Undocumented assembler opcodes
This document found floating around IBM's St. Louis office
- AAC
- Alter All Commands
- AAD
- Alter All Data
- AAR
- Alter At Random
- AB
- Add Backwards
- ABR
- Add Beyond Range
- ACQT
- Advance Clock to Quitting Time
- ADB
- Another Damn Bug (UNIX)
- AFF
- Add Fudge Factor
- AFHB
- Align Fullword on Halfword Boundary
- AGB
- Add GarBage
- AI
- Add Improperly
- AIB
- Attack Innocent Bystander
- AMI
- Adjust Memory for Inflation
- AOI
- Annoy Operator Immediate
- AR
- Alter Reality
- ARN
- Add and Reset to Non-zero
- AS
- Add Sideways
- AWP
- Argue With Programmer
- AWTT
- Assemble With Tinker Toys
- BAC
- Branch to Alpha Centurai
- BAF
- Blow All Fuses
- BAH
- Branch And Hang
- BAM
- Branch After Midnight
- BB
- Branch on Bug
- BBI
- Branch on Burned-out Indicator
- BCF
- Branch and Catch Fire
- BCIL
- Branch Creating Infinite Loop
- BCR
- Backspace Card Reader
- BCU
- Be Cruel and Unusual
- BDC
- Break Down and Cry
- BDM
- Branch and Disconnect Memory
- BDT
- Burn Data Tree (follows Decorate Data Tree)
- BE
- Branch Eventually
Branch Everywhere
- BF
- Belch Fire
- BLP
- Boot from Line Printer
- BLM
- Branch, Like, Maybe
- BLMWM
- Branch, Like, Maybe, Wow, Man
- BLSC
- Branch on Lapsed Service Contract
- BM
- Branch to Monday
- BMP
- Branch and Make Popcorn
- BNA
- Branch to Nonexistent Address
- BNO
- Branch on New Operator
- BNR
- Branch for No Reason
- BPEOR
- Bypass End Of Reel
- BPIM
- Bury Programmer In Manuals
- BPP
- Branch on Programmer Present
- BRA
- BRanch Anywhere
- BRL
- BRanch and Leak
- BSM
- Branch and Scramble Memory
- BSST
- Backspace and Stretch Tape
- BT(BRT)
- Branch on Tuesdays
- BTK
- Back To Kansas
- BW
- Branch on Whim
- BWOP
- BeWilder OPerator
- CAAL
- Compute Answer And Loop
- CAB
- Crash And Burn
- CAG
- Convert ASCII to Greek
- CAIL
- Crash After I Leave
- CAT
- Confused And Tired (UNIX)
- CBA
- Compare and Branch Anyway
- CBNC
- Close, But No Cigar
- CC
- Call Cavalry
- CCD
- Clear Core and Dump
- CEE
- Cause Errors Elsewhere
- CF
- Come From
- CH
- Create Havoc
- CIB
- Change Important Byte
- CIMM
- Create Imaginary Memory Map
- CL
- Call Lawyer
- CMD
- Compare Meaningless Data
- CMI
- Clobber Monitor Immediate
- CML
- Compute Meaning of Life
- CNB
- Cause Nervous Breakdown
- COLB
- Crash for Operator's Lunch Break
- COS
- Copy Object code to Source file
- COWHU
- Come Out With Hands Up
- CPB
- Create Program Bug
- CPR
- Compliment PRogrammer (like, "aren't you cute")
- CRASH
- Continue Running After Stop or Halt
- CRM
- Clear Random Memory
- CRN
- Convert to Roman Numerals
- CS
- Crash System
- CSL
- Curse and Swear Loudly
- CSN
- Call Supervisor Names
- CVFL
- ConVert Floating to Logical
- CVFP
- ConVert Fortran to Pascal
- DA
- Develop Amnesia
- DAP
- De-select Active Peripheral
- DBL
- Desegregate Bus Lines
- DBZ
- Divide By Zero
- DC
- Degauss Core
- DCGC
- Dump Confusing Garbage to Console
- DD
- Destroy Disk
- DDC
- Dally During Calculations
- DDWB
- Deposit Directly in Wastepaper Basket
- DEC
- Decompile Executable Code
- DIE
- DIsable Everything (UNIX during hardware errors?)
