A H HP IB extender fiber optic 12050 extender telephone 37201A HP IB interface for logic 1610A 003 1615A 001 analyzers 1 250 250 IMAGE 300 HP 300 In c rcuit board testing 3060A Instrument systems HP IB extender for 37201A Integrated circuit chip bipolar MRC Integrated display system HP 300 Integrated display system HP 300 Integrated injection logic EL Interface bus extender fiber optic 12050A Interface bus extender telephone 37201A Inventory control HP 250 L Language subsystem HP 300 LCR meters multifrequency 4274A 4275A Linear step motor plotter 7225A Logic analyzers HP IB interfaces for 1610 003 1615A 001 Logic pattern generator 8170A Lung function measurements 478048 M Manufacturing reporting HP 250 Microprocessor lab 5036A Microwave spectrum analyzer B566A Modulation analyzer B901A Monitor simulator analyzer for 1640A data communications Multiple register counter MRC chip Multiprogramming executive HP 3000 Series 33 operating system N Network analyzer 4 to 1300 MHz 8754A o Operating system AMIGO 300 HP 300 Operating system MPE III HP 3000 Order entry HP 250 Oscilloscopes selectively blanked 1741A
22. 959 an MEE degree from New York Univer sity 1961 an MS degree in physics 1966 and PhDEE 1967 from the Uni versity of Michigan and an MBA de gree from Golden Gate University 1978 From 1959 to 1964 he was with Bell Telephone Labs and from 1964 to 1967 he was associated with the Elec tron Physics Lab at the Univerity of Michigan He joined HP in 1967 initially working on solid state microwave oscil lators He currently is fiber optic R and D section manager at HP s Optoelec tronics Division Del is an A Y S O soccer referee and a member owner of a 5000 acre recreational ranch in northern California where he vacations with his wife and three children 10 13 16 years camping horse back riding hunting fishing and skiing DECEMBER 1979 HEWLETT PACKARD JOURNAL 5 Copr 1949 1998 Hewlett Packard Co on link length so ALC is used to force the height of the input amplifier s output pulse to be constant under all conditions This also improves the signal to noise ratio under higher drive conditions Be causeofthe inclusion of the ALC circuits no adjustments to the circuit are needed for normal operation The ALC voltage also provides a monitor available at one of the receiver module s output pins of the presence or absence of an optical input signal Comparators with threshold levels at the 25 and 75 points of the bipolar waveform determine whether a data pulse is present and whether it is negative or pos
23. B Cx B e Cx c B f x C Return f x in the X register PRGMC IIDRUN Switch to Run Mode odiis Bod Store C in Register 1 Bod Store C in Register 2 Fig 2 This is an HP 34C program for the function f x C It replaces x by f x in the HP 34C s X register display It is labeled A but labels B 0 1 2 or 3 would serve as well Of course g x 3x 10 and when calculated as prescribed above don t omit the parentheses it is calculated exactly without roundoff throughout 1 x 6 666666666 Con sequently the calculated value of cannot vanish be cause the obvious candidate x 10 3 3 333 cannot be supplied as an argument on an ordinary calculator SOLVE does the sensible thing when asked to solve g x 0 it delivers final guesses 3 333333333 and 2 333334 in the X and Y registers in a few seconds In general when SOLVE finds a root of f x 0 it returns two final guesses x and y in the X and Y registers respectively either x y and f x 0 or else x and y differ in their last 10th significant decimal digit and f x and f y have opposite signs In both cases the 7 register will contain f x On the other hand SOLVE may fail to find a place where s or changes sign possibly because no such Rather than search forever the calculator will stop where f x appears to be stationary near either a local positive minimum of f x as illustrated in Fig
24. DECEMBE BD JOURNAL hp 12050A FIBER OPTIC HP IB LINK HEWLETT PACKARD ENG E AEN S w OPE INTEGRITY MESSAGE IN PROCES REC E P E bd SELF TEST HEWLETT PACKARD JOURNAL Technical Information from the Laboratories of Hewlett Packard Company DECEMBER 1979 Volume 30 e Number 12 Contents High Speed Fiber Optic Link Provides Reliable Real Time HP IB Extension by Robert B Grady Distances up to 100 metres are no longer a barrier to high speed noise immune communications between HP IB instruments and controllers A Ready to Use Fiber Optic Link for Data Communications by Delon C Hanson fiber optic part of the new HP IB extender is a standard HP product A Picoammeter with Built in Synchronized Voltage Sources by Hitoshi Noguchi It measures very low currents and capacitances as functions of voltage if desired for evaluat ing components materials and semiconductor devices 1979 Index Personal Calculator Has Key to Solve Any Equation f x 0 by William M Kahan If you can write a program for your equation this handheld calculator will find the root usually Viewpoints Don Loughry on ANSI IEEE Standard 488 and the HP Interface Bus brief look at the past present and future of the HP IB and how it relates to IEEE 488 Four Color Plotters Enhanced for Unattended Operation by Majid Azmoon Randy A Coverstone and Richard M Kemplin Now three HP plotters can produce
25. L 27 Copr 1949 1998 Hewlett Packard Co oversight in the standard itself The proper correction is an addi tional CSHS controller standby hold state state for the C Function to delay assertion of the ATN attention message thereby preclud ing momentary coexistence of DAV data valid and ATN as viewed by an idle device This correction which pertains only to devices containing the controller function has been approved by the IEEE Standards Board and is expected to be issued shortly as Supple ment A to the standard While the ANSUIEEE 488 interface standard is enjoying consid erable success international standardization activity has pro gressed also IEC International Electrotechnical Commission Pub lication 625 1 entitled Interface System for Programmable Measuring Apparatus is expected by year end It is the equivalent of ANSIIIEEE 488 in all but one respect the connector Interna tional interest in a 25 pin connector has been high and is specified in IEC 625 1 rather than the 24 pin connector of ANSI IEEE 488 Unfortunately the 25 pin connector is used extensively as part of EIA Standard RS employ voltage levels of 25V tablishment of two widely used interface stan e connector but incompatible signal levels 232C for data communications which may not very compatible with circuits Thus 6 dards with the s seemed an inappropriate way for ANSI IEEE standardization in the United States part
26. P IB Connector Fig 1 Model 12050A Fiber Optic Link n transfer data over the HP Interface Bus compatible with ANSI IEEE 488 1978 20 kilobytes per second It performs error detection and automatic re transmission and has powerful in ternal and link testing capabilities EMBER 1979 HEWLETT PACKARD JOURNAL Copr 1949 1998 Hewlett Packard Co 1000 Comput HP 980 Desktop Computer HP 12050A Fiber Optic HP IB Link HP 2240A Measurement and Control Processor Application Measurement and Control Signals to from Sensors Switches Equipment etc Fig 2 in a typical application a 12050A connects a comput er to a group of HP IB instruments up to 100 metres away The fiber optic cable is immune to electrical noise and lightning provides electrical isolation for rejection of common mode signals such as ground potential differences is safe in explo sive environments and can reduce installation costs by eliminating the need for special protective equipment or shielding completely immune to this interference which plays havoc with normal electrical signals Fiber optic transmission also provides isolation to prevent common mode voltage prob lems and is safe in explosive environments The 12050A emphasizes real time operation by continu ously transmitting data at over 20 kilobytes per second and by asserting each service request SRQ at the computer end of
27. System Richard C Edwards Adapting the Multiprogramming Executive to New Hardware Environment Claude Robinson Jr A Friendly Easy to Service Computer Yas Matsui and Manmohan Kohli A Remote Computer Troubleshooting Facility David L Nelson Philosophy of HP 3000 Series 33 Diagnostics James H Holl Controlling Electromagnetic Interference Generated by a Com puter System Daniel Wong Automated Pulmonary Function Measurements Maurice Blais DECEMBER 1979 HEWLETT PACKARD JOURNAL 15 Copr 1949 1998 Hewlett Packard Co and John L Fanton Triggered X Y Oscilloscope Displays P Guy Howard October 1979 Microprocessor Lab Teaches Operation and Troubleshooting Barry Bronson and Michael Slater An Economical Network Analyzer for the 4 to 1300 MHz Range James R Zellers Expanding Logic Analyzer Capabilities by Means of the HP IB Robert G Wickliff Jr and Richard A Nygaard Jr A Serial Data Analyzer for Locating Faults in Decentralized Digital Systems Robert E Erdmann Jr November 1979 Precise Convenient Analysis of Modulated Signals Allen P Edwards IF Filters for the 8901A Modulation Analyzer Andrew H Naegeli A New Type of FM Demodulator Russell B Riley Modulation Analyzer Applications Allen P Edwards Assuring Accuracy in Modulation Measurements Leslie E PART 2 Subject Index Month Year Subject Model A Feb 1979 Accelerometer hybrid Apr 1979 Accounts receivable HP 25
28. Tester David T Crook Brian M Wood Francis F Fiedler Kamran Firooz and Roland H Burger Board Testing with Signature Analysis Kamran Firooz April 1979 A Human Engineered Small Business Computer A Peter Hamilton Human Engineering the Small Business Computer Barry Mathis Cost Effective Electronics for the Small Business Computer Gerald L Meyer and V DeLloy Forbes HP 250 Input Output System Dennis L Peery HP 250 BASIC A Friendly Interactive Powerful System Lan guage Dennis L Peery Low Cost Data Base Management Michael V Hetrick Applications Software for the Small Business Computer Scott W Y Wang and Loyd V Nelson Capacitance and Conductance Deep Level Transient Spectro scopy Using HP IB Instruments and a Desktop Computer Leo nard Forbes and Ulrich Kaempf May 1979 A Precision Programmable Pulse Generator Werner H ttemann Lutz Kristen and Peter Aue Extending Possibilities in Desktop Computing Sandy L Chumbley Processor Enhancements Expand Memory Damon Ujvarosy and Dyke T Shaffer Designing to Meet Electromagnetic Interference Requirements John C Becker Assembly Programming Capability in a Desktop Computer Robert M Hallissy June 1979 Business Computer for the 1980s George R Clark The Integrated Display System and Terminal Access Method Eric P L Ha and James R Groff Reducing the Cost of Program Development Frederick W Clegg Managing Data HP 300 Files and Dat
