------------------------------------------------------------------------ Proofs ========== The following is a list of some common proof techniques that are often extremely useful. 1 Proof by example: The author gives only the case n = 2 and suggests that it contains most of the ideas of the general proof. 2 Proof by intimidation: 'Trivial.' 3 Proof by vigorous handwaving: Works well in a classroom or seminar setting. 4 Proof by cumbersome notation: Best done with access to at least four alphabets and special symbols. 5 Proof by exhaustion: An issue or two of a journal devoted to your proof is useful. 6 Proof by omission: 'The reader may easily supply the details.' 'The other 253 cases are analogous.' '...' 7 Proof by obfuscation: A long plotless sequence of true and/or meaningless syntactically related statements. 8 Proof by wishful citation: The author cites the negation, converse, or generalization of a theorem from literature to support his claims. 9 Proof by funding: How could three different government agencies be wrong? 10 Proof by eminent authority: 'I saw Karp in the elevator and he said it was probably NP-complete.' 11 Proof by personal communication: 'Eight-dimensional colored cycle stripping is NP-complete [Karp, personal communication].' 12 Proof by reduction to the wrong problem: ' To see that infinite-dimensional colored cycle stripping is decidable, we reduce it to the halting problem.' 13 Proof by reference to inaccessible literature: The author cites a simple corollary of a theorem to be found in a privately circulated memoir of the Slovenian Philological Society, 1883. 14 Proof by importance: A large body of useful consequences all follow from the proposition in question. 15 Proof by accumulated evidence: Long and diligent search has not revealed a counterexample. 16 Proof by cosmology: The negation of the proposition is unimaginable or meaningless. Popular for proofs of the existence of God. 17 Proof by mutual reference: In reference A, Theorem 5 is said to follow from Theorem 3 in reference B, which is shown from Corollary 6.2 in reference C, which is an easy consequence of Theorem 5 in reference A. 18 Proof by metaproof: A method is given to construct the desired proof. The correctness of the method is proved by any of these techniques. 19 Proof by picture: A more convincing form of proof by example. Combines well with proof by omission. 20 Proof by vehement assertion: It is useful to have some kind of authority in relation to the audience. 21 Proof by ghost reference: Nothing even remotely resembling the cited theorem appears in the reference given. 22 Proof by forward reference: Reference is usually to a forthcoming paper of the author, which is often not as forthcoming as at first. 23 Proof by semantic shift: Some standard but inconvenient definitions are changed for the statement of the result. 24 Proof by appeal to intuition: Cloud-shaped drawings frequently help here. ------------------------------------------------------------------------ OP CODES PART I (A - E) ======================= (Contributed By Knappy 8350428 @ UWAVM) mnemonic meaning -------- ------- AAC Alter All Commands AAD Alter All Data AAO Add And Overflow AAR Alter At Random AB Add Backwards ABR Add Beyond Range ACC Advance CPU clock ACQT Advance Clock to Quitting Time ADB Another Damn Bug [UNIX] AEE Absolve engineering errors AFF Add Fudge Factor AFHB Align Fullword on Halfword Boundary AFP Abnormalized Floating Point AFVC Add Finagle's Variable Constant "the constant that must be added to make your data support your conclusions" AGB Add GarBage AI Add Improper AIB Attack Innocent Bystander AMM Answer My Mail AOI Annoy Operator Immediate AR Alter Reality ARNZ Add & Reset to Non-Zero ARZ Add & Reset to Zero AS Add Sideways AT Accumulate Trivia AWP Argue With Programmer AWTT Assemble