- DIRFO
- Do It Right For Once
- DK
- Destroy Klingons
- DKP
- Disavow Knowledge of Programmer
- DLN
- Don't Look Now
- DMAG
- Do MAGic (the only command a programmer really needs)
- DMPE
- Decide to Major in Phys Ed
- DPC
- Decrement Program Counter
- DPMI
- Declare Programmer Mentally Incompetent
- DSI
- Do Something Interesting
- DSTD
- Do Something Totally Different
- DSUITv
- Do Something Utterly, Indescribably, Terrible
- DTC
- Destroy This Command
- DTI
- Do The Impossible
- DTVFL
- Decrement Third Variable From Left
- DWIM
- Do What I Mean
- EBB
- Empty Bit Bucket
- EBRS
- Emit Burnt Resistor Smell
- ECO
- Electrocute Computer Operator
- ECP
- Erase Card Punch
- EDD
- Eat Disk and Die
- EDIT
- Erase Data and Increment Time
- EEP
- Erase Entire Program
- EIAO
- Execute In Any Order
- EIOP
- Execute Invalid OPcode
- ENA
- Enable Anything
- ENF
- Emit Noxious Fumes
- EOB
- Execute Operator and Branch
- ERM
- Erase Reserved Memory
- EROM
- Erase Read Only Memory
- ESL
- Exceed Speed of Light
- ESS
- Enable Sprinkler System
- EXX
- (a real instruction on the Zilog Z-80) (Zilog is owned by Exxon)
- FB
- Find Bugs
- FD
- Forget Data
- FLD
- FLing Disk
- FLI
- Flash Lights Impressively
- FM
- Forget Memory
- FRG
- Fill with Random Garbage
- FSM
- Fold, Spindle, and Mutilate
- GBC
- Go to the Back of the Class
- GCAR
- Get Correct Answer Regardless
- GDP
- Grin Defiantly at Programmer
- GIE
- Generate Irreversible Error
- GND
- Guess the Next Digit
- GORS
- GO Real Slow
- GPS
- Give Programmer the Shaft
- GREP
- Global Ruin, Expiration and Purgation (UNIX)
- HAH
- Halt And Hang
- HCRS
- Hang in CRitical Section
- HELP
- type "no HELP available"
- HF
- Hide a File
- HOO
- Hide Operator's Output
- IBR
- Insert Bugs at Random
- IDI
- Invoke Divine Intervention
- ILI
- Ignore Last Instruction
- IP
- Increment and Pray
- IPW
- Invert Print Wheel
- ISC
- Insert Sarcastic Comment
- ISP
- Increment and Skip on Pi
- IU
- Ignore User
- JAA
- Jump Almost Always
- JFI
- Jump to Following Instruction
- JFM
- Jump on Full Moon
- JLP
- Jump and Lose Pointer
- JNL
- Jump when programmer Not Looking
- KP
- Krunch Paper
- KUD
- Kill User's Data
- LB
- Look Busy
- LOSM
- Log Off System Manager
- LPA
- Lead Programmer Astray
- LSPB
- Left Shift Parity Bits
- MAN
- Make Animal Noises (UNIX)
- MAZ
- Multiply Answer by Zero
- MBTD
- Mount Beatles on Tape Drive
- MBTOL
- Move Bugs To Operator's Lunch
- MDB
- Move and Drop Bits
- MDDHAF
- Make Disk Drive Hop Across Floor
- MLP
- Make Lousy Program
- MMLG
- Make Me Look Good
- MNI
- Misread Next Instruction
- MRZ
- Make Random Zap
- MWT
- Malfunction Without Telling
- OML
- Obey Murphy's Law
- PBC
- Print and Break Chain
- PBM
- Pop Bubble Memory
- PEHC
- Punch Extra Holes in Card
- PIBM
- Pretend to be an IBM
- POW
- Print Obscene Words