29. a Bases Phillip N Taylor Alan T Par and James R Groff An Easy to Use Report Generation Language Tu Ting Cheng and Wendy Peikes HP 300 Business BASIC May Y Kovalick Innovative Package Design Enhances HP 300 Effectiveness David A Horine July 1979 Cost Effective Hardware for a Compact Integrated Business Com puter Arndt B Bergh and Kenyon C Y Mei Computer Input Output System Based on the HP Interface Bus W Gordon Matheson Small Low Cost 12 Megabyte Fixed Disc Drive Richard L Smith An Innovative Programming and Operating Console Alfred F Knoll and Norman D Marschke AMIGO 300 A Friendly Operating System Ralph L Carpenter Configuring and Launching the AMIGO 300 System Donald M Wise and James C McCullough Multiple Output Switching Power Supply for Computer Appli cations Dilip A Amin and Thane Kriegel August 1979 New Performance Standards in Microwave Spectrum Analysis Siegfried H Linkwitz Broadband Input Mixers for a Microwave Spectrum Analyzer John C Lamy and Frank David Synthesized Microwave Local Oscillator with Continuous Sweep Capability Larry R Martin Kenneth L Lange and Stephen T Sparks A Digital Pattern Generator for Functional Testing of Bus Oriented Digital Systems G nter Riebesell Ulrich H bner and Bernd Moravek An HP IB Extender for Distributed Instrument Systems David H Guest September 1979 SOS Technology Yields Low Cost HP 3000 Computer
30. a bytes In general the format for program data strings consists of sets of alphanumeric character sequences One or more alpha characters identify a parameter and the numeric field identifies the parameter selection or value Specific code assignments however are unique to each device For example the following message programs a voltmeter to measure a dc voltage on the 10 volt range upon receipt of an internal trigger and then output the measured quantity de function 10 volt range immediate internal trigger output mode 3 execute program The voltmeter s response to the command might be OLDC 12002E 03CRLF Here the OLDC provides summary status data indicating that the measurement is a dc voltage but the value in this case 12 002 volts expressed in exponential notation is beyond the normal 10 volt range specified and is therefore flagged as an overload condition This message can be divided into three fields header alpha only numeric value representing the measured quantity and separator or ending to the message the carriage return line feed The overall structure of the format is defined but individual product implementations select the particular message elements appropriate for that product Standardization efforts are now in progress at national and inter national levels to provide a set of guidelines for the preferred syntax and formats applicable to products with ANSI IEEE 488 capability It is anticipated t
31. ackson A Synthesized Signal Source with Function Generator Capabil ities Dan D Danielson and Stanley E Froseth Viewpoints Paul Baird on Electronic Equipment Reliability February 1979 A High Quality Digital X Y Plotter Designed for Reliability Flexi bility and Low Cost John A Fenoglio Bessie W C Chin and Terry R Cobb Linear Step Motor Design Provides High Plotter Performance at Low Cost Lung Wen Tsai and Robert L Ciardella Developing a Low Cost Electrostatic Chart Hold Table Alec J Babiarz Simple Efficient Electronics for a Low Cost X Y Plotter William G Royce and Peter Chu A Closed Loop System for Smoothing and Matching Step Motor Responses Philip P Maiorca and Norman H MacNeil Multi Frequency LCR Meters Test Components under Realistic Conditions Kohichi Maeda and Yoh Narimatsu March 1979 Circuit Board Testing Cost Effective Production Test and Trouble shooting Peter S Stone and John F McDermid Rapid Digital Fault Isolation with rAsrRAcE William A Groves Software Simulator Speeds Digital Board Test Generation Ken neth P Parker Virtual Memory for TESTAD and FASTRACK Douglas L Baskins Analog In Circuit Component Measurements Problems and Solu tions David T Crook User Oriented Software for an Automatic Circuit Board Tester Ed O Schlotzhauer Testing the Tester Roland H Burger John J Ketchum Scott E Woodward and James M Brown Hardware Design of an Automatic Circuit Board
32. act is allowed Advancing Paper Cutting Paper Opening the Blades between the blades and there is no rubbing action to dull the blades Repeated and lengthy life tests have failed to damage or wear out the blades which are self sharpening Transmission Design The cutting action and the advance action use the same prime mover a step motor The motor drives only a gear train directly with all other operations controlled by pas sive clutches The gear train provides power takeoff points with correct torque capacity for each function of the trans mission The paper is advanced by forward rotation of the motor with torque transmitted through a dog coupling see Fig 5 This coupling is essentially a high backlash coupling When paper is to be cut the motor reverses direction The paper is held in position by the ratchet as the motor disen gages from the sprocket drive shaft Simultaneously an overrunning clutch couples the motor to the four bar link age to cut the paper When the upper shear blade completes its stroke the motor again reverses direction Initially al though the motor is driving forward the paper does not advance because the high backlash dog coupling is not engaged The shear blade reopens driven upwards by a spring The motor still effectively controls the shear open ing through the overrunning clutch When the shear blade is returned to its original full open position the overrun ning clutch begins slippi
33. ading the HP IB byte from the USART universal synchronous asynchronous receiveritransmitter is accompanied by a go no go flag The link command cir cuits then ensure that acknowledgment of correct receipt of the data is sent in the minimum amount of time to the opposite 12050A This is done by sending a short burst of pulses at 10 Mbits second that can be distinguished from normal data by special circuitry Acknowledgment of HP IB data on a byte by byte basis in this way minimizes the overhead involved in data buffering and helps to ensure real time responses to asynchronous messages By consciously restricting supplemental circuitry to the critical timing sequences a secondary design goal was achieved This was to minimize package size and power consumption Thus overall cost is minimized through re duced power supply complexity while reliability is in creased The calculated mean time between failures MTBF for the 12050A is greater than 30 000 hours of operation an important factor in manufacturing applica tions At the same time the emitted radiation of the 12050A is extremely low making it a good fit for HP IB systems concerned with measuring electromagnetic interference EMI In actual tests using a 12050A and a 2240A Mea surementand Control Processor the combination of thetwo instruments was at least 10 dB below the VDE level B requirements for emissions from industrial instrumenta tion System Level Capabilities The f
34. age during each measurement is dis played along with the current or capacitance data The details of the staircase voltage used mainly for I V a SCENE dded the d to main measurement val oldest value is subtraci tain a running average characterization are shown in Fig 3b The voltage can be stepped in increments selectable with 0 01V or 0 1V resolu tion depending on the voltage range The hold time is selected to allow time forthe device or material under test to settle at the new voltage The measurement time is deter mined by the selected integration time for the picoammeter Low Leakage Accessories Great care must be exercised when connecting a picoammeter to a device for very low current measure ments because leakage currents can degrade the measure ment significantly A set of cables Fig 4 is provided with the 4140A to minimize inaccuracies due to leakage The cable for the current input is a low noise triaxial cable that helps minimize leakage currents Also available is an acces sory test fixture Fig 5 that provides both electrostatic and light shielding for the device under test An option equips the 4140A to work with the HP Interface Bus so that all front panel controls can be programmed remotely With this option measurement data can be sent to acontroller for processing and then displayed in a variety of formats an especially useful capability in a manufacturing environment where ra
35. age variable capaci tances Cy and Cy actually the gate capacitances of a dual junction FET and the center tapped secondary of transformer T1 form a bridge driven by a 500 kHz 20 mV signal The bridge is balanced when there is no input to the HILO terminals but when a dc voltage Vin appears at the input one capacitance increases and the other decreases so the bridge becomes unbalanced An ac voltage V2 then appears at the input to amplifier A1 This voltage is amplified in 1 reconverted to de by the synchronous detector and smoothed in integrator A2 Total gain from input to output Vj to Vo is more than 100 dB Note that there is no dc path in the input circuit This plus careful layout of the circuits surrounding the FETs achieves input bias currents of typically less than 3 FA and output Detector Fig 9 The input amplifier used in the 4140A has a high dc input irn pedance since there is no dc path in the input circuit In the absence of an input the bndge formed by transformer T1 and capacitances C and C is balanced An input voltage unbalances C and differentially and an ac voltage V2 then appears at the input 10 amplifier A1 Vo DECEMBER 1979 HEWLETT PACKARD JOURNAL 13 Copr 1949 1998 Hewlett Packard Co 10 x 1075 A 30 minutes offsets of less than 10 4 V C at room temperatures The feedback through range resistor Rg however makes the circuit input impedance appear
36. al drive deck de sign and the new automatic paper ad vance for the 9872 7220 and 7221 Plotters He s listed as inventor in five patents on X Y recorder mechanical design Dick was born in Glendale California He received an AA degree trom John Muir College in 1952 then V spent two years in the U S Army Corps 1 of Engineers before joining HP in 1954 He s married has four children ranging Iw in age from 9 to 21 lives in California and is half owner of a Commanche 250 aircraft which flies whenever he can Randy A Coverstone Randy Coverstone was responsible for transmission design and the paper ten sioning and loading schemes on the 98725 72215 72205 Plotters He is cur rently doing servo design work on anew plotter In 1975 Randy graduated trom the University of Evansville in Indiana with his BSME degree and in 1978 received an MSME degree and the de gree of Mechanical Engineer from Mas sachusetts Institute of Technology He joined HP in 1978 A native of Goshen Indiana Randy now lives with his wife in il Mira Mesa an area San Diego BEES California He is currently building an electronic music synthesizer and his hobbies include cars stereo components and building doll house furniture Majid Azmoon Maj Azmoon was project leader for de velopment of the 98725 72215 72205 four color plotter paper advance mod els An HP employee since 1973 he previously contribut
37. am even fewer computers begin responding to real time situa tions in less than one millisecond So speeds of 20 000 bytes per second and above are quite adequate for most of today s instrumentation systems and the ease of developmental changes offered by a microprocessor design was a signifi cant advantage Determining the Critical Timing Paths There is a complete spectrum of trade offs between the design that performs the maximum number of logic deci sions using a microprocessor and the design that com pletely eliminates the microprocessor and implements all the logic in hardware alone The key to a successful microprocessor based design that maximizes throughput is to implement in hardware those logic decisions that fall into the critical timing paths Fiber optic transmitterireceiver pair used with up to 100 metres of duplex cable to transmit and receive data and control signals PHI Processor to HP IB chip Pro vides the interface between MC and USART universal synchronous asynchronous receiveritransmitter the HP IB It is provides the inter capable of all face between the HP IB controller and the fiber and talkerilistener optic components functions It transmits and receives data asynchronously at IMBUS Micro Computer Chip is a 16 bit micro processor oper ated at a 5 MHz clock rate It is op 2K x 16 bits of ROM contains all of the firmware timized for etfi logic n
