Dec 312017
Undocumented Intel 8088 opcodes.
File XTND8088.ZIP from The Programmer’s Corner in
Category Various Text files
Undocumented Intel 8088 opcodes.
File Name File Size Zip Size Zip Type
XTND8088.TXT 10240 4098 deflated

Download File XTND8088.ZIP Here

Contents of the XTND8088.TXT file




The following op-codes have been recently uncovered on the back of several
used bar napkins in Silicon Valley, CA. Several attempts have been made to get
confirmation of these heretofore unknown codes, but Intel vehemently denies the
existence of these in the 8088/8086 command set.

Several man-years have gone into the research of these codes. We would like to
thank the programmer's responsible for discovering them. Unfortunately, most
of them are currently residents of the Northern South Dakota Home for the
Mentally Deranged and are unable to receive mail. We hope they recover

A final warning is in order. Since Intel denies the existence of these codes,
support of them cannot be guaranteed in subsequent hardware and/or software
releases. Therefore please use with caution.

-------- -----------
AAC Alter All Commands
AAR Alter at Random
AB Add Backwards
ACQT Advance clock to quitting time (works best on Fridays)
AFVC Add Finagle's Variable Constant
BAFL Branch and Flush
BAH Branch and hang
BALFR Branch and leave from root
BBT Branch on Binary Tree
BBW Branch Both Ways
BCIL Branch Creating Infinite Loop
BEL Branch to endless loop
BEW Branch Either Way
BH Branch and Hang
BHDC Back-up hard disk pack to cassette
BIA Branch to invalid address
BMR Branch Multiple Registers
BOB Branch on Bug
BODI Branch on date indexed
BPDI Be Polite, Don't Interrupt
BPO Branch on Power Off
BSE Backspace and erase
BST Backspace and Stretch Tape
CAH Crash all heads
CBNC Close, but no Cigar (error response)
CDS x Change drive speed (x = 16; 33-1/3; 45; 78 rpm)
CEMU Close Eyes and Monkey With User Space
CHA x Change head alignment (-128 <= x <+ 127 cm)
CLBR Clobber Register
CLBRI Clobber Register Immediately
CM Circulate Memory
CMD Compare Meaningless Data
CMI Clobber monitor immediate
CNR Call subroutine (no return)
CPR Crumple Printer Paper and Rip
CRASH Continue Running After Stop or Halt
CRN x Convert to roman numerals (specify base x)
CRSO Check if red switch is off
CSI Crash System Immediate
CSO Change screen to orange
CTN Compare age to Noah
CU Convert to Unary
CVG Convert to Garbage
CWOM Complement Write-only Memory
DAK Disable keyboard
DAP Deselect active peripherals
DBZ Divide by Zero
DC Divide and Conquer
DDC Delay During Calculations
DMNS Do What I Mean, Not What I Say
DMPK Destroy Memory Protect Key
DNPG Do Not Pass Go
DO Divide and Overflow
DPR Destroy Program
DSH Destroy sector header
DTC Destroy This Command
DTVFL Destroy Third Variable From Left
DUD Discard un-necessary data
DWIT Do what I'm thinking (works intermittently)
EAO Encrypt all output
EBB Edit and Blank Buffer
ED Eject disk
EDF Erase data file
EDR Execute destructive read
EEO Execute Every Other Instruction
EIAO Execute In Any Order
EIOC Execute Invalid Op-code
EMPC Emulate Pocket Calculator
EMSE Edit and Mark Something Else
EP Execute Programmer
EPI Execute Programmer Immediately
ERM Erase reserved memory
EROS Erase Read-only Storage
EX Exchange data with inter-record gap
FDL Force a deadlock
FDL Free a deadlock
FFC Form feed (continuous)
FLI Flash Lights Impressively
FOPC (set) False out of paper condition
FS False start
FSM Fold, Spindle and Mutilate
GDO Ground data one line
GFD Go Forth and Divide
GFM Go Forth and Multiply
GOZ Goto ozone
HCF Halt and catch fire
HCP Hide Central Processor
HRPR Hang up and ruin printer ribbon
IAE Ignore All Exceptions
IBM Illogical branch or move
IBP Insert Bug and Proceed
IDPS Ignore disk protect switch (or tab)
IEOF Ignore end of file
IF Ignore format
IGOTO Ignore goto instructions (bad structure!)
IIB Ignore interrupt and branch
JCH Jump if current is high
