6502 error conditions
Craig Scott Lennox
What does the 6502 do when it encounters an illegal
opcode? Does it just halt, as in a BRK, or can you have
it branch to a trap address?
--
| flame me at: len...@minilove.diag.stratus.com, (Craig Scott Lennox) |
|"Oh boy, virtual memory! Now I'm gonna make myself a REALLY BIG ram disk!" |
| Disclaimer: My opinions are covered by section 2b of the Gnu Public |
| License and thus do not belong to Stratus Computer. |
Gary Duzan
=>
=>
=>What does the 6502 do when it encounters an illegal
=>opcode? Does it just halt, as in a BRK, or can you have
=>it branch to a trap address?
=>
I believe the result is undefined. In fact, some early 6502's had some
desirable side-effects of using an undocumented opcode, so programmers would
use them. Obviously a bad thing. Newer chips like the 65802 and the 65816
actually use all 256 bit patterns for opcodes. (Well, just about anyway.)
Answer: Don't do that. (0.5 :-)
Gary Duzan
Time Lord
Third Regeneration
--
gdt...@freezer.it.udel.edu
_o_ -------------------------- _o_
[|o o|] An isolated computer is a terribly lonely thing. [|o o|]
|_O_| "Don't listen to me; I never do." -- Doctor Who |_O_|
Craig Scott Lennox
In article <LENNOX.90S...@minilove.diag.stratus.com> len...@minilove.diag.stratus.com (Craig Scott Lennox) writes:
=>What does the 6502 do when it encounters an illegal
=>opcode? Does it just halt, as in a BRK, or can you have
=>it branch to a trap address?
I believe the result is undefined. In fact, some early 6502's had some
desirable side-effects of using an undocumented opcode, so programmers would
use them. Obviously a bad thing. Newer chips like the 65802 and the 65816
actually use all 256 bit patterns for opcodes. (Well, just about anyway.)
Answer: Don't do that. (0.5 :-)
Well that's depressing. I was hoping there would be an illegal opcode
trap to implement new opcodes.
Guess I won't even ask if there's an illegal memory ref trap address
to use to implement virtual memory. (0.125 :-) )
The really depressing thing is: How tough could it have been? I
realise that the 6502 microcode really packs 'em in, but it's
pretty poor programming style not to handle error conditions.
Gary Duzan
=>
=> In article <LENNOX.90S...@minilove.diag.stratus.com> len...@minilove.diag.stratus.com (Craig Scott Lennox) writes:
=> =>What does the 6502 do when it encounters an illegal
=> =>opcode? Does it just halt, as in a BRK, or can you have
=> =>it branch to a trap address?
=>
=> I believe the result is undefined. In fact, some early 6502's had some
=> desirable side-effects of using an undocumented opcode, so programmers would
=> use them. Obviously a bad thing. Newer chips like the 65802 and the 65816
=> actually use all 256 bit patterns for opcodes. (Well, just about anyway.)
=> Answer: Don't do that. (0.5 :-)
=>
=>
=>Well that's depressing. I was hoping there would be an illegal opcode
=>trap to implement new opcodes.
=>
=>Guess I won't even ask if there's an illegal memory ref trap address
=>to use to implement virtual memory. (0.125 :-) )
=>
The 65816 could possibly handle Virtual Memory with some extra hardware
since it has an ABORT input signal to abort the current instruction and jump
through an additional interrupt vector. I wouldn't think it possible on a 6502,
however.
=>The really depressing thing is: How tough could it have been? I
=>realise that the 6502 microcode really packs 'em in, but it's
=>pretty poor programming style not to handle error conditions.
=>
Well, I think they at least made sure that the thing doesn't get stuck in
a funny state when the illegal opcodes are refernced. I can't speak to the
complexity issue; I gave up EE long ago. (Three whole years. :-) The only
argument I can give for their decision was to keep the chip simple. By the way,
I'm pretty sure the 65C02 made all the unused opcodes NOP's.
=>
=>|"Oh boy, virtual memory! Now I'm gonna make myself a REALLY BIG ram disk!" |
Sounds good to me. The Bullet File System (Amoeba) does something pretty
close to this. It seems to be getting more popular.
Charles K Hughes
>What does the 6502 do when it encounters an illegal
>opcode? Does it just halt, as in a BRK, or can you have
>it branch to a trap address?
The 6502 does several things. Sometimes it executes the illegal instruction,
sometimes it hangs (and I think a powerdown is required to reset it), and
sometimes it executes a NOP. The 65C02 chip executes NOPs when it
encounters an illegal instruction, as does the 65802 and 65816. To my
knowledge, none of the chips simply HALTs or branches to a trap address.
For the 6502, however, you can actually build a circuit that can detect
most of the illegal opcodes, and cause an interrupt if one is about to be
executed. If you want more information on this, send me email. A more
attractive way of avoiding illegal opcodes is to use the 65C02 however. :)
>--
>| flame me at: len...@minilove.diag.stratus.com, (Craig Scott Lennox) |
Charles K Hughes
>Well that's depressing. I was hoping there would be an illegal opcode
>trap to implement new opcodes.
To simulate this, use the BRK opcode.
>
>Guess I won't even ask if there's an illegal memory ref trap address
>to use to implement virtual memory. (0.125 :-) )
To simulate this, wire up a circuit that generates an interrupt if virtual
memory is accessed.
Of course, the solution is to simply use a 68000. It has everything you are
looking for I think.
>
>The really depressing thing is: How tough could it have been? I
>realise that the 6502 microcode really packs 'em in, but it's
>pretty poor programming style not to handle error conditions.
Yes, but at the time the 6502 was created it wasn't really easy programming
them. :)
>
>
>--
>| flame me at: len...@minilove.diag.stratus.com, (Craig Scott Lennox) |
Dale Kim
>What does the 6502 do when it encounters an illegal
>opcode? Does it just halt, as in a BRK, or can you have
>it branch to a trap address?
On the topic of illegal 6502 opcodes, I once heard that there was a
'Crash and Burn' instruction on the Apple II's 6502 chip (which supposedly
melts down the chip). Have any of you 8-bit enthusiasts heard of anything
like this for the 6502 in an Atari computer? I have an expendable Atari 800
at my disposal. :-)
-Dale
Claus Brod
>The really depressing thing is: How tough could it have been? I
>realise that the 6502 microcode really packs 'em in, but it's
>pretty poor programming style not to handle error conditions.