38. am Kahan is professor of mathema tics and computer science at the Uni versity of California at Berkeley An HP consultant since 1974 he has helped develop increasingly accurate arithme tic and elementary functions for the HP 27 67 97 32E and 34C Calcula tors financial functions for the HP 92 and 3BE C and other functions for the HP 32E and including and sovve or the 240 A native of Toronto 1m Canada he received his and PhD 4 7 degrees in mathematics and computer M science from the University of Toronto in i 1954 and 1958 then taught those sub jects at Toronto for ten years before moving to Berkeley A member of the American Mathematical Society the Association for Computing Machinery and the Society for Industrial and Applied Mathematics he has authored several papers and served as a consultant to several companies He is married has two teenage sons and lives in Ber keley Copr 1949 1998 Hewlett Packard Co Viewpoints Don Loughry Standard 488 and the HP Interface Bus Frequent reference has been made in these pages to the HP Interface Bus HP IB as Hewlett Packard s implementation of IEEE Standard 488 Digital Interface for Programmable Instrumenta tion Since inception of IEEE 488 in 1975 Hewlett Packard has striven to make HP s implementation a proper implementation of IEEE 488 In each case this represents a vali
39. ator with controllable slope 8566A July 1979 rive Winchester type HP 300 7910K June 1979 Display integrated HP 300 July 1979 Display integrated HP 300 Sept 1979 Displays X Y selectively blanked 1741A 002 E Sept 1979 Electromagnetic interference 3000 Series 33 suppression computer May 1979 design 9835A Jan 1979 Emitter function logic EFL Dec 1979 Equation solver handheld calculator HP 34C Dec 1979 Extender HP Interface Bus fiber optic 12050A Aug 1979 Extender HP Interface Bus telephone 37201A F Mar 1974 FASTRACE DTSi70 Mar 1979 Fault isolation in analog circuit boards 3060A Mar 1979 Fault isolation in digital circuit boards 1015170 Dec 1979 Fiber optic HP IB link 12050A Nov 1979 FM discriminator charge count 8901A Aug 1979 discriminator controllable slope B566A Nov 1979 Frequency measurements 8901A Jan 1979 Frequency measurements to 5314A 5315A B 100 MHz Nov 1979 Frequency modulation measurements B901A Jan 1979 Function generator synthesizer 3325A 0 to 21 MHz G July 1979 General I O channel 31262 Aug 1979 Generator logic pattern 8170A Copr 1949 1998 Hewlett Packard Co Dec Aug Oct June Feb Feb Oct Aug Sept Apr Oct Aug Nov Oct Jan Sept Oct Sept Apr Sept Aug Dec Jan Nov Keb Dec Sept Jan Nov July Aug Sept 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 1979 197
40. ctioning equation solvers The foregoing example in which roundoff so contaminated the first formula chosen for f x that the desired root was obliterated is not an isolated example Since the SOLVE key cannot infer intended values of f x from incorrectly calculated values it deserves no blame for roots that are wrong because of roundoff Getting roots right takes care fully designed programs on carefully designed calculators Equations with Several Roots The more numerous the roots the greater is the risk that some will escape detection Worse any roots that cluster closely will usually defy at tempts at accurate resolution For instance the double root in Fig 3c ought to be x In 4 1 386294361 instead of 1 386277368 but roundoff in the 10th decimal causes the calculated f x to vanish throughout 1 386272233 x 1 386316488 thereby obscuring the last half of the double root s digits Triple roots tend to lose 2 3 of the digits car ried quadruple roots 3 4 and so on All these troubles can be attacked by finding where the first few derivatives f x etc vanish but nobody knows how to guarantee victory in all cases What Have We Learned The reader will recognize first how little the pathologies illustrated above have to do with the specifics of the SOLVE key and second how nearly certain is the user of so powerful a key to stumble into pathologies sooner or later however rarely While the SOLVE key enhance
41. d A key objective for the development of the 12050A was to use existing hardware and technologies with an emphasis on HP fiber optic transmitter receiver pairs and SOS silicon on sapphire components These parts provide the high speed and low power consumption that allow the 12050A to achieve real time operation without overly com plex design In this way development emphasis could be concentrated on how to make the interface truly behave like a standard HP IB cable instead of wasting efforts on a broad range of hardware trade offs Centering the design approach around a high speed SOS microprocessor see Fig 4 provides a great deal of flexibil ity but at the same time limits the speed of the link The design center definition of real time however must rec ognize the capabilities of today s computers and instrumen tation Few instruments are capable of approaching the one megabyte per second theoretical rate of the HP IB and Remote Instrumentation Local Instrumentation Fig 3 The fiber optic link makes it easy to duplicate a group of HP IB instruments at several sites using a single computer atonesite many production test stations are in this category Copr 1949 1998 Hewlett Packard Co A Ready to Use Fiber Optic Link for Data Communications by Delon C Hanson During this past year there has been a significant growth in interest in adapting fiber optic data links to a broad spectrum of appl
42. d subset as not every device needs to use all the 488 capabilities However the HP IB is more significantly more than just the appropriate set of IEEE 488 options The IEEE and now ANSI 488 Standard referred to elsewhere as the GPIB defines the mechanical electrical and functional aspects of an interface in terms that are independent of devices or systems To start with HP products that have the HP IB capability use the complete mechanical and electrical specifications of 488 plus appropriate functional capabilities selected from the standard e g basic talker listener serial poll and service request capabilities parallel poll and device trigger capabilities etc A complete product interface however embraces additional opera tional characteristics at both the machine interface and human operator levels Consequently most HP products incorporate user oriented features that may be related to but are beyond the normal content of an interface standard For example in recogni tion of the need to facilitate user interaction with a device most HP instruments have front panel layouts and nomenclature that pro vide rapid identification of how those instruments are pro grammed over the HP IB The nomenclature for a spectrum analyzer s front panel controls to select center frequency for in stance highlights the C and the F to indicate that CF is the mnemonic for programming that control In the same vein systems t
43. e link s function Adaptable Coding The requirement for transmission down to zero hertz with arbitrary data format cannot be implemented in fiber optics as simply as in wire links where the use of opposite polarity pulses can establish a zero average dc level photons do not have a negative state Con sequently an internally generated code called pulse bipolar with refresh was developed The bipolar code is a translation from a two level electrical signal to three level optical signal Fig 1 A mid level luminance flux is established as the average dc level For a link specified to transmit data pulses with a minimum width of 100 ns each positive going data transition such as the leading edge of a data pulse generates a positive 60 ns optical pulse maximum luminance and each Electrical Input Signal Optical Line Code 4 Fig 1 negative going data transition such as a pulse s trailing edge gen erates a negative 60 ns pulse no luminance Whenever the time between data transitions exceeds about 5 us a refresh pulse of the same polarity as the previous pulse is generated and is repeated every 5 us until a data pulse of the opposite polarity occurs The refresh pulses provide transparent signal continuity in dependent of the data stream for maintaining ALC automatic level control action at the receiver and for use in monitoring the status of the link Transmitter Module The transmitter uses
44. ecessary to cient operations perform self test performed directly and ail operations 1 0 registers Fig 4 The fiber optic link has a single printed circuit board with a combination of advanced technologies PACKARD JOURNAL DECEMBER 1978 simplified picture of the logic flow controlling the movement of data across the 12050A Fiber Optic Link is illustrated in Fig 5 There are four key operations Read HP IB Data Format and Transmit the Data Receive and Verify the Data Write HP IB Data Remote 12050A Local 12050A Receive Form Checksum Mark Byte As Retransmit Transmit Optic Bytes Acknowledge Fig 5 Simplified flow of HP IB data in the 12050A Receipt of each byte is acknowledged by a handshake to the opposite 12050A Copr 1949 1998 Hewlett Packard Co The microprocessor adds a fifth component because the very process of determining which operation to perform takes time Each of these operations has special hardware logic to minimize the overall time necessary for the entire operation For example the receive and verify function is supplemented with two special circuits shown in Fig 6 The error control circuit verifies correct receipt of the HP IB byte Each byte is accompanied by a second byte composed of two bits of control information and six bits of checksum information This checksum is compared in hardware so that the process of re
45. ed to the 9872A Plotter and the 72454 Plotter Printer is named as inventor on a patent relat ing to the 7245A He earned his BSME degree in 1969 at California Polytechnic University and received his MSME de gree two years later alt the University of Southern California Born in Tehran Iran Maj now lives in Poway California with his wife and two year old son In his spare time he enjoys racquetball woodworking and restoring old Ford Mustangs SPECIFICATIONS Automatic Paper Advance for HP Models 9872S 72215 and 7220S Graphic Plotters PAGE ADVANCE 10 12 seconds typical PAGE TO PAGE ADVANCE ERROR 0 4 mm 0016 in non cumulative PAGE REGISTRATION 2 mm 0 080 in PAGE CUTTING ACCURACY al 50 relative humidity 1 2 mm 0 080 in PRICES IN U S A 98725 6500 72215 6750 72205 6750 MANUFACTURING DIVISION SAN DIEGO DIVISION 16399 West Bernardo Drive San Diego California 92127 U S A Road Palo Alto Packard Bulk Rate U S Postage Paid Hewlett Packard Company CHANGE OF ADDRESS Copr 1949 1998 Hewlett Packard Co