With Tinker Toys BAC Branch to Alpha Centauri BAF Blow All Fuses BAH Branch And Hang BALC Branch And Link Cheeseburger BAW Bells And Whistles BB Branch on bug BBB Burn Baby Burn BBBB Byte Baudy Bit and Branch BBI Branch on Blinking Indicator BBL Branch on Burned-out Lamp BCB Burp and Clear Bytes BCBF Branch on Chip Box Full BCIL Branch Creating Infinite Loop BCR Backspace Card Reader BCU Be Cruel and Unusual BD Backspace Disk BDC Break Down and Cry BDM Branch and Disconnect Memory BDT Branch on Dumb Terminal BDT Burn Data Tree [next opcode after Decorate Data Tree BDU Branch on Dumb User BE Branch Everywhere [As in HHGttG's Infinite Improbability Computer" BF Belch Fire BH Branch and Hang BIRM Branch on Index Register Missing BLC Branch and Loop Continuous BLM Branch, Like, Maybe BLMWM Branch, Like, Maybe, Wow, Man BLR Branch and Lose Return BM Branch Maybe BMI Branch on Missing Index BNA Branch to Nonexistent Address BNR Branch for No Reason BOA Branch on Operator Absent BOD Branch on Operator Desperate BOHP Bribe Operator for Higher Priority BOP Boot OPerator BPD Branch on Programmer Debugging BPIM Bury Programmer In Manuals BPO Branch on Power Off BR Byte and Run BRA BRanch Anywhere BRA Branch to Random Address BRI BRanch Indefinitely BRO BRanch to Oblivion BRP Branch on Real Programmer BRT BRanch on Tuesdays BSC Burst Selector Channel BSM Branch and Scramble Memory BSO Branch on Sleepy Operator BSP BackSpace Printer BST Backspace & Stretch Tape BTD Byte The Dust BTJ Branch & Turn Japanese BTO Branch To Oblivion BW Branch on Whim BWABL Bells, Whistles And Blinking Lights BWOP BeWilder OPerator CAF Convert Ascii to Farsic CAI Corrupt Accounting Information CAIL Crash After I Leave CAT Confused And Tired [UNIX] CBA Compare & Branch Anyway CBNC Close, But No Cigar CBS Clobber BootStrap CC Call Calvary CC Crappy Control [UNIX] CCB Consult Crystal Ball CCCP Conceal Condition-Codes Permanently CCD Choke, Cough and Die CCD Clear Current Directory "this may really exist!" CCD Clear Core and Dump CCR Change Channels Random CCS Chinese Character Set CCWR Change Color of Write Ring CDR Complement Disk Randomly CFS Corrupt File Structure CG Convert to Garbage CH Create Havoc CHAPMR CHAse Pointers Around Machine Room CIB Change Important Byte CIMM Create Imaginary Memory Map CM Circulate memory CMD CPU Melt Down CMD Compare Meaningless Data CMI Clobber Monitor Immediately CML Compute Meaning of Life (42) CMP Create Memory Prosthesis CMS Click MicroSwitch CN Compare Nonsensically CNB Cause Nervous Breakdown COLB Crash for Operator's Lunch Break COMF COMe From COS Copy Object Code to Source File COWHU Come Out With your Hands Up CP%FKM CPU - Flakeout mode CP%WM CPU - Weird Mode CPB Create Program Bug CPR Compliment PRogrammer ("Aren't you cute!") CPSN Change Processor Serial Number CRASH Continue Running after Stop or Halt CRM Clear Random Memory CRN Convert to Roman Numerals [IBM Italy only] CRYPT reCuRsive encrYPt Tape mnemonic [UNIX] CS Crash System CSL Curse and Swear Loudly CSN Call Supervisor Names CSNIO Crash System on Next I/O CSU Call Self Unconditional " the ultimate in recursive programming" CSYS Crash SYStem CTDMR Change Tape Density, Mid Record CUC Cheat Until Caught CVFL Convert Floating to Logical CVFP ConVert FORTRAN to PASCAL CVG ConVert to Garbage CVU ConVert to Unary CWAH Create Woman And Hold CWDC Cut Wires and Drop Cores DA Develop Amnesia DAP De-select Active Peripheral DAUF Delete All Useless Files "would YOU trust a computer that far ???" DBL Desegregate Bus Lines DBR Debase Register DBZ Divide By Zero DC Degauss Core DC Divide and Conquer DCAD Dump Core And Die DCD Drop Cards Double DCGC Dump Confusing Garbage to Console DCI Disk Crash Immediate DCON Disable CONsole DCT Drop Cards Triple DCWPDGD Drink Coffee, Write Program, Debug, Get Drunk DD Destroy Disk DDC Daily