Model:-28CGeneral:Name:noneCode-Name:PaladinFamily:Clamshell?Logic:RPLFeatures:scientific, programmable, hyperbolics, complex,base w/arithmetic, matrix, vector, lists,solver (algebraic, program), symbolic math,plotting, graphics, etc., etc.Firsts:RPL, general units, graphing, complex numbers,symbolic math, symbolic integration,differentiationIntroduction:Date:1987-1-5Price:$235Discontinuation:Date:1988-1Price:$235Production-Run:?Display:Type:LCD, bit-mappedSize:4 line x 23 chars, 32 x 137 pixelsNumber-Formats:sign, 12 mantissa, ., exp sign, 2 expAnnunciators:Oa program is suspended---^shift key pressedaalphabetic keys active((.))busybatterybattery low(2\pi)radians modeprinterprinter data being sentData:User-Visible:Smallest:1E-499Largest:9.99999999999E499Signif.-Digits:12Internal:Smallest:1E-49999Largest:9.99999999999999E49999Signif.-Digits:15Data-Types-and-Sizes:?typeobjectsize (bytes)display as0real number10.51.23451complex number18.5(6.7,8.9)(6.7,\<)8.9)2string5 +length"XYZ" or$C 5 hello3real array7.5+8*elements[ 9 8 7 ]4complex array7.5+16*elements[ (1,2) (3,4) ]5list5+2.5*elements+{ "FIN" Name }  element storage6global name5 + lengthX7local name5 + lengthj8programas list\<< Z 4 * \>>9algebraicas list'A=B-3'10binary integer10.5# 1010The sizes are guesses.Memory:Named-Registers:noneFlags:1-30user flags31LAST enable32printer trace33auto CR34principal value35symbolic constants36numeric results37-42binary word size43-44base 0)decimal 1)binary 2)octal 3)hex45level 1 display is multiline46reserved47reserved48radix 0). 1),49-50display format 0)STD 1)SCI 2)FIX 3)ENG51beeper on52faster print53-56number of digits in display57underflow is error58overflow is error59infinite is error60trig mode 0)degrees 1)radians61there was negative underflow62there was positive underflow63there was overflow64there was infiniteRegister-Usage:EQcurrent equationPPARplotting parameters {(xmin,ymin)(xmax,ymax) indepvar resolution(xaxis,yaxis)}n1,n2,...integers created by ISOLs1,s2,...signs created by ISOL and QUAD\GSDATcurrent statistics data\GSPARstatistics parameters {indepcoldependcol intercept slope }Numbered-Registers:noneProgram-Steps:memoryProgram-Editing:replace or insertProgram-Display:alphaUser-RAM-Bytes:1621Total-RAM-Bytes:2048ROM-Bytes:64KMachine-State:flagsstackuser memorymodes: entry mode, lower case, LAST COMMAND,LAST UNDO, system timerPhysical:Technology-Used:CMOSProcessor:1LK7 Saturn CPU (1 MHz), two 1LP4 ROMs(64KB each) and two 1LP2 Centipede chipscontaining the LCD driver/RAM/IOregister/power supply sectionsChip-Count:5 (2 ROMs, CPU, 2 display)Power-Source:3 alkaline N cellsContinuous-Memory:yesExpansion-Ports:noneI/O-Ports:I/R output, beeperClock:auto power offLength:6 1/2 inWidth:open 7 1/2 inclosed 3 5/8 inHeight:open 1/2 inclosed  5/8 inWeight:226.8gTemperature-Range:Operating:0 to 45 deg CCharging:noneStorage:-20 to 65 deg CKeyboard:Switches:noneShift-Keys:maroon, maroon, aboveUser-Defined-Keys:6 menu keysKey-Arrangement::** ** ** ** ** **    ** ** ** ** ** **** ** ** ** ** **    ** ** ** ** ** **** ** ** ** ** **    ***** ** ** ** **** ** ** ** ** **    * *** *** *** ***** ** ** ** ** **    * *** *** *** ***** ** ** ** ** **    * *** *** *** ******** ** ** ** **    * *** *** *** ***Key-Labels-Base-Keyboard::LeftABCDEFGHIJKLMNOPQRSTUVWXYZ#{[(SPACE\<<=LC\GaRight[][][][][][]maroon<^v>TRIGSOLVUSERNEXTENTERCHSEEXDROP<-'789\:-STO456xEVAL123-ON0.