46. elligence of the host plotter Thus the electrical components of the paper advance consist solely of a motor identical to the resident motors of the host plotter small printed circuit board containing a relay for the motor driv ing circuitry and the paper advance front panel switches and paper sensor switches The modules take advantage of the power supply mi croprocessor input output capability and motor drive cir cuitry of the plotter by simply switching power from the plotter Y axis to the paper drive motor At completion of the paper advance the relay returns power to the plotter Y axis motor The plotter reinitializes its position and is restored to the exact configuration that existed immediately before the advance command The only changes required of the plotter to implement this are the addition of firmware code to accommodate the paper advance sequence and the cabling to and from the modules Ratchet Slip Clutch Fig 3 Page length is held constant and cumulative error eliminated by a combination of a ratchet and a spring loaded slip clutch Copr 1949 1998 Hewlett Packard Co Fig 4 Paper shear mechanism works like scissors Controlling Advance Accuracy An important aspect of the paper advance is the control of cumulative error If preprinted forms are to be used the advance length must not accumulate error if the grid form registration is to be maintained over a complete roll of pape
47. est or lowest point on a parabola that passes through the three points SOLVE then uses 6 and B as two guesses from which to resume the secant iteration At all times 8 and f 8 serve as a record of the smallest f x encountered so far But the parabola provides no panacea Roughly what it does provide is that if f x has a relatively shallow minimum in the neighborhood of 8 and 5 the calculator will usually look elsewhere for the desired root If f x has a relatively deep minimum the calculator will usually re member it until either a root is found or SOLVE abandons the search The search will be abandoned only when f 8 has not decreased despite three consecutive parabolic fits or when accidentally Then the calculator will display ERROR 6 with B in the X register f A in the Z register and yor in the Y register Thus instead of the desired root SOLVE supplies information that helps its user decide what to do next This decision might be to resume the search where it left off to redirect the search elsewhere to declare that f x is negligi ble so x is a root to transform 0 into another equation easier to solve or to conclude that f x never vanishes When invoked from a running program SOLVE does something more useful than stop with ERROR 6 in the dis play it skips the next instruction in the program The cal x 4 2 1x107 2x107 3x107 culator s user is presumed to have provided some
48. f its keys is labeled SOLVE by William M Kahan UILT INTO HEWLETT PACKARD S new handheld B ulator the HP 34C is an automatic numerical equation solver It is invoked by pressing the SOLVE key see Fig 1 For an illustration of how it finds a root x of an equation f x 0 take the function f x e with constants C and Equations f x 0 involving functions like this one have to be solved in connection with certain transistor circuits black body radiation and stability margins of delay differential equations If the equation f x 0 has real root x three steps will find it Step 1 Program f x into the calculator under say label A see Fig 2 Step 2 Enter one or two guesses at the desired root first guess ENTER second guess if any Any x will do as a guess provided f x is defined at that value of x but the closer a guess falls to a de sired root the sooner that root will be found Press SOLVE A and wait a little while to see what turns up Figs 3a 3d show what turns up for a typical assortment of Step 3 constants C and and first guesses When a root is found it is displayed But is it correct When no root exists or when SOLVE can t find one ERROR 6 is displayed But how does the calculator know when to abandon its search Why does it not search forever And if it fails to find a root what should be done next These questions and some others are addressed in the sections t
49. hat follow What does SOLVE Do and When Does It Work Neither SOLVE nor any other numerical equation solver can understand the program that defines f x Instead equa tion solvers blindly execute that program repeatedly Suc cessive arguments x supplied to the f x program by SOLVE are successive guesses at the desired root starting with the user s guess es If all goes well successive guesses will get closer to the desired root until ideally f x 0 at the last guess x which must then be the root SOLVE is distin guished from other equation solvers by its guessing strategy a relatively simple procedure that will surely find a root provided one exists in an astonishingly wide range of circumstances The three simplest circumstances are ones that predominate in practice 1 f x is strictly monotonic regardless of initial guesses or 2 lt is strictly convex regardless of initial guesses or 3 Initial guesses x and y straddle an odd number of roots i e and f y have opposite signs regardless of the shape of the graph of f In these cases SOLVE always finds a root of f x 0 if a root exists About as often as not SOLVE must be declared to have found a root even though f x never vanishes For example take the function Copr 1949 1998 Hewlett Packard Co PRGMIII RUN Switch to Program Mode e Clear Program Memory x Is in the X Register e LST x Get x Back E c
50. hat balloting will be initiated on an IEEE Recommended Practice within a few months Revisions to the Standard Revisions to the 488 standard itself were completed and published in November 1978 Since its inception as a pub lished document in April 1975 the 488 Standard has been read and interpreted by many engineers 14 000 copies distributed prior to the 1978 revision and as a result a number of comments were received concerning the clarity of certain clauses For example in one clause it was possible to misinterpret just when the END message could be sent In addition a few clauses needed to be reworded to reflect the onward march of technology e g the wide use of Schottky drivers mandates the use of 0 5 the low state output voltage Thus a revision of the standard was called for and completed in 1978 The predominant changes and additions are clarifications editorial changes that have no impact on technical matters see the IEEE Standard 488 1978 Foreword for a complete revision list However in several instances technically related issues were ad dressed with due consideration for backward compatibility During the revision period one additional problem area was discovered Under certain take control synchronously TCS conditions it was possible for an idle device to misinterpret a data byte DAB as an improper message This condition is a minor DECEMBER 1979 HEWLETT PACKARD JOURNA
51. hat make use of the HP IB interface concepts are provided with software to facilitate user interaction with the system For example typical HP IB systems that use a computer are supplied with general purpose drivers that take care of addressing sending commands effecting end of record and responding to service requests with minimal if any operator in teraction The user need be concerned therefore only with appli cation data In addition the documentation contains verification routines and program examples a typical application program is frequently provided to introduce the new user to the system and its capabilities These added capabilities both hardware and software related are all part of the HP IB concept that goes beyond the 488 standard Thus HP IB may be thought of as 488 plus added user features that facilitate user understanding convenience and effi ciency in interacting with HP IB products Further details on these added features will be discussed in a forthcoming Journal article Ed Codes and Formats For some time HP has made use of generalized formats for device oriented messages such as those needed for sending pro gram data to a device and returning measurement results back to the controller The overall structure of these messages is specified in a device and system independent manner Each device then uses the generalized format by supplying or interpreting device specific dat
52. have to solve find the roots of equations of a certain type The problem can be stated simply as follows Given a formula that asks for a number and returns another number what number do you put in to make zero come out It s not a simple problem It often requires a trial and error solution guess at the root compute the result and if it isn t zero adjust your guess and try again Computers are good at this but it takes an expert to use one properly There are many pitfalls Now you can have the computer and the expert in the palm of your hand in the form of the SOLVE key on the HP 34C Calculator see page 20 You still have to know what you re doing but SOLVE automatically avoids many of the pitfalls Picoammeters measure very tiny currents like those that run over the surfaces of printed circuit boards or leak through transistor switches that are turned off Because current isa result of an applied voltage a voltage source is often needed when such currents are being measured Model 4140A Picoammeter page 10 is a very stable instrument that has built in voltage sources for generating bias step and ramp voltages It measures capaci tances too and is HP IB compatible of course And on page 29 is an article about a new mechanism that automatically changes the paper on HP four color plotters so the operator doesn t have to hang around all the time n December is our annual index issue The 1979 index is on the center four pages of this
53. hich f x took opposite signs thereby forcing successive guesses to converge to place where f vanishes or reverses sign That constraint is accomplished by modifying equation 2 slightly to bend the gt x t x 5 a b Y B Fig 5 Examples of how the secant iteration can cycle end lessly through the values a B y amp 1 a B y 2 y 6 3 5 4 6 aB and so forth Why Is Equation Solving Provably Impossible The merely Difficult we do immediately the Impossible will take ightly longer Old British naval maxim What makes equation solving merely difficult is the proper calcula tion of f x when the equation f x 0 has to be solved Sometimes the calculated values of f x can simultaneously be correct and yet utterly misleading For example let g x x 2 x 5 this is the function whose calculated values change sign but never vanish Next let the constant c be the calculated value of 9 10 3 this amounts to c 107 on an HP handheld calculator but another calculator may get Some other positive value Finally let f x 1 2 exp g x c The graph of 1 crosses the x axis despite the fact that the correctly rounded value calculated for f x is always 1 None of the arguments x for which f x differs significantly from 1 can be keyed into the cal culator so it has no way to discover that f x vanishes twice very near 10 3 namely at x 10 3 c Vin 2 3