During Calculations DDOA Drop Dead On Answer DDS Delaminate Disk Surface DEB Disk Eject Both DEC Decompile Executable Code DEI Disk Eject Immediate DEM Disk Eject Memory DES Disk Eject Swapped DHTPL Disk Head Three Point Landing DIA Develop Ineffective Address DIIL Disable Interrupts and enter Infinite Loop DIRFW Do It Right For Once DISC DISmount CPU DJ Deferred Jump DK Destroy Klingons DK%WMM Disk Unit - Washing Machine Mode DKP Disavow Knowledge of Programmer DLN Don't Look Now... DLP Drain Literal Pool DMPE Decide to Major in Physical Education DMPK Destroy Memory Protect Key DO Divide & Overflow DOC Drive Operator Crazy DPC Decrement Program Counter DPMI Declare Programmer Mentally Incompetent DPR Destroy Program DPS Disable Power Supply DRAF DRAw Flowchart DRI Disable Random Interrupt DRT Disconnect Random Terminal DS Deadlock System DSH Destroy Sector Header DSI Do Something Interesting DSPK Destroy Storage Protect Key DSR Detonate Status Register DSTD Do Something Totally Different DSUIT Do Something Utterly, Indescribably Terrible DT%FFP DecTape - unload and Flappa-FlaP DT%SHO DecTape - Spin Hubs Opposite DTC Destroy This Command DTI Do The Impossible DTRT Do The Right Thing DTVFL Destroy Third Variable From Left DU Dump User DUD Do Until Dead DVC Devaluate Computer DW Destroy Work DW Destroy World DWIM Do What I Mean DWIT Do What I'm Thinking DWL Define Word Length DWLZ Define Word Length Zero EBRS Emit Burnt Resistor Smell EC Eat card EC Eject Carriage ECI Execute Current Instruction ECL Early Care Lace ECO Electrocute Computer Operator ECP Erase Card Punch ED Eject Disk ED Execute Data [UNIX] EDD Eat Disk and Die EDIT Erase Data and Increment Time EDR Execute Destructive Read EDS Execute Data Segment EEP Erase Entire Program EFD Eject Floppy Disk EIAO Execute In Any Order EIO Erase I/O page EIOC Execute Invalid OpCode EIP Execute Programmer Immediately EJD%V EJect Disk with initial velocity V ELP Enter Loop Permanently EM Emulate 407 EM Evacuate Memory EMSL Entire Memory Shift Left EMT Electrocute Maintenance Technician EMW Emulate Matag washer ENF Emit Noxious Fumes ENH Execute No-op & Hang EO Execute Operator EOI Execute Operator Immediate EP Execute Programmer EPI Execute Programmer Immediate EPP Eject Printer Paper EPS Electrostatic Print and Smear EPS Execute Program Sideways EPT Erase Process Table EPT Erase Punched Tape ERI Execute Random Instruction ERIC Eject Random Integrated Circuit EROS Erase Read Only Storage "Sounds like an IBM special!" ESB Eject Selectric Ball "from IBM selectric typewriter terminals" ESL Exceed Speed of Light ETI Execute This Instruction [for recursive programs" ETM Emulate Turing Machine EVC Execute Verbal Commands EWD Execute Warp Drive EXX A real instruction on the Zilog Z-80 -Zilog is owned by EXX on" ------------------------------------------------------------------------ OP CODES PART II (F - Q) ======================== (Contributed By Knappy 8350428 @ UWAVM) mnemonic meaning -------- ------- FB Find Bugs FCJ Feed Card and Jam FDR Fill Disk Randomly FFF Form Feed Forever FLD FLing Disc FLI Flash Lights Impressively FM Forget Memory FMP Finish My Program FOPC [Set] False Out-of-paper Condition FPC Feed Paper Continuously FPT Fire Photon Torpedoes FRG Fill with Random Garbage FSM Fold, Spindle and Mutilate FSRA Forms Skip & Run Away GBB Go to Back of Bus GCAR Get Correct Answer Regardless GDP Grin Defiantly at Programmer GDR Grab Degree and Run GENT GENerate Thesis GESE Generate Exciting Sound Effects GEW{JO} Go to the End of the World {Jump Off} GID Generate Input Device GIE Generate Irreversible Error GLC Generate Lewd Comment GMC Generate Machine Check GMCC Generate Machine Check and Cash GND Guess at Next Digit GOD Generate Output Device GORS GO Real Slow GRAB Generate Random Address & Branch GREM Generate Random Error Message