=+(The ON key has a white lower label of ATTN.)Key-Labels-Maroon-Maroon-Above::LeftARRAYBINARYCOMPLXSTRINGLISTREALSTACKSTORE[]ALGEBRA[]PRINT|---- PROGRAM -----|CTRLBRANCHTEST[]CATALOGUNITS\<=\>=\->\GS\^o\Gm<>"}])NEWLINE\>>\=/?\GaLOCKRight (top row labels are in white)INSDEL^V<>[]MODELOGSSTATPLOTPREVEDITVIEW^VIEWvROLLSWAPVISITCOMMANDUNDOLAST1/xRCLPURGE\.Sd/dx^->NUMCONT%%CH\v/ 2OFFCLEAR\piCONVERTxProgrammable-Operations::!gamma" "identify string#identify binary number%compute percent%CHcompute percent change%Tcompute percent total'identify algebraic( )precedence; identify complex number*Hadjust plot height*Wadjust plot width+addition-subtraction->create local variable->ARRYcreate an array->HMSconvert to HH.MMSS->LISTcreate a list->NUMevaluate an object to a numeric value->STRcreate a string0-9, .enter digit1/xreciprocal<comparison test="equal" comparison test=="equality" comparison test>comparison testAampere unitaare unit (100 m^2)ABORTabort program executionABSabsolute valueACOSarc cosineACOSHhyperbolic arc cosineacreacre unitALOGcommon antilogarithmANDlogical / binary andAoAngstrom unitarcminarc minutes unitarcsarc seconds unitARGcompute polar angle of a coordinateARRY->separate arrayASINarc sineASINHhyperbolic arc sineASRarithmetic shift rightATANarc tangentATANHhyperbolic arc tangentatmatmosphere unitauastronomical unitAXESset axes intersectionsbbarn unitB->Rconvert binary to realbarbar unit (pressure)bblbarrel unitBEEPsound a beepBINselect binary modeBqBecquerel unit of activityBtuBritish Thermal Unitbubushel unitCCouloumb unitC->Rconvert complex to realcalcalorie unitcdCandela unitCEILnext larger integerCENTRidentify center of plot displayCFclear flagchainchain unitCHRconvert integer to characterCHSchange signCiCurie unitCLEARclears the stackCLLCDclear displayCLMFclear the system message flagCLUSRclear all variablesCL\GSclear statistics dataCNRMcompute column normalCOLCTcollect like termsCOL\GSspecifies dependant and independant statistics variablesCONconstant arrayCONJcompute complex conjugateCONVERTcompute unit conversionCORRcompute correlation coefficentCOScosineCOSHhyperbolic cosineCOVcompute covarianceCRprint a carriage-rightCROSScompute cross productctcarat unitcucup unitdday unitd/dxcompute derivativeD->Rconvert degrees to radiansDECspecify decimal modeDEGspecify degrees modeDEPTHsize of stackDETcompute determinantDISPdisplay object in line of displayDO ... UNTIL ... ENDdo loopDOTcompute dot productDRAWdraw plotDRAXdraw axesDROPdrop one objectDROP2drop two objectsDROPNdrop N objectsDRW\GSdraw a statistics scatter plotDUPduplicate objectDUP2duplicate two objectsDUPNduplicate N itemsdyndyn unitesymbolic constant 'e'EEXenter exponentELSEcontrol structure componentENDcontrol structure componentENGspecify ENG modeENTERenterergerg unitERRMlast error messageERRNlast error numbereVelectron volt unitEVALevaluate objectEXGETget a subexpressionEXPnatural exponentiationEXPANexpands algebraicEXPMnatural exponentiation - 1FFarad unitFACTfactorialfathfathom unitfbmboard foot unitfcfootcandle unitFC?is a flag clear?FC?Cis a flag clear? and clearFdyFaraday unitfermiFermi unitFIXspecify FIX display modeflamfootlambert unitFLOORnext smaller integerFOR ... NEXTfor loopFOR ... STEPfor loopFORMchange the form of an algebraicFPfractional partFS?is a flag set?FS?Cis a flag set? then clearftfoot unitftUSUS foot unitggram unitgastandard freefall acceleration constantgalUS gallon unitgalCCanadian gallon unitgalUKUK gallon unitGETget an element from a list, vector, or matrixGETIget an element from a list, vector, or