54. iber optic link like any other HP IB device is as signed its own address and can communicate with the computer Four powerful system level requests from the computer to the 12050A are used to determine the general status of the link automatically Fig 7 Self test S causes execution of a series of routines contained in the ROM of each individual unit These routines exercise off line all of the control logic and circuitry used during normal opera tion A failure in any of these tests is indicated by a pattern in the front panel lights and indicates that the link cannot operate This test can also be manually initiated via the reset switch on the 12050A rear panel Link test L examines the integrity of the complete two pair link by initiating the transfer of all possible eight bit ASCII combinations from the local to the remote end The same patterns are then transferred back from the remote end to the local During the test all checksum errors are counted and the local 12050A can be interrogated to determine the results Extended link test E performs the same function as link test 256 times and the total error counts can be checked as in the link test Counting of checksum errors is not restricted to the self tests At any convenient time during normal operation Link Monitor IFC REN Special Handling Read Only Memory ROM Processor HP IB Interface PHI HP IB Univ Synchrono Receiver Tran
55. ications ranging from local data communications to long distance telephone communications This heightened interest results from the advan tages that optical fibers have over metallic conductors for transmit ting information The advantages depend on the application but include the following Immunity from electromagnetic interference No electromagnetic emission Freedom from ground loops Smaller cable size and weight Higher bandwidth Longer link length without repeaters Potentially lower cost in volume production Interest within Hewlett Packard in exploring the potential of fiber optics led to establishment of a program several years ago the corporate research laboratories that focused on the requirements for local data communications between computers terminals and in struments Since practical fiber optic components for these applica tions did not exist at the time system analysis was initiated to specify the functional features of a suitable link and the optimum balance of performance parameters for individual link components A basic requirement was that the fiber optic data link must behave like a TTL gate as far as signal inputs and outputs are concerned The user would thus not need any special optical expertise This implies that the transmit receive modules must accommodate Arbitrary data formats Data rates from dc to a specified maximum Operation from a single 5V supply Monitoring of th
56. icularly in view of the increased interest in both data communications and remote instrumentation Publication of the IEC 625 1 Standard should further benefit manufacturers and users alike Today products manufactured by more than 185 companies in at least 14 different countries use the capabilities of these standards it is possible to interconnect de vices using the 24 pin connectors with those using the 25 connector via a simple adapter cable one per system Progress in Components The ANSI IEEE 488 interface complements the widespread use of microprocessors in terms of such factors as data path width and ability to handle asynchronous data transfers Further within the last year several semiconductor firms introduced LSI chips to facilitate the implementation of IEEE 488 designs These chips which contain all but the controller function should enable ex peditious incorporation of the int cost and performance effective manner HP has used some of these chips to implement the HP IB ir face in additional products in a several designs and some internally designed LSI chips in others Today and the Future When IEEE Standard 488 was first published HP was already offering 30 products with HP IB capability Today that number has grown to 150 HP products spanning the spectrum from electronic measurement and stimulus instruments to medical and analytical equipment from small desktop controllers to full scale
57. id convergence but for two reasons the theory hardly ever matters First the theory shows how strongly the se cant formula equation 1 improves good estimates of a root without explaining how to find them even though the search for these estimates generally consumes far more time than their improvement Second after good estimates have been found the secant iteration usually improves them so quickly that after half a dozen iterations or so the tiny calculated values of f x fall into the realm of rounding error noise Subsequent applications of equation 1 are con founded by relatively inaccurate values f a and f 8 that Copr 1949 1998 Hewlett Packard Co Fig 4 Given guesses a and B with corresponding function values and the secant iteration produces a new guess y by the formula y produce a spurious value for the quotient f 8 f 8 fla Forthese reasons the secant iteration is capable of dithering interminably or until the calculator s battery runs down Figs 5a 5b show examples where the secant iteration cycles endlessly through estimates B 5 a B y 5 Therefore the secant iteration must be amended before it serve the SOLVE key satisfactoril SOLVE cannot dither as shown in Fig 5a because having discovered two samples of f x with opposite signs it con strains each successive new guess to lie strictly between every two previous guesses at w
58. ights The fourth system level request down link D is a useful tool in certain applications where it is advantageous lem porarily to cease communications with remote HP IB de vices The simplest case is when HP IB data transfers faster than 20 000 bytes per second are desired at the local end of a link Normally the data transfer can occur only at the rate of the slowest device on the bus which in this case is the local 12050A When the down link request is given before the higher speed transfer the local 12050A completely ignores the transaction Another use of the down link command is illustrated in Fig 3 Where a group of instruments is identical to another the two groups can be accessed alternately via two fiber optic links by alternately setting the links off line group even down to the individual HP IB addresse Compatibility Testing The extensive use of HP IB systems throughout HP pro vided an opportunity to characterize the performance of instrumentation systems interfaced via the 12050A Fiber Optic Link and to ensure operation with a broad spectrum of applications Tests were run at seven different HP divi sions using demonstration programs production test pro grams lab development programs and programs specifi cally developed for verifying HP IB compatibility of other ts Over fifty different HP IB compatible devices were used in one or more of the systems exercised The instrumen performance of
59. ing or listening to classical music MT ABBREVIATED HP Model 4140A pA Meter DC Voltage Source MEASUREMENT FUNCTIONS I V and C V 1 Independent picoammeter and programmable voltage source IV KV characteristic measurements C V Quasi static characteristic measurement VOLTAGE SOURCES and Vg Function VOLTAGE SWEEP Auto or manual pause DISPLAYS CURRENT 31 digits with 2 digt annunciator VOLTAGE 3 digits Current Measurements RANGE 1 000 x 107210 1 000 10 2A full scale in 11 ranges auto or manual ranging 90 overrange ACCURACY INTEGRATION TIME Accuracy 1 Time ms Range eotrdg counts Shon Medum Long 1072 09 rom 20 s 32 40 217 10 VOLTAGE BURDEN 10 V at full scale ZERO OFFSET RANGE 0 to 100 10 5A TRIGGER Output Data INT EXT and HOLD MAN SPECIFICATIONS Capacitance Voltage C V Measurement RANGE 0 0 pF to 1900 pF auto ranging ZERO OFFSET RANGE 0 to 100 pF C RANGE 0 0 to 199 9 Capacitance change in device under test percent of the set value of the oxide capacitance Cox 100 s displayed as a DC Voltage Sources RANGES V ANO Vg fo 100 0 V MAXIMUM CURRENT 10 mA both VOLTAGE SWEEP Auto and manual pause up down step in manual pause mode Sweep abort enables reset PARAMETER SETTING RANGES START STOP V 0 to 10 00V 0 01V steps 0 to 100 0V 01 steps STEP
60. itive going The positive comparator output sets an RS flip flop and the negative comparator resets it regenerating the original two level data waveform The receiver circuits are designed into an integrated circuit that is housed in a module similar to that used for the transmitter Connectors and Cable Precision single fiber connectors with a small diameter were de veloped for inclusion as integral parts of the module and as cable 10 cable interconnects Also developed was a rugged fiber optic cable specifically optimized for local data communications It has a 100 um diameter fused silica core with a glass cladding that is protected by a thin silicone coating between the fiber and a buffer jacket The buffer jacket is surrounded by strength members and a polyurethane outer jacket to provide rugged single fiber per channel cable assembly Acknowledgments Paul Greene Tom Hornak and Bill Brown of HP s Solid State Research Laboratory were instrumental in the conceptual and pro totype phases of this development program Roland Haitz George Girot Steven Garvey Lee Rhodes Joe Bagley and Hans Sorensen of HP s Optoelectronics Division made substantial contributions dur ing final development Personnel at HP s Santa Clara Division coop erated on the development of and processing for the receiver inte grated circuit and many others unfortunately too many to be men tioned here made significant contributions to the development progr
61. l purpose Apr 1979 Conductance DLTS Feb 1979 Control system linear step motor 7225 1979 Controller desktop 9835A 16 HEWLETT PACKARD JOURNAL DECEMBER 1979 Brubaker Interactive Modulation Analyzer Control Paul J Lingane Special Signal Source Tests Modulation Analyzer Leslie E Brubaker December 1979 High Speed Fiber Optic Link Provides Reliable Real Time HP IB Extension Robert B Grady A Ready to Use Fiber Optic Link for Data Communications Delon C Hanson A Picoammeter with Built in Synchronized Voltage Sources Hitoshi Noguchi Annual Index Personal Calculator Has Key to Solve Any Equation f x 0 William Kahan Viewpoints Don Loughry on ANSI IEEE Standard 488 and the HP Interface Bus Four Color Plotters Enhanced for Unattended Operation Majid Azmoon Randy A Coverstone and Richard M Kemplin Jan 1979 Counter chip multiple register Jan 1979 Counter universal 100 MHz low cost 5314A Jan 1979 Counter universal 100 MHz reciprocal 5315 Dec 1979 Current measurements picoampere 4140A D Apr 1979 Data base management HP 250 June 1979 Data base management HP 300 Oct 1979 Data communications analyzer 1640A Apr 1979 Deep level transient spectroscopy DLTS May 1979 Desktop computer 9835A Feb 1979 Digital LCR meters multifrequency 4274A 75A Aug 1979 Digital pattern generator 8170A Feb 1979 Digital X Y plotter 7225 Nov 1979 Discriminator charge count B8901A Aug 1979 iscrimin