GREP Global Ruin, Expiration and Purgation [UNIX] GRMC Generate Rubber Machine Check GS Get Strange [ randomly inverts bits being fed to the instruction decoder" GSB Gulp and Store Bytes GSI Generate Spurious Interrupts GSU Geometric Shift Up HAH Halt And Hang HCF Halt & Catch Fire HCP Hide Central Processor [ makes virtual CPU's act like virtual memories" HCRS Hang in Critical Section HDO Halt and Disable Operator HDRW Halt and Display Random Word HELP Type "No help available" HF Hide a File HGD Halt, Get Drunk HHB Halt and Hang Bus HIS Halt in Impossible State HOO Hide Operator's Output HRPR Hang up and Ruin Printer Ribbon HUAL Halt Until After Lunch IA Illogical And IAI Inquire and ignore IAND Illogical And IBR Insert Bugs at Random ICB Interrupt, crash and burn ICM Immerse Central Memory ICMD Initiate Core Melt-Down ICSP Invert CRT Screen Picture IDC Initiate Destruct Command IDI Invoke Divine Intervention IDPS Ignore Disk Protect Switch IEOF Ignore End Of File IF Invoke Force IGI Increment Grade Immediately IGIT Increment Grade Immediately Twice II Inquire and Ignore IIB Ignore Inquiry & Branch IIC Insert Invisible Characters IIL Irreversable Infinite Loop IM Imagine Memory IMPG IMPress Girlfriend INCAM INCrement Arbitrary Memory location INOP Indirect No-op IO Illogical Or IOI Ignore Operator's Instruction IOP Interrupt processor, Order Pizza IOR Illogical OR IP Increment and Pray IPS Incinerate Power Supply IPS Increment Processor Status IPT Ignite Paper Tape IRB Invert Record & Branch IRB Invert Record and Branch IRC Insert Random Commands IRE Insert Random Errors IRPF Infinite Recursive Page Fault ISC Ignore Supervisor Calls ISC Insert Sarcastic Comments ISI Ignore Silly Instructions ISI Increment and Skip on Infinity ISP Increment and Skip on Pi ITML Initiate Termites into Macro Library IU Ignore User JAA Jump Almost Always JFM Jump on Full Moon JHRB Jump to H&R Block JIL Jump In Lake JM Jump Maybe JMAT JuMp on Alternate Thursdays JNL Jump when programmer is Not Looking JOM Jump Over Moon JRAN Jump RANdom [ not to be confused with IRAN - Idiots random" JRCF Jump Relative and Catch Fire JRGA Jump Relative and Get Arrested JRN Jump RaNdom JRSR Jump to Random Subroutine JT Jump if Tuesday JTR Jump To Register JTZ Jump to Twilight Zone JUMP don't JUMP JWN Jump When Necessary KCE Kill Consultant on Error KUD Kill User's Data LAGW Load And Go Wrong LAP Laugh At Program(mer) LBTPS Let's Blow This Popsicle Stand (Context switch) LCC Load & Clear Core LCD Load and Clear Disk LCK Lock Console Keyswitch LEB Link Edit Backwards LIA Load Ineffective Address LMB Lose Message & Branch LMO Load and Mug Operator LMYB Logical MaYBe LN Lose inode Number [UNIX] LOSM Log Off System Manager LP%PAS Line Printer - Print And Smear LP%RDD Line Printer - Reverse Drum Direction LP%TCR Line Printer - Tangle and Chew Ribbon LPA Lead Programmer Astray LRD Load Random Data LSBL Lose Super BLock [UNIX only] LSPSW Load and scrample PSW LWM Load Write-only Memory MAB Melt Address Bus MAN Make Animal Noises MAZ Multiply Answer by Zero MBC Make Batch Confetti MBH Memory Bank Hold-up MBTD Mount Beatles on Tape Drive MBTOL Move Bugs to Operator's Lunch MC Move Continuous MD Move Devious MDB Move & Drop Bits MDDHAF Make Disk Drive Hop Across Floor MLP Multiply and Lose Precision MLR Move & Loose Record MLSB Memory Left Shift & Branch MMLG Make Me Look Good MNI Misread Next Instruction MOP Modify Operator's Personality MOU MOunt User [causes computer to screw you once again] MOVC Move Computer MPLP Make Pretty Light Pattern MSGD Make Screen Go Dim MSIP Make Sure Plugged In MSR Melt Special Register MST Mount Scotch Tape MT%HRDV MagTape - High speed Rewind and Drop Vacuum MTI Make Tape Invalid MW Malfunction Whatever MWC Move & Wrap Core MWT Malfunction Without Telling NEGP NEGate Programmer NTGH Not