matrix and incrementgfgram-force unitgradgrads unitgraingrains unitGyGray unit of radiationHHenry unithhour unitHALTsuspend executionHEXspecify hexadecimal modeHMS+hh.mmss additionHMS-hh.mmss subtractionHMS->convert to hh.mmsshphorsepower unitHzHertz unitisymbolic constantIDNidentity matrixIF ... THEN ... ELSE ... ENDif-statementIF ... THEN ... ENDif-statementIFERR ... THEN ... ELSE ... ENDerror trapIFERR ... THEN ... ENDerror trapIFTstack-based ifIFTEstack-based if, can be used in algebraicsIMreturn imaginary partininch unitINDEPspecify independent variable for plottinginH20inches of water unitinHginches of mercury unitINVreciprocalIPinteger partISOLisolate an equation variableJJoule unitKEYcheck for key pressKILLabort all suspended programskipkilopound of force unitknotknots unitkphkilometers per hour unitlliter unitlamlambert unitLASTreturn last argumentslbAvoirdupois pount unitlbfpound-force unitlbttroy pound unitLIST->separate listlmlumen unitLNnatural logarithmLNP1natural logarithm + 1LOGcommon logarithmLRcompute linear regressionlxlux unitlyrlight-year unitmmeter unitMANTreturn mantissaMAXlarger of two numberMAXRlargest real numberMAX\GSlargest statistics valueMEANcompute meanMEMcompute available memorymhomho unitmiinternational mile unitmilmil unitMINsmaller of two numbersminminutes unitMINRsmallest positive real numberMIN\GSsmallest statistics valuemiUSUS mile unitmmHgmillimeters of mercury unitMODmodulusmolmole unitmphmiles per hour unitNNewton unitNEGnegate an argumentNEXTcontrol structure componentnminautical mile unitNOTlogical or binary notNUMconvert character to a numberN\GSnumber of entries in summationOBGETextract object from an algebraicOBSUBsubstitutes object into an algebraicOCTspecify octal modeOFFoffohmOhm unitORlogical or binary orORDERspecify order of objects in a directoryOVERselect objectozounce unitozflUS fluid ounce unitoztTroy ounce unitozUKUK fluid ounce unitPPoise unit of viscosityP->Rconvert polar to rectangularPaPascal unitpcparsec unitpdlpoundal unit of forcephphot unit of illuminancePICKfetch objectPIXELturn pixel onpkpeck unitPMAXsets the upper-right plot coordinatePMINsets the lower-left plot coordinatePOSfind position of object in anotherPR1print level 1 objectPREDVpredict the dependant variablePRLCDprint screenPRMDprint and display modesPRSTprint stackPRSTCprint stack compactlyPRUSRprint a list of variables in the current directoryPRVARprint a variablepsipounts per square inch unitptpint unitPURGEdeletes one or more variablesPUTput an element to a list, vector, or matrixPUTIput an element to a list, vector, or matrix and incremntqtquart unitQUADsolve a quadratic polynomialRroentgen unitrradian unitR->Bconvert real to binaryR->Cconvert real to complexR->Dconvert radians to degreesR->Pconvert rectangular to polarRADspecify radians moderadrad unit of absorbed doseRANDcompute random numberRCEQrecalls the current equationRCLrecall valueRCLFrecall flagsRCL\GSrecall the current statistics matrixRCWSrecall binary word sizerdrod unitRDMredimension a matrixRDZset the random number seedREreturn real partremrem unitREPEATcontrol structure componentRESset the plot resolutionRLrotate leftRLBrotate left byteRNDround numberRNRMcompute row normal of a matrix (maximum of sums of absolutevalues of all elements of all rows)ROLLroll stackROLLDroll stack downROOTcompute numerical rootROTmove level 3 object to level 1RRrotate rightRRBrotate right byteRSDcompute residual to solution of system of