KGB Kill Gargantuan dataBase files
LAO Logical And and Or
LCC Load and Clear Core
LDSA Load ds register with disk A:
LK Lockup keyboard
MAC Move AC-in to stdout
MAZ Multiply Answer by Zero
MFN Make funny noise
MLR Move and Lose Record
MOS Move operating system
MPS Move result to power supply register
MRPR Move results to power supply register
OML Obey Murphy's Laws
PBB x Pack byte information into bit position x
PBC Print and Break Chain
PBD Print and break drum (who remembers those?)
PIC Punch invalid code
PPL Perform perpetual loop (reach for red switch)
PSO Punch system operator (careful with this Clarke)
PVLC Punch Variable Length Card
PWP Pizza with pepperoni
RA Randomize Answer
RASC Read and Shred Card
RAST Read and shred tape
RB Regulate screen Brightness [+|-]
RBPK Roll Back Platen Knob
RCB Read Command Backwards
RD Reverse Directions
RDA Refuse to Disclose Answer
RDB Run Disk Backwards
RDC Randomize data & control bus
RDD Randomize disk directory
RDI Reverse disk immediate
RDR Read disk reversed
RDS Read Sideways
REINK ReInk Ribbon
RFAT x Restore File Allocation Table [-x] (in day increments)
RFF Reverse form feed
RIP Randomize instruction pointer
RIR Read invalid record
RIRG Read Inter-record Gap
RKC Randomize keyboard configuration (for security)
RLF Reverse line feed
RLI Rotate Left Indefinitely
RO Roman numeral offset
ROC Randomize Op Codes
ROD rotate down
ROU rotate up
RS Random slew (usually best for plotters)
RSD Random slew display
RSP Randomize stack pointer
RSS Reset system
RST Rewind and snap tape
RSTOM Read From Store-only Memory
RWCR Rewind Card Reader
SAI Skip All Instructions
SAP Signal all processes
SAS Sit And Spin
SAT Scramble allocation table
SFH Set Flags to Half-mast
SFTT Strip form tractor teeth
SHAB Shift a Bit
SHABM Shift a Bit More
SIP Scramble ISAM pointers
SLP Sharpen Light Pen
SMD Spontaneous memory dump
SMR Skip on Meaningless Result
SNL Stop if not level
SNP Shutdown if nuclear powered
SOBR Skip over bad RAM chip
SOZ Set available output devices to zero
SPS Set Panel Switches
SPSW Scramble Program Status Word
SPTO Set power to off
SPTO Set power to on
SPTO Set printer to off
SPTO Set printer to on
SPTO Set printer to out-of-order
SPTO Set stack pointer to zero
SR Scramble registers
SRDR Shift Right Double Ridiculous
SRIS Set reciprocal of interrupt status
SRRL Shift Right, Rotate Left register contents (zeros register)
SRSD Seek record and scar disk
SRZ Subtract and Reset to Zero
SSB Scramble status byte
SSJ Select stacker and jam
SSM shift structure member [+|-]
STA Store Anywhere
STROM Store in Read-only Memory
TDB Transfer and Drop Bits
TG Thank God
TLO Turn Indicator Lights Off
TOCR Tell operator to change ribbon
TPF Turn Power Off
TPN Turn Power On
TTS Translate to Sanskrit
UCB Uncouple CPU and Branch
UDR Update and delete record
UER Update and Erase Record
ULDA Unload Accumulator
UPCI Update Card In Place
UKB Unplug keyboard (inhibits user intervention)
WBT Water Binary Tree
WEMG Write Eighteen Minute Gap
WF Wait Forever
WI Write Illegibly
WUPO Wad up paper output
WWLR Write Wrong-Length Record
XTAT Transform XT to an AT
ZAR Zero Any Register
ZCS Zero code segment
ZD Zap directory
ZM Zero or zap microprocessor

OTHERS? . . .

One collection of new opcodes was one that I collected for the Michigan Technic
(at Univ. of Michigan) several years ago (which is probably where the person
from U of M copied it from...) "The Technic Guide to Assembler Language"
appeared in two parts and was the "best" of some 250 opcodes that I invented,
got from friends, or found in various locations (from the library to East
Engineering Bldg bathrooms) at the school. The list that follows contains most
of them, and a few more that people here (at Intermetrics) have added to the
list. Enjoy.

Jeff Diewald
Intermetrics, Inc.

 December 31, 2017  Add comments

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