62. lems at the expense of increased cost complexity and noise These problems are circumvented in the paper drive sys tem by tensioning the paper across the writing table see Fig 2 With suitable tension maintained uniformly across the web the required paper flatness is obtained over the desired range of environmental conditions The electro static hold down is automatically disabled whenever roll paper is tensioned across the table The required tension is provided by a pair of brakes in the supply module The primary brake is mounted to the paper hub which is keyed to the supply roll This brake is supplemented by another brake acting on the circumfer ence of the paper roll which conveniently doubles as a 30 HEWLETT PACKARD JOURNAL DECEMBER 1979 paper supply indicator The combined braking effect pro duces a tension that is virtually constant over the diameter range of the supply roll The paper is driven by sprockets in the drive module The paper is perforated at the final sheet width and sprocket holes are punched outside the perforations The sprocket drive provides positive registration for accurate advance lengths and lateral guidance This scheme is also compati ble with both English and metric sheet sizes paper is supplied with appropriate perforation spacing for both sizes Simple Electronics The electronics complement of the paper advance mod ules is minimal Full advantage has been taken of the power and int
63. lyzer 4 to 1300 MHz 8754A Root finder handheld calculator HP 34G RPG business computer HP 300 5 Sales analysis HP 250 Semiconductor process development DLTS system Serial data analyzer 1640A ping container HP 300 Signal generator 11715A Signal source programmable synthesizer 3325A function generator 0 to 21 MHz n on sapphire processor HP 300 Silicon on sapphire processor HP 300 SOLVE equation solver HP 34C SOS processor HP 3000 Series 33 Simulator for digital board testing DTS 70 TESTAID Source 11715A Source logic pattern 8170A Source pulses programmable 8160A Spectrum analyzer 100 Hz to 22 GHz B566A Step motors linear 7225A Synthesis frequency fractional N 3325 Synthesizer function generator 3325A 0 to 21 MHz System 35 9800 Series 9835A Systems HP IB extender for 37201A Systems HP IB extender for 12050A T TESTAID program generator for digital DTS 70 board testing Time interval measurements 5314A 5315A H Triggered X Y oscilloscope displays 1741A 002 Troubleshooting circuit boards DTS 70 3060A automatically Troubleshooting computer HP 3000 Series 33 remote Troubleshooting microprocessor training 5036A Universal counter 100 MHz low cost 314A Universal counter 100 MHz reciprocal 5315A B v VCO measurements 8901A Virtual memory operating system HP 300 Virtual memory for digital DTS 70 board tester x X Y displays selectively blanked 1741 A 00
64. minicom puter controllers from simple cable assemblies to complete in strumentation and computing systems Worldwide the number of products introduced with IEEE 488 capability is doubling every two years or so There are now about 0 products with IEEE 488 capability or equivalent i e HP IB IEEE Bus IEC 625 GPIB Plus Bus etc The int rface is used most frequently as the primary or only interface port for bench instru ments measurement and stimulus devices which account for about 56 of the bus compatible products Controllers account for another 11 storage and display for 8 and complete systems of all types for about 12 The balance covers a wide spectrum cable assemblies quad transceivers LSI chips and couplers to convert BCD interfaces to IEEE 488 and to convert IEEE 488 bus signals toa serialized version to extend the maximum bus distance beyond 20 metres see the article on page 3 of this issue and also D Guest An HP IB Extender for Distributed Instrument Systems Hewlett Packard Journal August 1979 There are even products that use IEE bers It is impossible to predict exactly what the future holds but the 488 concepts for such devices as environmental test cham nd automatic screw driver equipment current use of these interface concepts both within HP and on a national and international level testifies that the IEEE 488 and its IEC and HP IB counterparts serve highly useful purpose today
65. ng again the dog again engages the sprocket drive and the paper begins advancing once again This simple mechanism allows all three kinematic func tions of the transmission advancing paper opening the shear blades and closing them to be controlled by a single motor with attendant cost savings Paper Stacking Once the completed plot has been cut to length the page passes between rollers located between the blades and the outer wall Driven continuously by a belt these rollers give the sheet a final push into the stacking tray They also isolate the advance system from obstructions or interfer ence occurring outside the machine thereby preventing jamming of the drive system and consequent loss of data Acknowledgments Theauthors would like to acknowledge the contributions made by others to this product Larry Hennessee worked on the electronics hardware and firmware and Don Hiler did the product design Thanks also go to Jurgen Przyllas and Tom Young for production and manufacturing engineering support and Rick Mayes for his product marketing con tributions Fig 5 Dog coupling makes it possible for a single transmission to contro all paper advance and paper cutting functions At Rest DECEMBER 1979 HEWLETT PACKARD JOURNAL 31 Copr 1949 1998 Hewlett Packard Co Richard M Kemplin Dick Kemplin has been a draftsman and product designer with HP for 23 years He helped develop the pen changer mechanic
66. ngle phase 86V to 127V 172V to 254V FREQUENCY 48 Hz to 66 Hz POWER CONSUMPTION 15W OPERATING TEMPERATURE 0 o 55 C HUMIDITY 10 to 95 relative humidity non condensing at 40 C PHYSICAL DIMENSIONS HEIGHT 9 cm 3 5 in WIDTH 21 cm 8 4 DEPTH 44 om 17 4 in WEIGHT 2 75 kg 6 Ib 1 oz 39200 Series Fiber Optic Cable OPERATING TEMPERATURE 0 to 70 C STORAGE TEMPERATURE 40 to 85 C RELATIVE HUMIDITY 95 at 70 C MAXIMUM TENSILE FORCE ON CABLE 30 kg 66 Ib per channel MAXIMUM TENSILE FORCE ON CONNECTORICABLE 5 kg 1 1b MINIMUM BEND RADIUS 7 mm 0 3 in FLEXING 50000 cycles 180 bending at minimum bend radius CRUSH LOAD 20 kg 44 00 CABLE CONSTRUCTION Simplex one channel and duplex two channel cable connec torized at each end Each channel consists of fused silica slightly graded index glass lad fiber 140 um diameter surrounded by silicone coating buffer jacket and tensile strength members Outer jacket is polyurethane The two channels of e duplex cable are connected by an easily separated zip cord structure which also provides channel identity by extruded ridge on one side WEIGHT 12 grams 0 43 az per metre simplex 24 grams 0 85 oz per metre duplex Ordering Information MP 12050A FIBER OPTIC HPIB LINK unit includes installation and Service Manual 12050 90001 Two 12050A units are required per remote application Each pair of 12050A units requires one or two af
67. nt fluctuations mA 1x10 to 21x10 amperes The 3 2 digit read out gives a resolution of 1 femtoampere 10715 on the most sensitive range A zero offset cancels leakage currents in the test leads or fixtures of up to 100x 10 15 amperes Measurement data is stabilized by digital averaging To accommodate changing values a moving average of the readings is kept with the oldest reading discarded when a new one is added Fig 2 The number of readings averaged integration time is selectable short medium long ac cording to the desired meter response or expected mea surement fluctuations These times are automatically ex tended on the more sensitive ranges and shortened on the higher ranges to maintain the fastest response consistent with the measurement noise Automatic Voltage Control Each of the two programmable voltage sources spans 100 V in two ranges 10 00V 100 0V and is capable of supplying up to 10 mA Individually selectable current limits of 107 107 or 1072 amperes protect sensitive devices The ramp voltage provided by one of the sources is used for measurements of capacitance based on the relationship farads qam dvidt For example if the ramp rate dV dt is 0 01 V s and the measured current is 1 234x 107 A Exi 2080079 0 01 P The details of the ramp are shown in Fig 3a The ramp slope is selectable from 1 mV s to 1 V s in 1 mV s steps The average ramp volt
68. of physical and chemical phenomena Many of these measurements also require adjustable voltage sources so current can be determined as a function of the applied voltage new Model 4140A pA Meter Dc Voltage Source was developed in response to these needs It includes a sensitive picoammeter and two voltage sources all managed by a microprocessor One of the voltage sources can be pro grammed to step through a range of values and to hold at each step while the current is measured The other voltage source provides a fixed bias for measurements on devices such as transistors where two bias voltages are required Previously measurements of this nature were made with manually controlled instruments consuming much time or with automatic test systems that cost at least three or four times as much as the 4140A in addition to requiring pro gramming expertise The 4140A can also be programmed to supply ramp voltage to the device under test for quasi static capac itance versus voltage measurements a technique that is especially applicable to measurements on MOS capacitors High Resolution with Stability The pA meter in the 4140A is a floating autoranging picoammeter that has full scale ranges from 1 pA to 10 8 cccg 005 c00 m etr 10 Heme 5 eggo 1 89000 68 agocce amp Copr 1949 1998 Hewlett Packard Co 9 10ms 50 Hz 8 3 ms 60 Hz Fig 2 Measureme
69. ons gh aesthetic appeal as well as clarity in wever if an original graph is photocopied The paper advance these much of the original impact is lost allows multiple original copies to be made easily preserv the impact for more information users Design Features Fig 1 shows a 98725 Plotter with paper advance The is designed to accommodate a 200 foot roll right hand module or supply side The paper advance of paper in the paper is fed across the platen and through the left module KARD JOURNAL 29 Copr 1949 1998 Hewlett Packard Co Fig 2 Paper drive system holds the paper flat against the platen by applying constant tension to the paper web which drives and cuts the paper and feeds the finished sheets into the paper tray Acontinuous roll paper supply instead of z fold provides the usera choice of plotting area and final sheet size with no risk of finding a fold or perforations within the plot area The built in shear blades and microprocessor can produce mixed page sizes with a single setup and either single sheet or continuous output all under front panel or pro gram control Paper Drive System The paper drive system is the most essential and critical part of the paper advance This system must accurately position the paper on the writing platen control paper flatness in the plotting area to prevent extraneous marks during pen up moves and maintain the paper posi
70. pid feedback is desirable Another option provides analog signals for driving an X Y recorder Examples of the measurements that can be made with the 4140A are shown in Fig 6 Fig 6a is a typical C V measure ment plotted by a Model 9872 Digital Plotter under con trol of a Model 9825 Desktop Computer that also controls the 4140A through the HP Interface Bus Fig 6b is an I V measurement Since the current varies over a wide range in this measurement the autoranging feature of the 4140A proves to be especially useful Fig 6c is a plot of an I V measurement in which both voltage sources are varied under program control Internal Details A simplified block diagram of Model 4140A is shown in Hewiett Packard s implementation of ANSIHEEE 488 1978 Fig 3 a Details of the ramp volt age The start and stop voltages hold time and ramp slope are selectable Themeasurementtime is determined vy the picoammeter 1 i 1 gt circuits b De ails of the staircase voltage DECEMBER 1979 HEWLETT PACKARD JOURNAL 11 Copr 1949 1998 Hewlett Packard Co Fig 5 Accessory test fixture provides electrostatic and light 1998 Hewlett Packard Co Copr 1949 Fig 7 A current to voltage converter at the input generates a voltage proportional to the measured current for proces sing by conventional digital voltmeter circuits in this case successive approximation A to D converter to achieve