The 6502 has no microcode at all. It's hard-wired. (One of those very
early RISC chips 8-)
----------------------------------------------------------------------
Claus Brod, Am Felsenkeller 2, Things. Take. Time.
D-8772 Marktheidenfeld, West Germany (Piet Hein)
csb...@medusa.informatik.uni-erlangen.de
----------------------------------------------------------------------
Landon Dyer
>The really depressing thing is: How tough could it have been? I
>realise that the 6502 microcode really packs 'em in, but it's
>pretty poor programming style not to handle error conditions.
There's worse. Early 6502s (pre June '76) didn't have ROR.
There were some articles eight or nine years ago that discussed the
"undocumented" 6502 instructions (for some particular mask-version of the
chip, I suppose). Some of them were pretty odd, like "Store A Immediate"
or (memory begins to fail me now:) "TYA and increment S."
More trivia: Leonard Tramiel claimed that the world's record for a "stock"
6502 is 25 Mhz (sans cooling -- the champ got REAL hot before it died).
Anyone for a dry-ice-fueled, six MIP 68K-killer? :-)
Landon Dyer (lan...@apple.com) :::::::::::::::::::::::::::::::::::::::::::::::
:::::::::::::::::::::::::::::::::: making the merry-go-round SPIN FASTER
Apple Computer, Inc. :: so that everyone has to HOLD ON TIGHTER
NOT THE VIEWS OF APPLE COMPUTER :: just to keep from being THROWN TO THE WOLVES
--
Landon Dyer (lan...@apple.com) :::::::::::::::::::::::::::::::::::::::::::::::
:::::::::::::::::::::::::::::::::: making the merry-go-round SPIN FASTER
Apple Computer, Inc. :: so that everyone has to HOLD ON TIGHTER
NOT THE VIEWS OF APPLE COMPUTER :: just to keep from being THROWN TO THE WOLVES
Kit Kimes
>
> =>
> =>|"Oh boy, virtual memory! Now I'm gonna make myself a REALLY BIG ram disk!" |
>
> Sounds good to me. The Bullet File System (Amoeba) does something pretty
> close to this. It seems to be getting more popular.
I have never heard of the Bullet File System. Where can I get a copy. Is
it sold by Atari dealers. I don't think my local one has heard of it
either. At least it has never been brought up at any of our User Group
meetings.
Kit Kimes
AT&T Bell Labs
Naperville, IL
...!att!iwtsa!kimes
Jeff Potter
fire). It stopped all other operations, reset the PC, and started
accessing memory sequentially (from $0000 to $FFFF) at its maximum speed.
Supposedly Motorola designed it as a test feature. No such thing carried
over onto the 6502, though.
--
=======================================================
Jeff Potter
...pot...@ge-dab.ge.com
...mcnc!codas!ge-dab.GE.COM!potter
Rik Harris
>On the topic of illegal 6502 opcodes, I once heard that there was a
>'Crash and Burn' instruction on the Apple II's 6502 chip (which supposedly
>melts down the chip).
I sure hope this is a joke.
> Have any of you 8-bit enthusiasts heard of anything
>like this for the 6502 in an Atari computer? I have an expendable Atari 800
>at my disposal. :-)
I'll post/send a list of lots of these types of opcodes later today or
tomorrow.
>-Dale
rik.
--
Rik Harris - edp...@monu6.cc.monash.edu.au | Build a system that
Faculty of Computing and Information Technology, | even a fool can use,
Monash University, Caulfield Campus, Australia | and only a fool will
(say that with your mouth full!) | want to use it.
David Clear
>On the topic of illegal 6502 opcodes, I once heard that there was a
>'Crash and Burn' instruction on the Apple II's 6502 chip (which supposedly
>melts down the chip). Have any of you 8-bit enthusiasts heard of anything
>like this for the 6502 in an Atari computer? I have an expendable Atari 800
>at my disposal. :-)
I too heard about this. Whether I really believe it or not is another
matter. What I heard is that it was a memory address (maybe for an i/o
device) which, when written to the right way, would send some current to
part of the computer which blew something. Technically, I suppose this
sort of thing is possible, but what a design bug!!!
As for other 6502 opcodes, Personal Computer World (or maybe Practical
Computing - which ever one had the "Subset" section) had a pretty
comprehensive list of "illegal" opcodes back in 1983 (I think). The
instructions were pretty weird - too weird for me to remember. What I
do remember was that I saw no real use for any of them, although there
were two and three byte NOPs with which you can write very sneaky code as
the first byte was the NOP2 or NOP3 code and the next one or two bytes
were just ignored and so could be any other instruction/data you wanted.
Of course, the use of such illegal codes is "bad practice", but then so
is self modifying code and I know no-one who programs 6502 and doesn't
use that :-)
Dave.
--
% cc life.c | David Clear d...@ukc.ac.uk +44 227 764000x7592
% a.out | Local Area Networks, Computing Laboratory,
Segmentation fault (core dumped) | University of Kent, Canterbury, England.
>>> Kernel R0M. His Mission: To rid the world of wobbly ZX-81 16K RAM packs. <<<
Dore Brian K
>>On the topic of illegal 6502 opcodes, I once heard that there was a
>>'Crash and Burn' instruction on the Apple II's 6502 chip (which supposedly
>>melts down the chip). Have any of you 8-bit enthusiasts heard of anything
>>like this for the 6502 in an Atari computer? I have an expendable Atari 800
>>at my disposal. :-)
Dave Clear responds...
>I too heard about this. Whether I really believe it or not is another
>matter. What I heard is that it was a memory address (maybe for an i/o
>device) which, when written to the right way, would send some current to
>part of the computer which blew something. Technically, I suppose this
>sort of thing is possible, but what a design bug!!!
[...]
>Dave.
There was an APRIL FOOLS JOKE about this in an Atari magazine. It
even had a program to type in that did some silly stuff before
trashing the Display List and moving the screen memory pointers
over some active memory area (Page 0 or something) so that the
display went wack. They did get a lot of letters from people who
didn't get the joke.