linear equationsSSiemens unitssecond unitSAMEcomparison testsbStilb unit of luminanceSCIspecify scientific display modeSCL\GSautoscale the plot according to the statistics dataSCONJconjugate the contents of a variableSDEVcompute standard deviationSFset flagSHOWresolve all name referencesSIGNreturn the sign of a numberSINsineSINHhyperbolic sineSINVinvert the contents of a variableSIZEreturns the dimensions of an objectSLshift leftSLBshift left byteslugslug unitSNEGnegates the contents of a variableSQsquaresrsteradian unitSRshift rightSRBshift right byteStStoke unit of viscosityststere unit of volumeSTART ... NEXTloop with no index variableSTART ... STEPloop with no index variable, variable stepSTDspecify standard display modeSTEPcontrol structure componentSTEQstore into EQSTOstore into variableSTO*store with multiplication into variableSTO+store with addition into variableSTO-store with subtraction into variableSTO/store with division into variableSTOFset system flagsSTO\GSstore into \GSDATSTR->separate stringSTWSsets binary wordsizeSUBextracts portion of an objectSvSievert unit of dose equivalentSWAPexchange two objectsSYSEVALevaluates objectTTesla unittmetric ton unitTANtangentTANHhyperbolic tangentTAYLRcompute Taylor series approximationtbsptablespoon unitTHENcontrol structure componentTHEN ... ENDcontrol structure componentsthermtherm unittonshort ton unittonUKUK ton unittorrtorr unitTOTcompute statistics sumsTRNtransposetspteaspoon unitTYPEreturns type of an objectuunified atomic mass unitUNTILcontrol structure componentUPDIRmove up one level in pathUTPCupper-tail Chi-Square distributionUTPFupper-tail F-distributionUTPNupper-tail normal distrbutionUTPTupper-tail t-distributionVvolt unitVARcompute variancesWWatt unitWAITpause execution for time or keyWbWeber unitWHILE ... REPEAT ... ENDwhile statementxmultiplicationXORlogical or binary xorXPONreturn exponentx^2squareydyard unityryear unity^xpower[ ]identify array\.ddifferentiate\.Sintegrate\:-division\<< \>>identify program\<=comparison test\=/comparison test\>=comparison test\Gmmicron unit\GS+add to statistics\GS-add to statistics\pisymbolic constant\v/xsquare root\^odegrees units\^oCdegrees C units\^oFdegrees F units\^oKdegrees K units\^oRdegrees R units^power{ }identify listNon-Programmable-Operations::*1multiply by 1+1-1add and subtract 1+CMDturn on command saving+LASTturn on last arguments saving+MLturn on multi-line display+UNDturn on undo saving-()double negate and distribute->()distribute prefix-CMDturn off command saving-LASTturn off last arguments saving-MLturn off multi-line display-UNDturn off undo saving/1divide by 11/()double invert and distribute<move leftshift <move left all the way<-erase last character or object<-->commute arguments<-Aassociate left<-Ddistribute left<-Mmerge factors left<^v>toggle between cursor menu and last menu>move rightshift >move right all the wayA->associate rightAFadd fractionsALGEBRAbring up menuATTNabort execution; exit special environments; clear messagesBRANCHbring up menuCATALOGstart the command catalog applicationCMPLXbring up menuCOLCTcollect like termsCOMMANDrecover previous command lineCONTcontinueCTRLbring up menuD->distribute rightDELdelete next itemDEL->delete item to the rightshift DEL->delete all items to the end of the lineDINVdouble invertDNEGdouble negateE()replace power-of-power with power-productEDITedit object in level 1EXGETget a subexpressionEXPANexpand a subexpressionEXPR=return expression or equation