Tonight, I've Got a Headache OCF Open Circular File OH OverHeat OML Obey Murphy's Law OPP Order Pizza for Programmer OSI Overflow Stack Indefinitely OTL Out To Lunch PADZ Pack Alpha & Drop Zones PAS Print And Smear PAUD PAUse Dramatically PAZ Pack Alpha Zone PBC Print & Break Chain PBD Print and Break Drum PBM Pop Bubble Memory PBPBPBP Place Backup in Plain Brown Paper Bag, Please " for stealing code" PBST Play Batch mode Star Trek PCI Pleat Cards Immediate PCR Print and Cut Ribbon PD Punch Disk PEHC Punch Extra Holes in Cards PFE Print Floating Eye [Roguers look out!] PFML Print Four Million Lines PI Punch Invalid PIBM Pretend to be an IBM PIC Print Illegible Characters PIC Punch Invalid Character PIRI Print In Red Ink PLSC Perform light show on console PNRP Print Nasty Replies to Programmer PO Punch Operator PPA Print Paper Airplanes PPL Perform Perpetual Loop PPP Print Programmer's Picture PPSW Pack program status word PRS PRint and Smear PSP Print and Shred Paper PSP Push Stack Pointer PSR Print and Shred Ribbon QBB Query Bit Bucket QWA Quit While Ahead ------------------------------------------------------------------------ OP CODES PART III (R - Z) ========================= (Contributed By Knappy 8350428 @ UWAVM) mnemonic meaning -------- ------- RA Randomize Answer RAM Reorganize and Abort Monitor RASC Read And Shred Card RAST Rewind And Stretch Tape RAU Ridicule All Users RBAO Ring Bell and Annoy Operator RBG Random Bug Generate RBLY Restore Backup from Last Year RBT Read & Break Tape RCAJ Read Card And Jam RCB Read Commands Backwards RCB Run Clock Backwards RCC Read Card and Chew RCCP Randomly Corrupt Current Process RCF Rewind Cabinet Fans RCKG Read Count Key and Garbage RCR Rewind Card Reader RCRV Randomly Convert to Reverse Video RCSD Read Card & Scramble Data RD Rewind Disk RDA Refuse to Disclose Answer RDD Reverse Disk Drive RDF Randomize Directory Filenames RDI Reverse Drum Immediate RENVR Rename Variables Randomly RET Read and Erase Tape RIC Rotate Illogical thru Carry RID Read Invalid Data RIR Read Invalid Record RIRG Read Inter-Record Gap RIRG Rewrite Inter-Record Gap [random replacement of simil- ar mnemonic" RLC Re-read last card RLC Relocate and Lose Core RLI Rotate Left Indefinitely RLP Refill Light Pen RLP Rewind Line Printer RM Re-initialize Meter RM Ruin My files [UNIX] RMI Randomize Memory Immediate RMV Remove Memory Virtues RN Read Noise RNBS Reflect Next Bus Signal RNR Read Noise Record ROD ROtate Diagonally ROM Read Operator's Mind ROOP Run Out Of Paper ROPF Read Other People's Files ROS Reject Op System ROT Rotate Disk [fixes broken drives] RP Read Printer RPAB Read Print And Blush RPB Raise Parity Bits RPB Reverse Parity & Branch RPD Return Postage Due RPM Read Programmer's Mind RPU Read character and Print Upside down RRB Read Record and Blush RRC Rotate Random thru Carry RRRA Read Record & Run Away RRRL Random Rotate Register Left RRSG Round and Round She Goes... RS Random Slew RSD Read and Scramble Data RST Rewind and Stretch Tape RST Rust RT Reduce Throughput RT Reverse Throughput RTR Return To Register RTS Return To Sender RWRT Read While Writing While Ripping Tape SAC stop air conditioner SAD Seek And Destroy SAF Sit And Flicker SAI Skip All Instructions SAS Sit And Spin SC Scramble Channels SC Shred Cards SCB Spindle Card and Belch SCCA Short Circuit on Correct Answer SCH Slit Cards Horizontal SCI Shred Cards Immediate SCOM Set Cobol-Only Mode SCRRC SCRamble Register Contents SCST Switch Channel to Star Trek SCTR Stick Card To Reader SD Scramble Directory SD Slip Disk SDC Spool Disk to Console SDDB Snap Disk Drive Belt SDE Solve Differential Equations SDI Self Destruct Immediately SEB Stop Eating and Burp SEX Set EXecution register [a real instruction for the RCA 1802" SEX Sign EXtend SFH Set Flags to Half mast SFT Stall For Time SFTT Strip Form