There was (is) absolutely NO WAY to harm the computer through software.
I am absolutely positive about the Atari, & Apple. I have heard
rumors about the Commodore PET possibly having this problem, but
I don't believe it for a second.
Sure you could rig up someting to trigger a bomb when you run it, but
don't waste our time posting silly stuff like that.
--
Brian K. Dore' Internet : b...@pc.usl.edu
Programmer /Analyst U.S. Mail : PO Box 42770
Computing Center Lafayette, LA 70504
University of Southwestern LA Telephone : (318) 231-6868
David Clear
[ on the subject of suicide instructions ]
>There was an APRIL FOOLS JOKE about this in an Atari magazine. It
>even had a program to type in that did some silly stuff before
>trashing the Display List and moving the screen memory pointers
>over some active memory area (Page 0 or something) so that the
>display went wack. They did get a lot of letters from people who
>didn't get the joke.
Well, in my defense, I heard about this with regards to an Apple (I think),
and from a 3rd party. So if he got it from a magazine, I guess he (we) are
the fools :-)
As for wacky display lists, I have seen some great special effects on the XL
and Amiga due to software crashes which trash the screen info (eg display list
pointer on the XL). In fact, I think I've probably seen more impressive
scrolling, moving graphics during crashes than I have in games!!!! Of course,
seeing your screen bounce up an down, scrolling, changing size etc,etc may
look a little out of place in most games!!! :-)
Dave (older and wiser).
Chris_F...@cup.portal.com
per se, but I do know a little bit about the history of opcodes that burn
out computers.
Whomever mentioned that "it wasn't the opcode, but a memory or hardware
address or register that did it" was correct. I believe there was a con-
trolling register in the early IBM PC that controlled whether or not the
CRT flyback transformer signal was generated and/or actually directed to
the transformer itself; apparently it was possible to send a particular
control bit value to the register which caused the signal sent to the
transformer to become straight DC current, burning out the whole video
subsystem. POOF!
(I heard something even earlier than this, attributed to the Commdore PET
computer, but don't know the details.)
Gary Duzan
=>
=>(I heard something even earlier than this, attributed to the Commdore PET
=>computer, but don't know the details.)
The way I heard it, the PET had the monitor built in, and had full control
over screen width and height. All you had to do was reduce the screen to a
single dot in the middle, and it would slowly fry the monitor.
I also heard that the Vic-20 had a location that cross-wired an I/O port,
causing a power surge into the circuits.
This is all rumor and heresay. I haven't seen/performed any of these.
Gary Duzan
Time Lord
Third Regeneration
p.s. I have, however, seen Apple IIe's get fried by static charges. In High
School, the computer room used to be a library and had this nice carpet...
GD,TL,TR
Norman Lin
It was a single POKE command on the Commodore PET. An early issue of
Compute! Magazine (1982? 83?) actually gave the POKE command; it allowed
the video display chip to run faster. Left unchecked, this would eventually
burn out the display chip.
--
\ /\/\ /\/\ +-----------------------------+ /\/\ /\/\ /./
\\ /./\\\ /./\\\ /====|Norman Lin/nor...@129.15.20.2|===/./\\\ /./\\\ /./
\\\/./ \\\/./ \\\/./===| nor...@uokmax.ecn.uoknor.edu|====/ \\\/./ \\\/./
\/\/ \/\/ \/\/ +-----------------------------+ \/\/ \/\/
Rik Harris
>On the topic of illegal 6502 opcodes, I once heard that there was a
>'Crash and Burn' instruction on the Apple II's 6502 chip (which supposedly
>melts down the chip). Have any of you 8-bit enthusiasts heard of anything
>like this for the 6502 in an Atari computer? I have an expendable Atari 800
>at my disposal. :-)
Here we go again...this was posted to alt.folklore.computers less than 2 weeks
ago:
From: pet...@opus.cs.mcgill.ca (Peter Deutsch)
Newsgroups: alt.folklore.computers
Subject: Re: <None>
Summary: It's a dirty job, but somebody's got to do it....
Message-ID: <22...@opus.cs.mcgill.ca>
Date: 6 Sep 90 17:05:50 GMT
References: <ben....@epmooch.UUCP> <79...@helios.TAMU.EDU> <17...@cygnus.scol.UUCP>
Organization: SOCS, McGill University, Montreal, Canada
Lines: 1067
In article <17...@cygnus.scol.UUCP>, dav...@scol.UUCP (David Gurr) writes:
> dc...@cssun.tamu.edu (David A. Cook) writes:
>
> >In article <ben....@epmooch.UUCP> b...@epmooch.UUCP (Rev. Ben A. Mesander)
> >writes:
> >> If memory serves me right, the old Commodore PET machines could be
> >> physically damaged (ie smoke) by poking the wrong value into the wrong
> >> memory location. Good design...
>
> Didn't there use to be a machine intrsuction that caused this problem?
> Some wag gave it the mnemonic HCF ... Halt and Catch Fire!
Okay, this is bound to kick off a thread that was done to
death a while ago. So what do I do? I participate! :-)
Here's one list of these things...