71. plot after plot automatically under computer control In this Issue issue so you can remove it and file it elsewhere without affecting any of the articles Our cover subject is the new 12050A Fiber Optic HP IB Link The HP IB is Hewlett 4 Packard s version of an industry standard method for connecting instruments and computers to form a system If ordinary cables are used for the connections their lengths can t add up to more than 20 metres according to the standard In our August 1979 issue we fea tured a product that uses telephone lines to overcome this limitation and send HP IB informa tion around the world if need be The new fiber optic link doesn t send it quite that far 100 metres is the maximum distance now but it s much faster than telephone transmission Fiber optic cables the link part of the 12050A are those thin flexible strands that take in light at one end guide it this way and that and finally spit it out the other end having lost very little of it in the process You transmit information over them by varying the intensity of the light source Besides speed of transmission they provide electrical isolation and noise immunity The cables used by the 12050A are another HP product The present form of the HP IB is now about five years old and its use is still spreading On page 27 Don Loughry who helped bring it into being shares some of his thoughts on its past present and future Engineers and scientists often
72. program to cope with SOLVE s possible failure to find a root and then SOLVE skips into that program This program might calcu late new initial guesses and reinvoke SOLVE or it might conclude that no real root exists and act accordingly There fore SOLVE behaves in programs like a conditional branch if SOLVE finds a root it executes the next instruction which is most likely a GTO instruction that jumps over the program steps provided to cope with failure Therefore the HP 34C alone among handheld calculators can embed equation solving in programs that remain entirely automatic regard less of whether the equations in question have solutions Some Problem Areas Equation solving is a task beset by stubborn pathologies in its full generality the task is provably impossible see page 23 Even though equations that matter in practice may not fall into the Chasm of the Impossible yet they may teeter on the brink Rather than leave the user teetering too the HP 34C Owner s Handbook devotes two chapters to SOLVE one introductory and one more advanced The second chap ter discusses equation solving in general rather than the SOLVE key alone and supplies the kind of helpful advice rarely found in textbooks Here follow examples of things that users might need to know but are unlikely to have learned except from bitter experiences which the Hand book tries to forestall Hard versus Easy Equations The two equations f x 0 and
73. r This can be accomplished by having the preprinted forms registered accurately to the sprocket holes when they are printed and by accurately controlling the rotation of the sprocket drive shaft To minimize the advance error a ratchet is used in combi nation with a spring loaded slip clutch Fig 3 When the drum reaches the end of its advance which is a predeter mined number of revolutions it stops and is rotated in the opposite direction by the spring that pulls on the slip clutch This opposite rotation is limited when the pawl contacts the first available tooth of the ratchet This mechanism acts as a mechanical analog to digital converter to filter out advance length variations caused by gear backlash and motor switching inaccuracies The result is no variance in page length other than the tolerances built into theratchetand paper and no cumulative error whatsoever Paper Shear As the paper leaves the left side of the machine it passes between two stainless steel blades The lower blade is sta tionary while the upper blade is driven down by a four bar linkage driven by the transmission see Fig 4 The blades operate exactly as do ordinary scissors The upper blade is at an angle to the lower blade both in the vertical plane shear angle and in the horizontal plane interference angle The upper blade is pivoted and held against the lower blade with a spring This geometry in sures a long life for the cutter Only point cont
74. ration time was set to LONG solution to this problem often used in digital voltmelers is to use an autozero operation The autozero operation dis connects the input signal grounds the amplifier input and closes a negative feedback loop around the amplifier to a holding capacitor at the amplifier s inverting input If the amplifier has an offset at the instant the switching takes place the offset would start to charge the holding capacitor in the same direction as the offset but since the capacitor voltage is applied to the amplifier s inverting input the capacitor voltage tends to counteract the offset As a result the offset is reduced by a factor proportional to amplifier gain The feedback loop is then opened and the offset cor rection voltage is retained on the capacitor To keep offset drift at negligible levels an autozero opera lion should be performed at least once every 10 seconds Since ramps generated by the 4140A may last hundreds of seconds the ramp generator was designed to permit auto zeroing at 10 second intervals without creating any discon tinuities in the ramp As shown in 12 the autozero operation is performed on main amplifier A1 and the offset correction voltage is retained on holding capacitor Cy local integrator A2 within the main integrator loop dupli cates the ramp in response to the voltage that the main feedback loop places on holding capacitor Cy While the autozero operation is being performed
75. s exclusive use are just five memory registers for data and a handful of other bits Those five memory registers hold three sample argu ments B and y and two previously calculated sample values f a and f 8 while the user s f x program is calculat ing f x from the argument x y which it found in the stack How does SOLVE choose that argument y Suppose and both lie close to a root x of the equation f x 0 Then a secant straight line that cuts the graph of f at the points xa and x y 1 A must cut the x axis at a point x y 0 given by B 8 o FU IG a Provided the graph of f is smooth and provided is a simple root i e f z 0 f Z then as Fig 4 suggests y must approximate much more closely than do a and f In fact the new error y can be expressed as DECEMBER 1979 HEWLETT PACKARD JOURNAL 21 Copr 1949 1998 Hewlett Packard Co f x exp x x 2 f x exp x 4x 4 4 4 1800 16 00 14 00 1200 8 00 f x exp x 5 3 x exp x 20x 90 5 00 4 00 3 00 2 00 1 00 0 00 100 2 00 3 00 4 00 c L 1 10 00 6 00 2 00 200 6 00 10 00 9 Fig 3 Examples of soLve results for different values of C C and different first guesses for the root x in the program of Fig 2 a If the first guess is 99 the root x 0
76. s its user s powers it obliges its user to use it prudently or be misled And here is Hewlett Packard s dilemma The company cannot afford a massive effort to educate the public in nu 26 HEWLETT PACKARD JOURNAL DECEMBER 1979 merical analysis But without some such effort most poten tial purchasers will remain unaware of SOLVE s value to them And without more such effort many actual purchas ers may blame their calculator for troubles that are intrinsic in the problems they are trying to SOLVE To nearly minimize that required effort and its attendant risks SOLVE has been designed to be more robust more reliable and much easier to use than other equation solvers previ ously accepted widely by the computing industry Whether that effort is enough remains to be seen Meanwhile we enjoy the time SOLVE saves us when it works to our satisfac tion which is almost always Acknowledgments 1 am grateful for help received from Dennis Harms Stan Mintz Tony Ridolfo and Hank Schroeder Hank wrote the Handbook s chapters on SOLVE Tony found ways to im prove the SOLVE key s program while microcoding it Dennis contributed some improvements too both to the program and to this explanation of it but owe him most thanks for along with Stan supporting our efforts en thusiastically despite justifiable doubts Reference 1 D W Harms New Accuracy Making 22 Hewlett Packard Journal November 1976 William M Kahan Willi
77. smitter USART Error Control Microprocessor MCC Random Access Memory RAM Status Butter Front Panel Lights Data and Link Command Separator Optic Link Optic Receiver Link Command Transmitter Optic Transmitter Fig 6 Simplified 12050A block diagram LSI functions are supplemented by discrete logic to maximize speed DECEMBER 1979 HEWLETT PACKARD JOURNAL 7 Copr 1949 1998 Hewlett Packard Co DIAGNOSTIC REQUESTS S Execute self test at local and remote link units L Execute link test to verify correct operation of complete 12050A to 12050A link E Execute extended link test link test executed 256 times D Down the link Both local and remote 12050As are set off line and do not interfere with any transactions until irc message is received via local HP IB these local and remote checksum error counts can be read to ensure that no partial degradation of the link has occurred Each time the error counts are read they are reset to zero Besides monitoring integrity by counting checksum er rors the firmware attempts to report the cause of any ir recoverable error in the link For example when a link monitor error generated by the fiber optic receiver module whenever the received light level falls below the mir m acceptable level is detected by one of the 12050As it causes a continuous flashing pattern in the front panel l
78. st cases will ot affect system perlormance SERVICE REQUEST RESPONSE Remote device service request SRO asserted at local and of link typically within 100 jus of its occurrence ERROR DETECTION AND CORRECTION Detection of Yransmitted errors between 12050A units is done using a checksum byte comparison technique I an error is detected retransmission of the byte wil occur until it is correctly roceivod CONFIGURATION CAPACITY Each 12050A unit is treated as an HP IB device and is subject to HP IB cabling and configuration restrictions imposed by the interface standard CONNECTORS HP IB connector is Ihe standard IEEE 488 1978 24 pin female connector tor use with HP 10631A BIC D HP IB cables Fiber optic connectors are precision ferrule optical connectors for use with 39200 Series Fiber Optic Cables see Fiber Optic Cable specifications HP IB FUNCTION SUBSETS SUPPORTED SH1 75 TES L3 LE3 SA1 RL T PPO DC1 DT1 C1 C2 C3 C4 C27 Controller unctions parallel poll and pass control are not supported Refer to IEEE Std 488 1978 OVERALL SYSTEM COMPATIBILITY The HP 12050A Fiber Optic Link has been designed to allow HP IB devices to communicate with each other over long distances just they would locally using standard HP IB programming techniques and conventions Extensive testing has been performed using a wide variety of HP IB compatible instru ments to ensure such operation POWER REQUIREMENTS VOLTAGE ac si