- PUL
- Print in Unknown Language
- RA
- Randomize Answers
- RAU
- Ridicule All Users
- RBAO
- Ring Bell and Annoy Operator
- RBEOR
- Read Beyond End Of Reel
- RCB
- Read Commands Backward
- RCR
- Rewind Card Reader
- RDA
- Refuse to Disclose Answer
- RDCH
- Read Disk and Crash Head
- RDI
- Reverse Disk Immediate
- RENVR
- REName Variables Randomly
- RF
- Read Fingerprints
- RHP
- Read Hub Protector
- RLI
- Rotate Left Indefinitely
- RLP
- Refill Light Pen
- RPB
- Read, Print and Blush
- RTP
- Reduce ThroughPut
- SAI
- Skip All Instructions
- SAS
- Sit And Spin
- SDD
- Seek out and Destroy Data
- SDE
- Solve Differential Equations
- SFH
- Set Flags to Half-mast
- SFT
- Stall For Time
- SOS
- Sign Off, Stupid
- SPS
- Smoke Power Supply
- SRO
- Sort with Random Ordering
- SSJ
- Select Stacker and Jam
- STO
- Strangle Tape Operator
- STPR
- SToP Rain
- SUI
- Subtract User's IQ
- SUP
- Solve Unsolvable Problem
- SUR
- Screw Up Royally
- SUS
- Stop Until Spring
- SWT
- Select Wrong Terminal
- TARC
- Take Arithmetic Review Course
- TBGTG
- Two BurGers and fries To Go
- TC
- Transmit Colors
- TCAR
- Transmit Colors, but Avoid Red
- TLO
- Turn indicator Lights Off
- TLW
- Transfer and Lose Way
- TN
- Take a Nap
- TPDH
- Tell Programmer to Do it Him/Her self
- TRA
- Te Rdls Arvs (Type Ridiculous Abbreviation)
- TT%EKB
- TeleType - Electrify Keyboard
- TTA
- Try, Try Again
- TTL
- Tap Trunk Line
- UAI
- Use Alternate Instruction set
- UCB
- Uncouple Comm lines and Break
- UEP
- Update and Erase Program
- UP
- Understand Program
- VAX
- Violate All eXecutions
- VFO
- Violate Female Operator
- VMA
- Violate Maintenance Agreement
- VNO
- Violate Noise Ordinance
- VVM
- Vaporize Virtual Memory
- VW
- Void Warranty
- WAD
- Walk Away in Disgust
- WBF
- Write Bad File
- WDI
- Write Data and Ignore
- WHP
- Wave Hands over Problem
- WQWH
- Write Quietly With Hangover
- WSWW
- Work in Strange and Wondrous Ways
- XKF
- eXecute Kermit the Frog
- XMB
- eXclusive MayBe
- XOS
- eXchange Operator's Sex
- YKWIM
- You Know What I Mean
And some miscellaneous non-instructions
- IBM
- It's Better Manually
I've Been Moved
Intimidated, Buffaloed Management
Insultingly Boring Merchandisers
Itty Bitty Machine
Ingrained Batch Mentality
Intelligence Belittling Mammoth
I Bought Macintosh
Incest Begets Madness
Intellectuals Being Moronized
Inspect Before Multiusing
Inertia Breeds Mediocrity
It Beats Mattel
Insipid Belligerent Mossbacks
Imperialism By Marketing
Institution By Machiavelli
Into Building Money
Irresponsibly Behaved Multinational
Impentrable Brain Matter
Itsa Big Mess
Ingenuity Becoming Mysterious
Intolerant of Beards and Mustaches
Install Bigger Memory
- RAM
- Rarely Available Memory
- SPA
- Sliding Point Arithmetic
- VPA
- Vanishing Point Arithmetic
- WOM
- Write Only Memory