- peterd
------------------------------------------------------------
MNEMONIC INSTRUCTION
---------- -------------
-A-
AAC Alter All Commands
AAD Alter All Data
AAO Add And Overflow
AAR Alter at Random
AB Add Backwards
ABC AlphaBetize Code
ABR Add Beyond Range
ACC Advance CPU clock
ACDC Allow Controller to die peacefully
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 Abnormalize Floating Point
AFR Abort Funny Routine
AFVC Add Finagle's Variable Constant
AGB Add GarBage
AI Add Improper(ly)
AIB Attack Innocent Bystander
AMM Answer My Mail
AMM Add Mayo and Mustard
AMS Add Memory to System
ANFSCD And Now For Something Completely Different
AOI Annoy Operator Immediate
AR Advance Rudely
AR Alter Reality
ARN Add and Reset to Nonzero
ARZ Add and Reset to Zero
AS Add Sideways
AT Accumulate Trivia
AWP Argue With Programmer
AWTT Assemble with Tinker Toys
-B-
BA Branch Anywhere
BAC Branch to Alpha Centauri
BAF Blow all Fuses
BAFL Branch and Flush
BAH Branch and Hang
BALC Branch and Link Cheeseburger
BAP Branch and Punt
BAW Bells and Whistles
BB Branch on bug
BBBB Byte Baudy Bit and Branch
BBD Branch on Bastille Day
BBIL Branch on Burned-Out Indicator Light
BBLB Branch on Blinking Light Bulb
BBT Branch on Binary Tree
BBW Branch Both Ways
BCB Burp and Clear Bytes
BCF Branch and Catch Fire
BCF Branch on Chip box Full
BCIL Branch Creating Infinite Loop
BCR Backspace Card Reader
BCU Be Cruel and Unusual
BD Backspace Disk
BD Branch to Data
BDC Break Down and Cry
BDI Branch to Data, Indirect
BDM Branch and Disconnect Memory
BDT Burn Data Tree
BE Branch Everywhere
BEW Branch Either Way
BF Belch Fire
BFF Branch and Form Feed
BFM Be Fruitful and Multiply
BH Branch and Hang
BIR Branch Inside Ranch
BIRM Branch on index register missing
BLC Branch and Loop Continuous
BLI Branch and Loop Infinite
BLM Branch, Like, Maybe
BLMWM Branch, Like, Maybe, Wow, Man
BLP Boot from Line Printer
BLR Branch and Lose Return
BLSH Buy Low, Sell High
BM Branch Maybe
BMI Branch on Missing Index
BMI Branch to Muncee, Immediate
BMP Branch and Make Popcorn
BMR Branch Multiple Registers
BNA Branch to Nonexistant Address
BNCB Branch and Never Come Back
BNR Branch for No Reason
BOB Branch on Bug
BOD Beat on the Disk
BOD Branch on Operator Desperate
BOH Branch on Humidity
BOHP Bribe operator for higher priority
BOI Byte Operator Immediately
BOP Boot OPerator
BOT Branch On Tree
BPB Branch on Program Bug
BPDI Be Polite, Don't Interrupt
BPIM Bury Programmer in Manuals
BPL Branch PLease
BPO Branch on Power Off
BPP Branch & Pull Plug
BR Byte and Run
BRA Branch to Random Address
BRI Branch Indefiniteley
BRO BRanch to Oblivion
BRSS Branch on Sunspot
BS Behave Strangely
BSC Branch on Second Coming
BSI Backup Sewer Immediately
BSM Branch and Scramble Memory
BSO Branch on sleepy operator
BSP Backspace Punch
BSR Branch and Stomp Registers
BSST BackSpace and Stretch Tape
BST Backspace and Stretch Tape
BTD Byte The Dust
BTD Branch on Time of Day
BTJ Branch and Turn Japanese
BTO Branch To Oblivion
BTW Branch on Third Wednesday
BU Branch Unexpectedly
BVS Branch & Veer South
BW Branch on Whim
BWABL Bells, Whistles, and Blinking Lights
BWC Branch When Convenient
BWF Busy - Wait Forever
BWOP BeWilder OPerator
BYDS Beware Your Dark Side
BYTE BYte TEst
-C-
CAC Calling All Cars...
CAC Cash And Carry
CAF Convert ASCII to Farsii
CAI Corrupt Accounting Information
CAIL Crash After I Leave
CAR Cancel Accounts Receivable
CAT Confused And Tired [UNIX]
CB Consult Bozo
CBA Compare and Branch Anyway
CBBR Crash & Blow Boot ROM
CBNC Close, but no Cigar
CBS Clobber BootStrap
CC Call Calvery
CC Compliment Core
CCB Chocolate Chip Byte-mode
CCB Consult Crystal Ball
CCC Crash if Carry Clear
CCCP Conditionally Corrupt Current Process
CCD Clear Core and Dump
CCD Choke Cough and Die
CCR Change Channels at Random
CCS Chinese Character Set
CCWR Change Color of Write Ring
CD Complement Disk
CDC Close Disk Cover
CDC Clear Disk and Crash
CDIOOAZ Calm Down, It's Only Ones and Zeroes
CDS Change Disk Speed
CEMU Close Eyes and Monkey With User Space
CEX Call EXterminator
CF Come From (replaces GOTO)
CFE Call Field Engineer
CFP Change and Forget Password
CFS Corrupt File Structure
CG Convert to Garbage
CH Create Havoc
CHAPMR Chase Pointers Around Machine Room
CHCJ Compare Haig to Christine Jorgensen
CHSE Compare Half-words and Swap if Equal
CIB Change Important Byte
CIC Cash In Chips
CID Compare and Ignore Data
CIMM Create Imaginary Memory Map
CIZ Clear If Zero
CLBR Clobber Register
CLBRI Clobber Register Immediately
CM Circulate Memory
CMD Compare Meaningless Data
CMD CPU Melt Down
CMI Clobber Monitor Immediately
CML Compute Meaning of Life
CMP Create Memory Prosthesis
CMS Click MicroSwitch
CN Compare Nonsensically
CNB Cause Nervous Breakdown
CNS Call Nonexistent Subroutine
COD Crash On Demand
COLB Crash for Operator's Lunch Break
COCS Copy Object Code to Source
COM Clear Operator's Mind
COMF COMe From
CON Call Operator Now
COS Copy Object code to Source file
COWYHU Come Out With Your Hands Up
CP Compliment Programmer
CP%FKM CPU - FlaKeout Mode
CP%WM CPU - Weird Mode
CPB Create Program Bug
CPN Call Programmer Names
CPPR Crumple Printer Paper and Rip
CRASH Continue Running After Stop or Halt
CRB Crash and Burn
CRD Confirm Rumor by Denial
CRM Clear Random Memory
CRM CReate Memory
CRN Convert to Roman Numerals
CRN Compare with Random Number
CRYPT reCuRsive encrYPt Tape mneumonic [UNIX]
CS Crash System
CSL Curse and Swear Loudly
CSN Call Supervisor Names
CSNIO Crash System on Next I/O
CSS Crash Subsidiary Systems
CSU Call Self Unconditional
CTDMR Change Tape Density, Mid Record
CTT Call Time & Temperature
CU Convert to Unary
CUC Cheat Until Caught
CVFL ConVert Floating to Logical
CVFP ConVert FORTRAN to PASCAL
CVG Convert to Garbage
CWAH Create Woman and Hold
CWB Carry With Borrow
CWDC Cut Wires and Drop Core
CWG Chase Wild Goose
CWGK Compare Watt to Genghis Khan
CWIT Compare Watt to Ivan the Terrible
CWM Compare Watt to Mussolini
CWOM Complement Write-only Memory
CZZC Convert Zone to Zip Code
-D-
DA Develop Amnesia
DAB Delete All Bugs
DAO Divide And Overflow
DAP De-select Active Peripheral
DAUF Delete All Useless Files
DB Drop Bits
DBL Desegregate Bus Lines
DBR Debase Register
DBTP Drop Back Ten and Punt
DBZ Divide by Zero
DC Divide and Conquer
DC Degauss Core
DCAD Dump Core And Die
DCD Drop Cards Double
DCGC Dump Confusing Garbage to Console
DCI Disk Crash Immediate
DCON Disable CONsle
DCR Double precision CRash
DCT Drop Cards Triple
DCWPDGD Drink Coffee, Write Program, Debug, Get Drunk
DD Destroy Disk
DD Drop Disk
DDC Dally During Calculations
DDOA Drop Dead On Answer
DDS Delaminate Disk Surface
DDWB Deposit Directly in Wastepaper Basket
DE Destroy Peripherals
DEB Disk Eject Both
DEC Decompile Executable Code
DEI Disk Eject Immediate
DEM Disk Eject Memory
DGT Dispense Gin & Tonic
DHTPL Disk Head Three Point Landing
DIA Develop Ineffective Address
DIE DIsable Everything
DIIL Disable Interrupts and enter Infinite Loop
DIRFO Do It Right For Once
DISC DISmount Cpu
DK Destroy Klingons
DK%WMM Disk Unit - Washing Machine Mode
DKP Disavow Knowledge of Programmer
DLN Don't Look Now...