valuesE^replace power-of-product with power-of-powerFETCHexits catalog or units environment with current itemGO->set matrix entry mode to left-to-rightGOvset matrix entry mode to top-to-bottomGRAPHinvokes scrolling modeINSswitches between insert and replace editingshift INSdelete all characters to the left of the cursorL()replace product-of-log with log-of-powerL*replace log-of-power with product-of-logLABELlabels axesLASTtoggle saving of last argumentsLCtoggle upper/lower caseLEFT=evaluate left side of current equationLEVELenter level number to stackLISTbring up menuLOGSbring up menuM->merge factors rightMODEbring up menuNEXTnext screen or menuOFFoffONturn onON + +adjust contrastON + -adjust contrastON + <continuous self-testON + DELcancels system halt or memory reset if pressed before ONis releasedON + ENTER + <-go into deep sleep.  due to a bug, this mode actually drawsMORE current than ordinary off...ON + INS + >clear all memoryON + vstart system testON + ^system halt: stops program execution, clears local variables,clears the stackPLOTbring up menuPREVprevious screen or menuPRINTbring up menuQUITexit special applicationsRDX.set radix to .RDX,set radix to ,REALbring up menuRT=evaluate the right side of the current equationSCANadvance automatically thorugh special applicationSOLVbring up menuSOLVRbring up SOLVE menuSSTsingle stepSTACKbring up menuSTATbring up menuSTOPstop advancing automatically thorugh special applicationSTOREbring up menuSTRINGbring up menuTESTbring up menuTRACtoggle printer trace modeTRIGbring up menuUNDOrecover previous stackUNITSstart the units applicationUSEdisplays usageUSERbring up menuvmove downshift vmove down all the wayVIEWvmove display down one lineVIEW^move display up one lineVISITedits an object named in the command line[<-]move FORM cursor left[->]move FORM cursor right\Gatoggles alpha mode^move upshift ^move up all the way^1raise to power 1Menus::ALGEBRA:COLCTEXPANSIZEFORMOBSUBEXSUBTAYLRISOLQUADSHOWOBGETEXGETFORM:COLCTEXPANLEVELEXGET[<-][->]<--><-AA->->()<-DD-><-MM->DNEG-()DINV1/()*1/1^1+1-1L*L()E^E()AFARRAY:->ARRYARRY->PUTGETPUTIGETISIZERDMTRNCONIDNRSDCROSSDOTDETABSRNRMCNRMR->CC->RREIMCONJNEGBINARY:DECHEXOCTBINSTWSRCWSRLRRRLBRRBR->BB->RSLSRSLBSRBASRBRANCH:IFIFERRTHENELSEENDSTARTFORNEXTSTEPIFTIFTEDOUNTIENDWHILREPEAENDCATALOG:(catalog mode)NEXTPREVSCANUSEFETCHQUITCMPLX:R->CC->RREIMCONJSIGNR->PP->RABSNEGARGCTRL:SSTHALTABORTKILLWAITKEYBEEPCLLCDDISPCLMFERRNERRMLIST:->LISTLIST->PUTGETPUTIGETISUBSIZELOGS:LOGALOGLNEXPLNP1EXPMSINHASINHCOSHACOSHTANHATANHMODE:STDFIXSCIENGDEGRAD+CMD-CMD+LAST-LAST+UND-UND+ML-MLRDX.RDX,PRMDPLOT:STEQRCEQPMINPMAXINDEPDRAWPPARRESAXESCENTR*W*HSTO\GSRCL\GSCOL\GSSCL\GSDRW\GSCLLCDDISPPIXELDRAXCLMFPRLCDPRINT:PR1PRSTPRVARPRLCDTRACENORMPRSTCPRUSRPRMDCRREAL:NEGFACTRANDRDZMAXRMINRABSSIGNMANTXPONSOLVE:STEQRCEQSOLVRISOLQUADSHOWROOTSOLVR:list of solver variablesLEFT=RT= or EXPR=STACK:DUPOVERDUP2DROP2ROTLIST->ROLLDPICKDUPNDROPNDEPTH->LISTSTAT:\GS+\GS-N\GSCL\GSSTO\GSRCL\GSTOTMEANSDEVVARMAX\GSMIN\GSCOL\GSCORRCOVLRPREDVUTPCUTPFUTPNUTPTSTORE:STO+STO-STO*STO/SNEGSINVSCONJSTRING:->STRSTR->CHRNUMPOSDISPSUBSIZETEST:SFCFFS?FC?FS?CFC?CANDORXORNOTSAME==STOFRCLFTYPETRIG:SINASINCOSACOSTANATANP->RR->PR->CC->RARG->HMSHMS->HMS+HMS-D->RR->DUNITS:(units mode)NEXTPREVSCANFETCHQUITUSER:ORDERCLUSRMEMuser variablesBugs/ROM-Versions::You can obtain the version number by #A SYSEVAL (the only supportedSYSEVAL.)1BBfirst version1CCsecond version, late 1987The batteries were somewhat loose in the compartment.  