79. t 1 as gt 0 But when that root x is calculated numerically for tiny values of p using the most straightforward program possible some thing awful happens as shown by the black graph in Fig 9 That serrated graph reflects the capricious way in which the calculated equation s left hand side changes sign once for p 10 at root x 1075 seven times for p 2 15 x 10710 at roots x 4 65 x 10799 0 233 0 682 0 698 0 964 1 163 and 1 181 All those roots are wrong the correct root is x 0 999999999 These aberrations caused by one rounding error the one committed when exp px is rounded to 10 significant digits Carrying more figures will not dispel the aberrations but merely move them elsewhere To solve x h px 0 correctly one must calculate h z accurately when z is tiny Here is the easiest way to do that if exp z rounds to 1 then set h z 1 otherwise set h z exp z 1 In exp z This reformulation succeeds on all recent HP handheld calculators because the LN key on these calculators retains its relative accuracy without de gradation for arguments close to 1 see reference 1 Con sequently In 2 conserves the rounding error in the last digit of exp z well enough for that error to cancel itself in the subsequent division thereby producing an ac curate h z and a trustworthy root x Generally wrong roots are attributable more often to wrong equations than to malfun
80. the link within 100 microseconds of its occurrence at the remote end Serial communications are performed at one megabit per second for data and protocol support and at ten megabits per second for special messages These specifica tions ensure that most HP IB systems perform just as they do when connected in strictly local configurations The 12050A detects any errors in transmission from one end of the link to the other and automatically retransmits the data until it is received correctly At a continuous rate of 1 Mbit second over 10 bits hour can be transmitted Most fiber optic parts have specified reliabilities in the range of 1 error in 10 transmissions Thus it is important that the 12050A perform automatic error correction even though the probability of any errors is very small since many con trol applications run twenty four hours a day The use of the 12050A Fiber Optic Link is illustrated in Fig 2 One unit is connected to the local computer s HP IB port and another is connected remotely to an instrumenta tion application No special programming is necessary to use the 12050A This is particularly important to many existing applications Fig 3 characterizes the typical use 4 HEWLETT PACKARD JOURNAL DECEMBER 1979 of an instrumentation cluster in a production environ ment and demonstrates the ease of duplicating the test set up while maintaining the advantages of single com puter control Established Technologies Use
81. tible with it makes the HP IB attractive to a broad user base which brings with it new problems and environments that challenge the IE Operating Lights Link integrity lights reflect re sponses to high priority messages Left light is nor on and others are off Self Test Error Code Lights Transmit Optic Link Connector Receive Optic Link Connector standard specification One trend is toward smarter devices capable of functions previously found in the domain of the computing controller control data processing storage and high speed communications Another trend is a grow ing need to distribute these devices to remote areas around a laboratory or industrial process separated by distances that exceed the cable length limitations of the IE standard A Fresh Look at the Interface The 12050A Fiber Optic HP IB link one unit shown in Fig 1 removes the necessity of locating HP IB instruments in relatively close proximity to a computer while main taining the real time characteristics necessary to many ap plications Fiber optics was selected as the transmission medium partly because the areas where the HP IB is in creasingly used present harsh electromagnetic noise envi roninents Since fiber optic transmission is via light it is LOCATION REMOTE iS lit when an internal Switch indicates unit is not conti gured to be con nected to com puter H
82. tion to prevent shifting while the plot is being produced The diffi culty of these tasks is increased by the range of environmen tal conditions imposed upon the system Reliable operation must be guaranteed over a broad range of temperatures and humidity to which paper is particularly sensitive as well as during vibration such as that created by the plotter dur ing operation Of these performance requirements the most difficult is maintaining paper flatness across the platen area In single sheet operation the paper is held in place by the electrostatic table of the plotter The sheets are placed and flattened by the operator This method is unsuitable in automatic unattended operation for several reasons First even after the electrostatic table is turned off a large force is required to shear the paper from the table Thus extremely high tractive forces or a mechanism to peel the paper from the table would be required Second without an operator a mechanism would be required to smooth out the wrinkles as the electrostatic table pulls down the paper Third at high humidity the effectiveness of the electrostatic table is diminished Although an operator can monitor this be havior and tape a single sheet to the platen if required this obviously presents reliability problems in unattended op eration if the electrostatic table is expected to hold the paper Replacing the electrostatic table with a vacuum table would overcome these prob
83. to quit it can t go on forever but it can go on for a long time e g when 1 They may require that you prescribe tolerance and then oblige you to accept as a root any estimate closer than that tolerance to some previous estimate even if both estimates are silly SOLVE will claim to have found a root x only when either f x 0 or lt 0 for some y differing from x only in their last 10th significant dec imal digit 4 They may claim that no root exists when they should admit that no root was found SOLVE will not abandon its search unless it stumbles into a local minimum of f namely an argument x for which f y f x 71 at all other usually at least nine sampled arguments y on both sides of x 5 They may deny to the program that calculates f x certain of the calculator s resources for instance begin with no label other than A do not use storage registers 0 through 8 do not use certain operations like CLR or SOLVE allows the f x program to use everything in the calculator except the SOLVE key Moreover SOLVE may be invoked from another program just likeany other key on the calculator and f x can use the HP 34C s powerful y key A lot of thought has gone into making SOLVE conform to Albert Einstein s dictum As simple as possible but no simpler How Does SOLVE Work The SOLVE key s microprogram uses very little of the HP 34C s resources Reserved for SOLVE
84. ugh SOLVE can now guaran lee convergence ultimately that might not be soon enough since ultimately we all lose patience Fortunately con vergence cannot be arbitrarily slow At most six and nor mally fewer iterations suffice to diminish either successive errors x or successive values f x by an order of magnitude and rarely are more than a dozen or two itera tions needed to achieve full ten significant digit accuracy So fierce is the bent secant iteration s urge to converge that it will converge to a pole where f x if no zero where f x 0 is available and this is just as well because poles and zeros cannot be distinguished by numerical means t ye Nog Fig 7 With a wild initia guess the rounded value of y may coincide with B This convinces some equation solvers that y is the root SOLVE perseveres until it locates the root 6 correctly 24 HEWLETT PACKARD JOURNAL DECEMBER 1979 4 00 4 3 00 2 00 1 00 H t 100 050 2 00 2 00 7990 1 4 00 5 00 f x exp 6x x 1 1 b w00 200 f x In 6x 100 050 Fig 8 These three equations all have the same roots but a is easy to solve b with a bad initial guess gets worse and equation c is defined only close to its roots alone see page 23 What does SOLVE do when all the values f x sampled so far have the same sign As long as successive samples I
85. with the main feed back loop open A2 continues ramp generation in response to the voltage held on Cjj Hence no discontinuities are introduced into the ramp The overall amplification provided by A1 and A2 in cas cade provides extremely high open loop gain minim any nonlinearity in the ramp Acknowledgments Yoshihisa Kameoka who was the project leader during the early stages was responsible for the pA section Keiki Kanafuji also contributed to the pA section design Susumu 14 HEWLETT PACKARD JOURNAL DECEMBER 1979 p Out Fig 12 Ramp generator under goes autozero operations for the main amplifier without disturbing the ramp in progress Local Integrator Copr 1949 1998 Hewlett Packard Co HEWLETT PACKARD JOURNAL Volume 30 January 1979 through December 1979 Hewlett Packard Company 1501 Page Mill Road Palo Alto California 84304 USA Hewlett Packard Central Mailing Department Van Heuven Goedhartiaan 121 1180 AM Amstelveen The Netherlands Yokogawa Hewiett Packard Ltd Suginarm ku Tokyo 168 Japan PART 1 Chronological Index January 1979 Low Cost Microprocessor Based 100 MHz Universal Counter Lewis W Masters Karl M Blankenship and Michael J Ward Lowest Cost HP Universal Counter Developed Using 1 51 and Manufacturing Innovations Michael D Wilson and David M George High Performance Bipolar LSI Counter Chip Using EFL and PL Circuits Bosco W Wong and William D J
86. z Feb 1979 LCR Meter 10 kHz 10 MHz Feb 1979 Microprocessor Lab Oct 1979 100 MHz Universal Counter Jan 1979 100 MHz Universal Counter Jan 1979 1979 May 1970 Guest David H Feb 1979 Ha Eric P L Jan 1979 Hallissy Robert M Mar 1979 Hamilton A Peter May 1078 Hanson Delon C 1979 Hotrick Michael V Sept 1979 Holl James H lan 1979 Horine David A Oct 1979 Howard P Guy Mar 1979 H bner Ulrich Nov 1979 H ttemann Werner Mar 1979 Jackson William D July a June 197 Feb 1979 Feb 1979 Kaempl Ulrich May 1979 Kahan William Feb 1979 Ketchum John lune 1979 Knoll Alfred P 198 Kohli Manmohan Feb Kovalick May Y Mar Kriegel Thane Kristen Lutz lam 1979 Aug 1978 Lamy John C Lange Kenneth L Lingane Paul J Linkwitz Siegfried Nov 1079 Sept 1979 Ox 1979 MacNeil Norman H Maeda Kohichi Maiorca Philip P Sept 1974 Marschke Norman D Feb 1979 Martin Larry R 1979 Masters Ls Mar 1974 Matheson Apr 1979 Mathis Barry Apr 1979 Matsui Yas lam 1978 McCullough James MeDermid John F Mei Kenyon C Y Meyer Gerald L jam 1979 2 Moravek Bernd 18 HEWLETT PACKARD JOURNAL DECEMBER 1979 ndex off James R Groves William A 7220S 7221S 7225 7910K 8160A 8170A 8566A 8754A 8901A 9835A B 98728 11715A 12050A 31262A 31264A 37201A 47804A S 63312F June Mar Aug June May Apr Dec Apr

Personal Calculator Has Key To Solve Any Equation

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