DLP Drain Literal Pool
DMAG Do MAGic
DMNS Do What I Mean, Not What I Say
DMPE Decide to Major in Phys. Ed.
DMPK Destroy Memory Protect Key
DMZ Divide Memory by Zero
DNPG Do Not Pass Go
DO Divide and Overflow
DOC Drive Operator Crazy
DPCS Decrement Program Counter Secretly
DPMI Declare Programmer Mentally Incompetent
DPN Double Precision No-op
DPR Destroy Program
DPS Disable Power Supply
DR Detach Root
DRAF DRAw Flowchart
DRAM Decrement RAM
DRD DRop Dead
DRI Disable Random Interrupt
DROM Destroy ROM
DRT Disconnect Random Terminal
DS Deadlock System
DSI Do Something Interesting
DSO Disable System Operator
DSP Degrade System Performance
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
DTB Destructively Test Bit
DTC Destroy This Command
DTE Decrement Telephone Extension
DTI Do The Impossible
DTRT Do The Right Thing
DTVFL Destroy Third Variable From Left
DU Dump User
DUD Do Until Dead
DW Destroy World
DWIM Do What I Mean
DWIT Do What I'm Thinking
-E-
EA Enable Anything
EAC Emulate Acoustic Coupler
EAL Enable AC to Logic rack
EAO Enable AC to Operator
EBB Edit and Blank Buffer
EBB Empty Bit Bucket
EBR Erase Before Reading
EBRS Emit Burnt Resistor Smell
EC Eat card
ECL Early Care Lace
ECO Electrocute Computer Operator
ECP Erase Card Punch
ED Eject Disk
ED Execute Data (verrrry useful)
EDD Eat Disk and Die
EDIT Erase Data and Increment Time
EDP Emulate Debugged Program
EDR Execute Destructive Read
EDS Execute Data Segment
EEOIFNO Execute Every Other Instruction From
Now On
EEP Erase Entire Program
EFB Emulate Five-volt Battery
EFD Emulate Frisbee Using Disk Pack
EFD Eject Floppy Disk
EFE Emulate Fatal Error
EHC Emulate Headless Chicken
EIAO Execute In Any Order
EIO Erase I/O page
EIOC Execute Invalid Op-code
EIP Execute Programmer Immeditely
EJD%V EJect Disk with initial velocity V
ELP Enter Loop Permenantly
EM Emulate 407
EM Evacuate Memory
EMM Emulate More Memory
EMPC Emulate Pocket Calculator
EMSE Edit and Mark Something Else
EMSL Entire Memory Shift Left
EMT Electrocute Maintenance Technician
EMW Emulate Matag washer
ENA ENable Anything
ENF Emit Noxious Fumes
ENO Emulate No-Op
EO Electrocute Operator
EOB Execute Operator and Branch
EOI Explode On Interrupt
EOS Erase Operating System
EP Execute Programmer
EPI Execute Programmer Immediately
EPITS Execute Previous Instruction Then Skip
EPL Emulate Phone Line
EPP Eject Printer Paper
EPS Electrostatic Print and Smear
EPS Execute Program Sideways
EPSW Execute Program Status Word
EPT Erase Process Table
EPT Erase Punched Tape
ERIC Eject Random Integrated Circuit
ERM Erase Reserved Memory
EROM Erase Read Only Memory
EROS Erase Read-only Storage
ESB Eject Selectric Ball
ESC Emulate System Crash
ESD Eject Spinning Dish
ESD Eat Shit & Die
ESL Exceed Speed of Light
ESP Enable SPrinkler system
ETI Execute This Instruction
ETM Emulate Trinary Machine
EVC Execute Verbal Commands
EWD Enter Warp Drive
EWM Enter Whimsy Mode
EXI Execute Invalid Operation
EXOP Execute Operator
EXPP Execute Political Prisoner
-F-
FAY Fetch Amulet of Yendor
FB Find Bugs
FC Fry Console
FCJ Feed Cards and Jam
FD Forget Data
FDR Feed Disk Randomly
FERA Forms Eject and Run Away
FFF Form Feed Forever
FLD FLing Disk
FLI Flash Lights Impressively
FM Forget Memory
FMP Finish My Program
FOPC False Out-of-Paper Condition
FPC Feed Paper Continuously
FPT Fire Photon Torpedoes
FRG Fill with Random Garbage
FS Feign Sleep
FSM Fold, Spindle and Mutilate
FSRA Forms Skip and Run Away
-G-
GBB Go to Back of Bus
GCAR Get Correct Answer Regardless
GDP Grin Defiantly at Programmer
GDR Grab Degree and Run
GENT GENerate Thesis
GEW{JO} Go to the End of the World {Jump Off}
GFD Go Forth and Divide
GFM Go Forth and Multiply
GIE Generate Irreversible Error
GLC Generate Lewd Comment
GMC Generate Machine Check
GMCC Generate Machine Check and Cash
GND Guess at Next Digit
GORS GO Real Slow
GREM Generate Random Error Message
GREP Global Ruin, Expiration, and Purgation [UNIX]
GRMC Generate Rubber Machine Check
GS Get Strange
GSB Gulp and Store Bytes
GSI Generate Spurious Interrupts
GSU Geometric Shift Up
GTJ Go To Jail
-H-
HACF Halt And Catch Fire
HAH Halt And Hang
HBW Hang Bus & Wait
HCP Hide Central Processor
HCRS Hang in CRitical Section
HDO Halt and Disable Operator
HDH Hi Dee Ho
HDRW Halt and Display Random Word
HELP Type "No Help Available"
HF Hide File
HGD Halt, Get Drunk
HHB Halt and Hang Bus
HIS Halt in Imposible State
HOO Hide Operator's Output
HRPR Hang up and Ruin Printer Ribbon
HSC Halt on System Crash
HSJ Halt, Skip and Jump