This led toexcess corrosion and Memory Losts.1BB Bugs:- Turn a unit on and keep the ON key pressed for a moment.  Nowpress SHIFT.  There is a 50% chance that the unit will turn off.- Using the Solver with a program that does not return an object tothe stack.  Sometimes a system object will be placed there.- Trying to delete an empty row with shift INS while editing a commandline can lead to strange results and possibly a Memory Lost.- Dividing a 64 bit number with its top bit set can give wrong answers.- Otherwise equal binary integers with different word sizes do notnecessarily compare equal.  Try:#1 DUP 50 STWS 'A' STO 'A ENTER ==- If flags 57 or 58 are set the Solver might give an underflow oroverflow error while working to a solution.- The Solver can also give incorrect Sign Reversal messages.- User-defined units that are multiples of degrees Farenheight orCelsius give incorrect results.- The unit "yr" has been defined as 365 days instead of the correct365.242 days.  As "lyr" is defined in terms of this unit, it, too isincorrect.- RND does not work correctly in FIX mode (try "0 FIX .7 RND": you get0 instead of 1, unless you have flag 51 or 52 set!).  If you don'twant to set one of these flags, use ->STR STR-> to round the number.Actually, this demonstrates another problem.  Do:0 FIX MAXR ->NUMand you get 1.E500.  Now, ->STR gives "1.E500" then STR-> gives SyntaxError.- String comparisons produce incorrect results if the strings do notdiffer in their initial letter: "AA" "AB" < gives 0.- EDIT and VISIT can give unexpected results if you attempt to EEX orCHS an already-existing number.  Use "-" and "E" or delete and reenterthe number.- Memory can be corrupted by incorrect usages of the derivative function.- Merging left with the divide sign can give incorrect results.- Rounding of numbers in complex and matrix operations is sometimesslightly different than that of the same pure real numbers.- When the origin is not on the screen, plot tick marks are relativeto the screen instead of the origin.- The Out of Memory condition does not clear typeahead: you mayunexpectedly delete variables or programs.- The Solver does not always clear all internal flags.  Do:Memory Lost0 1/X(gives "Infinite result" and sets flag)DROP\<< A DROP 1 \>> STEQSolve for A without an initial guess.  You will get a System Halt.- Non-real results can cause the Solver to store a system object asthe variable's value.- Some special characters are not displayed on the menu line properly:characterdisplays as&e|Z~\\.x`\:-_proportionalityo]  (140 decimal)- (Not really a bug) Turning a string into a name, where the stringrefers to a name that already exists, will always hang due toinifinite evaluation recursion.Notes::This machine brought the functionality : memory ratio to heights neverbefore dreamed.HP28C: Hardware I/O basics document at:http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/articles.cgi?read=313As with the -45A, you can access an internal counter and turn it intoa clock.  Here is a set of programs to do this (written by JakeSchwartz and published in Datafile V6N4, June 1987):HEX 64 STWS\<< #123E SYSEVAL 8192 / \>> 'TIME' STO\<< HMS\-> 3600 * TIME B\->R - 'TD' STO \>> 'CS' STO\<< 4 FIX DO TIME B\->R TD + 3600 / 24 MOD \->HMS1 DISP UNTIL KEY END DROP \>> 'CLOCK' STOInstructions:- Enter the current time in HH.MMSS format.- Press USER CS to set the clock.- Press USER CLOCK to show the time.  It continues until you press a key.