Tractor Teeth SHB Stop and Hang Bus SHCD SHuffle Card Deck SHIT Stop Here If Thursday SHON Simulate HONeywell CPU [permanent NO-OP] SHRC SHRed Card SHRT SHRed Tape SID Switch to Infinite Density SIP Store indefinite precision SKIP don't SKIP SLD Slip Disk SLP Sharpen Light Pen SLP Sharpen Light Pencil SMC Scramble memory contents SMD Spontaneous Memory Dump(Use only with classified data) SMS Shred Mylar Surface SMT Stretch MagTape SNM Show No Mercy SOAWP SOlve All the World's Problems SOB [a real PDP-11 instruction] SOD Surrender Or Die! SOP Stop and Order Pizza SOS Sign Off, Stupid SP Scatter Print SPA Sliding Point Arithmetic SPD Spin dry disc SPS Smoke Power Supply SPSW Scramble Processor Status Word SRBO Set Random Bits to Ones SRBZ Set Random Bits to Zeroes SRC Skip to Random Channel SRCC Select Reader & Chew Cards SRD Switch to Random Density SRDR Shift Right, Double Ridiculous SRO Sort with Random Ordering SRR Set Registers to Random values [ usually used prior to a RET or RTS" SRR Shift Registers Random SRSD Seek Record & Scar Disk SRU Signoff Random User SRZ Subtract & Reset to Zero SSB Scramble Status Byte SSD Stacker Select Disk SSJ Stacker Select & Jam SSJP Select Stacker and Jump SSM Solve by Supernatural Means SSP Smoke and SPark SST Stop and Stretch Tape ST Set and Test STD Stop, Take Drugs STN Search Tree for Nut STPR SToP Rain STTHB Set Terminal to Three Hundred Baud SU Stacker Upset SUI Subtract User's IQ SUME SUrprise ME SUP Solve Unsolvable Problem SUR Screw Up Royally SUS Stop Until Spring SUS Subract Until Senseless SWAT SWAp Terminals SWN SWap Nibbles SWOS SWap out Operating System SWS Sort to Wrong Slots SZD Switch to Zero Density TARC Take Arithmetic Review Course TBFTG Two Burgers and Fries To Go TDB Transfer & Drop Bits TDB Transfer and Drop Bits TDS Trash Data Segment TEP Terminate with Extreme Prejudice TLNF Teach me a Lesson I'll Never Forget TLO Turn indicator Lights Off TLR Transfer & Loose Return TLW Transfer and Lose Way TN Take a Nap TOG Time Out, Graduate TOH Take Operator Hostage TOOO Turn On/Off Operator TOS Trash Operating System TPD Triple Pack Decimal TPE Translate Programmer to EBCDIC TPDH Tell Programmer to Do it Him/Herself TPO Toggle Power On TPR Tear PapeR TR Turn into Rubbish [UNIX] TRA Te Rdls Arvs [Type Ridiculous Abbreviations] TSH Trap Secretary and Halt TSM Trap Secretary and Mount TST Trash System Tracks TT%CNK TeleType - Clunk Noise TT%EKB TeleType - Electrify KeyBoard TTA Try, Try Again TTITT Turn 2400 foot tape Into Two 1200 foot tapes " Only privileged users will get hubs on both tapes" TTL Time To Log off UAI Use Alternate Instruction set UCB Uncouple CPU and Branch UCK Unlock Console Keyswitch UCPUB Uncouple CPU & Branch UER Update & Erase Record UMR Unlock Machine Room UNPD Unplug and dump UOP Useless Operation UP Understand Program(mer) UT Update Transaction UTF Unwind Tape onto Floor UUBR Use Undefined Base Register VAX Violate All executions VNO Violate Noise Ordinance VPA Vanishing Point Arithmetic VVM Vaporise Virtual Memory WAD Walk Away in Disgust WC Waste Core [UNIX] WCR Write to Card Reader WGPB Write Garbage in Process-control Block WHP Wave Hands over Problem WI Why Immediate WID Write Invalid Data WLBB Write-Lock Bit Bucket WNHR Write New Hit Record WNR Write Noise Record WPET Write Past End of Tape WSE Write Stack Everywhere WSWW Work in Strange and Wondrous Ways WUPO Wad Up Printer Output WWLR Write Wrong Length Record XIO eXecute Invalid Op code XKF eXecute Kermit the Frog XMB eXclusive MayBe XOH eXecute no-Op and Hang XOR eXecute OperatoR XOS eXchange Operator's Sex XPR eXecute Programmer XPSW eXecute Program Status Word XVF eXchange Virtue for Fun ZAP Zero and Add Packed ZD Zap Directory ZNL Zero Next Location (opcode #0) ZPI ZaP Immediate ZPT Zero Page Tables ZZF Zero Zero Flag ZZZ hibernate indefinite