HTC Halt & Toss Cookies
HTS Halt & Throw Sparks
HUAL Halt Until After Lunch
HUP Hang Up Phone
HWP Halt Without Provocation
-I-
IAND Illogical AND
IAE Ignore All Exceptions
IAI Inquire and ignore
IBM Increment and Branch to Muncee
IBP Insert Bug and Proceed
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
IDNOP InDirect No-OP
IDPS Ignore Disk Protect Switch
IEOF Ignore End Of File
IF Invoke Force
IGI Increment Grade Immediately
IGIT Increment Grade Immediately Twice
IHC Initiate Head Crash
II Inquire and Ignore
IIB Ignore Inquiry and Branch
IIC Insert Invisible Characters
IIL Irreversable Infinite Loop
IM Imagine Memory
IMBP Insert Mistake and Blame Programmer
IMP Imitate Monty Python
IMPG IMPress Girlfriend
IMV IMpress Visitors
INCAM INCrement Arbitrary Memory
INI Ignore Next Instruction
INOP Indirect No-OP
INR INstigate Rumor
INW INvalidate Warranty
IOI Ignore Operator's Instruction
IOR Illogical OR
IP Increment and Pray
IPI Ignore Previous Instruction
IPM Ignore Programmer's Mistakes
IPOP Interrupt Processor, Order Pizza
IPS Incinerate Power Supply
IPS Increment Power Supply
IPT Ignite Paper Tape
IRB Invert Record and Branch
IRBI Insert Random Bits Indexed
IRC Insert Random Commands
IRE Insert Random Errors
IRI Ignore Rude Interrupts
IRPF Infinite Recursive Page Fault
ISC Ignore System Crash
ISC Insert Sarcastic Comments
ISC Ignore Supervisor Calls
ISI Increment and Skip on Inifinity
ISP Increment and Skip on Pi
ISTK Invert STacK
ITML Initiate Termites into Macro Library
IU Ignore User(s)
IZ Ignore Zeroes
-J-
JAA Jump Almost Always
JBS Jump and Blow Stack
JCI Jump to Current Instruction
JFM Jump on Full Moon
JHRB Jump to H&R Block
JLP Jump and Lose Pointer
JMAT JuMp on Alternate Thursdays
JN Jump to Nowhere
JNL Jump when programmer is Not Looking
JOM Jump Over Moon
JOP Jump OPerator
JPA Jump when Pizza Arrives
JRAN Jump RANdom
JRCF Jump Relative and Catch Fire
JRGA Jump Relative and Get Arrested
JRL Jump to Random Location
JRSR Jump to Random Subroutine
JSC Jump on System Crash
JSU Jump Self Unconditional
JT Jump if Tuesday
JTT Jump and Tangle Tape
JTZ Jump to Twilight Zone
JWN Jump When Necessary
-K-
KCE Kill Consultant on Error
KEPITU Kill Every Process In The Universe
KP Krunch Paper
KSR Keyboard Shift Right
KUD Kill User's Data
-L-
LAC Lose All Communication
LAGW Load And Go Wrong
LAP Laugh At Program(mer)
LCC Load and Clear Core
LCD Launch Cartridge Disk
LCK Lock Console Keyswitch
LEB Link Edit Backwards
LIA Load Ineffective Address
LMB Lose Message and Branch
LMO Load and Mug Operator
LMYB Logical MaYBe
LN Lose inode Number [UNIX]
LNP Load N digits of Pi
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
LPRTC Load Program counter from Real Time Clock
LR Load Revolver
LRA Load RetroActively
LRD Load Random Data
LSPSW Load and Scramble PSW
LTS Link To Sputnik
LUM LUbricate Memory
LWE Load WhatEver
LWM Load Write-only Memory
-M-
MAB Melt Address Bus
MAN Make Animal Noises
MAZ Multiply Answer by Zero
MBC Make Batch Confetti
MBH Memory Bank Hold-up
MBR Multiply and be Fruitful
MBTD Mount Beatles on Tape Drive
MBTOL Move Bug To Operator's Lunch
MC Move Continuous
MD Move Devious
MDB Move and Drop Bits
MDC Make Disk Crash
MDDHAF Make Disk Drive Hop Across Floor
MFO Mount Female Operator
MLB Memory Left shift and Branch
MLP Make Lousy Program
MLP Multiply and Lose Precision
MLR Move and Lose Record
MMLG Make Me Look Good
MNI Misread Next Instruction
MOG Make Operator Growl
MOP Modify Operator's Personality
MOU MOunt User [causes computer to screw you]
MPLP Make Pretty Light Pattern
MRZ Make Random Zap
MSGD Make Screen Go Dim
MSP Mistake Sign for Parity
MSPI Make Sure Plugged In
MSR Melt Special Register
MST Mount Scotch Tape
MT%HRDV Mag Tape - High speed Rewind and Drop Vaccuum
MTI Make Tape Invalid
MW Malfunction Whenever
MW Multiply Work
MWAG Make Wild-Assed Guess
MWC Move and Wrap Core
MWT Malfunction Without Telling
-N-
NBC Negate By Clearing
NMI Negate Most Integers
NOP Needlessly Omit Pointer
NPC Normalize Program Counter
NTGH Not Tonight, i've Got a Headache
-O-
OCF Open Circular File
OMC Obscene Message to Console
OML Obey Murphy's Laws
OPP Order Pizza for Programmer
OSI Overflow Stack Indefinitely
OTL Out To Lunch
-P-
P$*! Punch Obscenity
PA Punch in ASCII
PAS Print And Smear
PAUD PAUse Dramatically
PAZ Pack Alpha Zone
PBC Print and Break Chain
PBD Print and Break Drum
PBM Pop Bubble Memory
PBPBPBP Place Backup in Plain Brown Paper Bag, Please
PBST Play Batch mode Star Trek
PCI Pleat Cards Immediate
PCR Print and Cut Ribbon
