Model:-28S, differences from -28CGeneral:Name:Advanced Scientific CalculatorCode-Name:OrlandoFeatures:?Firsts:graphics objects, directories foruser variablesIntroduction:Date:1988-1-4Price:$235Discontinuation:Date:1992-4-1Price:$195Production-Run:?Data:Data-Types-and-Sizes:?10binary integer10.5# 1010b  1-64 bits# 765o# 987d# FEDhMemory:Flags:46set by GETI and PUTI if they wrap47double spaced printingUser-RAM-Bytes:32,400Total-RAM-Bytes:32KROM-Bytes:128KPhysical:Processor:Lewis, 1 MHz (uses two, one has CPU disabled)Chip-Count:?Key-Labels-Maroon-Maroon-Above::Left[ARRAY][BINARY][COMPLX][STRING][LIST][REAL][STACK][STORE][MEMORY][ALGBRA][STAT][PRINT]|----- PROGRAM ------|[CONTRL][BRANCH][TEST][]CATALOGUNITS\<=\>=\->\GS\^o\Gm<>"}])NEWLINE\>>\=/?\GaLOCKRight (top row labels are in white)INSDEL^v<>[][MODE][LOGS][PLOT][CUSTOM]PREVEDITVIEW^VIEWvROLLSWAPVISITCOMMANDUNDOLAST1/xRCLPURGE\.Sd/dx^->NUMCONT%%CH\v/x 2OFFCLEAR\piCONVERTxProgrammable-Operations::->LCDput grob into LCDcspeed of light constantCOMBcombinationsCRDIRcreate directoryDGTIZactivate interactive plot modeHOMEmove to home directoryLCD->return LCD as a grobMENUselect a built-in menuPATHreturns current pathPERMcompute permutationsPOSless restrictive definitionVARSreturn list of variablesNon-Programmable-Operations::no +CMDno +LASTno +MLno +UNDno -CMDno -LASTno -MLno -UNDCMDenable/disable LAST CMD modeCOMPLXbring up menuCONTRLbring up menuCUSTOMcustom menuMENUStoggles shifted and unshifted actions of A-R keysMLtoggles multi-line display modeON + <- + ENTER, then S puts the machine into COMA mode (loses stackand halts timer, does not destroy memory)ON + Lprint screenON + NEXTstart keyboard testno ON + vno RDX.RDX,toggle radixno SCANno STOPUNDOtoggle undo saving\Gatoggles entry mode from immediate to alpha to algebraicshift \Ga toggles menu lockMenus::BINARY:DECHEXOCTBINSTWSRCWSRLRRRLBRRBR->BB->RSLSRSLBSRBASRANDORXORNOTLIST:->LISTLIST->PUTGETPUTIGETIPOSSUBSIZEMEMORY:MEMMENUORDERPATHHOMECRDIRVARSCLUSRMODE:STDFIXSCIENGDEGRADCMDUNDOLASTMLRDX,PRMDPLOT:STEQRCEQPMINPMAXINDEPDRAWPPARRESAXESCENTR*W*HSTO\GSRCL\GSCOL\GSSCL\GSDRW\GSCLLCDDGTIZPIXELDRAXCLMFPRLCDPRINT:PR1PRSTPRVARPRLCDCRTRACPRSTCPRUSRPRMDREAL:NEGFACTRANDRDZMAXRMINRABSSIGNMANTXPONIPFPFLOORCEILRNDMAXMINMOD%tSTAT:\GS+\GS-N\GSCL\GSSTO\GSRCL\GSTOTMEANSDEVVARMAX\GSMIN\GSCOL\GSCORRCOVLRPREDVUTPCUTPFUTPNUTPTCOMBPERMSTRING:->STRSTR->CHRNUM->LCDLCD->POSSUBSIZEDISPUSER:user variablesBugs/ROM-Versions::2BBfirst versionif you create a 256 x 256 matrix, you get memory lostNotes::Memory is now from an industry-standard chip instead of a -71B-typechip.  A "Power Lost" message has been added.  The battery compartmentis lined with foam.  The display has non-glare glass.  One-keyoperators are now entered into programs with spaces around them.  Thedefinitions of some units have been adjusted.  Program and variableprinting has been cleaned up and improved.HP28S: Hardware I/O basics document at:http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/articles.cgi?read=275A special version was produced celebrating 100 years of the AmericanMathematical Society.