PD Play Dead
PD Punch Disk
PDLD Power Down and Lock Door (to computer room)
PDSK Punch DiSK
PEHC Punch Extra Holes in Cards
PEP Print on Edge of Paper
PFD Punt on Fourth Down
PFE Print Floating Eye [rogue]
PFML Print Four Million Lines
PI Punch Invalid
PIBM Pretend to be an IBM
PIC Print Illegible Characters
PIC Punch Invalid Character
PLSC Perform Light Show on Console
PNIH Place Needle in Haystack
PNRP Print Nasty Replies to Programmer
PO Punch Operator
POCL Punch Out Console Lights
POG Print Only Greek
POPI Punch OPerator Immediately
POPN Punch OPerator's Nose
PPA Print Paper Airplanes
PPL Perform Perpetual Loop
PPP Print Programmer's Picture
PPR Play Punk Rock
PPSW Pack Program Status Word
PSP Print and Shred Paper
PSR Print and Shred Ribbon
PTP Produce Toilet Paper
PVLC Punch Variable Length Card
PWP Print Without Paper
PWS create PoWer Surge
PYS Program Yourself
-Q-
QWYA Quit While Your Ahead
-R-
RA Randomize Answer
RAM Read Ambiguous Memory
RAN Random Opcode [similar to 16-bit what gate]
RASC Read And Shred Card
RAST Read And Shred Tape
RAU Ridicule All Users
RBAO Ring Bell and Annoy Operator
RBG Read Blank Tape
RBLY Restore Back-up from Last Year
RBT Rewind and Break Tape
RC Rewind Core
RCAJ Read Card And Jam
RCB Read Command 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
RCL Rotate Carry Left
RCR Rewind Card Reader
RCRV Randomly Convert to Reverse Video
RCSD Read Card, Scramble Data
RD Reverse Directions
RD Randomize Data
RDA Refuse to Disclose Answer
RDB Run Disk Backwards
RDB Replace Database with Blanks
RDD Reverse Disk Drive
RDDBF Rock Disk Drive Back and Forth
RDEB Read and Drop Even number of Bits
RDF Randomize Directory Filenames
RDI Reverse Drum Immediate
RDR Reverse Disk Rotation
RDS Read SiDeways
RENVR REName Variables Randomly
RET Read and Erase Tape
RF Read Fingerprints
RG Record Garbage
RHO Randomize and Halt if not = to 0
RIC Rotate Illogical thru Carry
RID Read Invalid Data
RIOP Rotate I/O Ports
RIR Read Invalid Record
RIRG Read Inter-record Gap
RJE Return Jump and Explode
RLC Relocate and Lose Core
RLC Reread Last Card
RLC Rotate Left with Carolyn
RLI Rotate Left Indefinitely
RLP Rewind Line Printer
RLP Refill Light Pen
RM Ruin My files
RMI Randomize Memory Immediate
RMT Remove Trap
RMV Remove Memory Virtues
RN Read Noise
RNBS Reflect Next Bus Signal
ROC Randomize Op Codes
ROC Rotate Outward from Center
ROD ROtate Diagonally
ROM Read Operator's Mind
ROO Rub Out Operator
ROOP Run Out Of Paper
ROPF Read Other People's Files
ROS Reject Operating System
ROS Return On Shield
RP Read Printer
RPB Read Print and Blush
RPB Raise Parity Bits
RPBR Reverse Parity and BRanch
RPC Rotate Program Counter
RPM Read Programmer's Mind
RPU Read character and Print Upsidedown
RRC Rotate Random thru Carry
RRR Read Record and Run away
RRR Randomly Rotate Register
RRRL Random Rotate Register Left
RRRR Random Rotate Register Right
RRSGWSSNK Round and Round She Goes, Where
She Stops, Nobody Knows
RRT Record and Rip Tape
RS Random Slew
RSD On Read Error Self-Destruct
RST Rewind and Stretch Tape
RSTOM Read From Store-only Memory
RT Reduce Throughput
RTS Return To Sender
RVAC Return from VACation
RWCR ReWind Card Reader
RWD ReWind Disk
RWF Read Wrong File
-S-
SA Store Anywhere
SAD Search(seek) and Destroy
SAI Skip All Instructions
SAS Sit And Spin
SAS Show Appendix Scar
SBE Swap Bits Erratically
SC Scramble Channels
SC Shred Cards
SCB Spindle Card and Belch
SCCA Short Circuit on Correct Answer
SCD Shuffle and Cut DEC
SCH Slit Cards Horizontal
SCI Shred Cards Immediate
SCM Set for Crash Mode
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
SDD Seek and Destroy Data
SDDB Snap Disk Drive Belt
SDE Solve Differential Equations
SDI Self Destruct Immediately
SDM Search and Destroy Memory
SDR Slam Down Rondo [worst soda ever made]
SEB Stop Eating and Burp
SEOB Set Every Other Bit
SEX Set EXecution register [real on the RCA 1802]
SEX Sign EXtend
SFH Set Flags to Half-mast
SFP Send for Pizza
SFR Send for Reinforcements
SFT Stall For Time
SFTT Strip Form Tractor Teeth
SHAB Shift a Bit
SHABM Shift a Bit More
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
SJV Scramble Jump Vectors
SLP Sharpen Light Pen
SMC Scramble Memory Contents
SMD Spontaneous Memory Dump [classfied data only]
SMR Skip on Meaningless Result
SMS Shred Mylar Surface
SNARF System Normalize and Reset Flags
SNM Show No Mercy
SNO Send Nukes on Overflow
SOAWP SOlve All the World'd Problems
SOB Stew On Brew [a real PDP-11 instruction]
SOD Surrender Or Die !
SOI Screw O'Coin Intentionally (personal one)
SOP Stop and Order Pizza
SOS Sign off, Stupid
SOT Sit on a Tack
SP Scatter Print
SPA Sliding Point Arithmetic
SPD Spin Dry Disc
SPB Simulate Peanut Butter
SPS Set Panel Switches
SPSW Scramble Program Status Word
SQPWYC Sit Quietly and Play With Your Crayons
SRBO Set Random Bits to Ones
SRBZ Set Random Bits to Zeroes
SRC Select Random Channel
SRCC Select Reader and Chew Cards
SRD Switch to Random Density
SRDR Shift to Right Double Ridiculous
SRO Sort with Random Ordering
SROS Store in Read Only Storage
SRR Shift Registers Random
SRSD Seek Record and Scratch Disk
SRSZ Seek Record and Scar Disk
SRTC Stop Real-Time Clock
SRU Signoff Random User
SRZ Subtract and Reset to Zero
SRDR Shift Right Double Ridiculous
SRSD Seek Record and Scar Disk
SRZ Subtract and Reset to Zero
SSB Scramble Status Byte
SSJ Select Stacker and Jam
SSJP Select Stacker and JumP
SSM Solve by Supernatural Means
SSP Seek SPindle
SSP Smoke and SPark
SST Seek and Stretch Tape
ST Set and Test
STA STore Anywhere
STC Slow To a Crawl
STD Stop, Take Drugs
STM STretch Magtape
STM Skip on Third Monday
STO Strangle Tape Operator
STROM Store in Read-only Memory
STPR SToP Rain
STROM STore in Read-Only Memory
STTHB Set Terminal to Three Hundred Baud
SUIQ Subtract User's IQ
SUME SUprise ME
SUP Solve Unsolvable Problem
SUR Screw Up Royally
SUS Stop Until Spring
SUS Subtract Until Senseless
SWAT SWAp Terminals
SWN SWap Nibbles
SWOS Store in Write Only Storage
SWS Sort to Wrong Slots
SWT Select Wrong Terminal
SWU Select Wrong Unit
SWZN Skip Whether Zero or Not
SZD Switch to Zero Density
-T-
TAH Take A Hike
TAI Trap Absurd Inputs
TARC Take Arithmetic Review Course
TBFTG Two Burgers and Fries To Go
TC Transmit Colors (but avoid red)
TDB Transfer and Drop Bits
TDRB Test and Destroy Random Bits
TDS Trash Data Segment
TLNF Teach me a Lesson i'll Never Forget
TLO Turn Indicator Lights Off
TLW Transfer and Lose Way
TN Take a Nap
TOAC Turn Off Air Conditioner
TOG Time Out, Graduate
TOG Take Out Garbage
TOH Take Operator Hostage
TOO Turn On/Off Operator
TOP Trap OPerator
TOS Trash Operating System
TPD Triple Pack Decimal
TPDH Tell Programmer to Do it Him/Herself
TPF Turn Power Off
TPN Turn 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%CN TeleType - Clunk Noise
TT%EKB TeleType - Electrify KeyBoard
TTA Try, Try Again
TTIHLIC Try To Imagine How Little I Care
TTITT Turn 2400 foot Tape Into Two 1200 foot Tapes
TTL Tap Trunk Line
TTL Time To Logoff
TYF Trust Your Feelings
-U-
UA Unload Accumulator
UAI Use Alternate Instrucction set
UAPA(AM) Use all Power Available (And More)
UCB Uncouple CPU and Branch
UCK Unlock Console Keyswitch
UCPUB Uncouple CPU's and Branch
UDR Update and Delete Record
UER Update and Erase Record
UFO Unidentified Flag Operation
ULDA UnLoaD Accumulator
UMR Unlock Machine Room
UNPD UNPlug and Dump
UOP Useless OPeration
UP Understand Program(mer)
UPA Use all Power Available
UPC Understand Program(mer)'s Comments
UPCI Update Card In Place
UPI Undo Previous Instruction (only in EMACS)
URB Update, Resume and Branch
UTF Unwind Tape onto Floor
UTF Use The Force
UUBR Use Undefined Base Register
-V-
VAX Violate All eXecutions
VFE Violate Field Engineer
VFO Violate Female Operator
VMA Violate Maintenance Agreement
VNO Violate Noise Ordinance
VPA Vanishing Point Arithmetic
VVM Vaporize Virtual Memory
-W-
WAD Walk Away in Disgust
WAT WAste Time
WBB Write to the Bit Bucket
WBT Water Binary Tree
WC Waste Core [UNIX]
WCR Write to Card Reader
WDR Warp disk DRive
WED Write and Erase Data
WEMG Write Eighteen Minute Gap
WF Wait Forever
WGPB Write Garbage in Process-control Block
WHFO Wait Until Hell Freezes Over
WHP Wave Hands over Program
WI Write Illegibly
WI Why Immediate
WID Write Invalid Data
WNHR Write New Hit Record
WNR Write Noise Record
WPET Write Past End of Tape
WPM Write Programmer's Mind
WSE Write Stack Everywhere
WSWW Work in Strange and Wonderous Ways
WUPO Wad Up Printer Output
WWLR Write Wrong-Length Record
WWR Write Wrong Record
WSWW Work in Strange and Wondrous Ways
-X-
XIO eXecute Invalid Opcode
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
XSP eXecute Systems Programmer
XVF eXchange Virtue for Fun
-Y-
YAB Yet Another Bug
YASE Yet Another Stupid Error
-Z-
ZAP Zero and Add Packed
ZAR Zero Any Register
ZD Zap Directory
ZEOW Zero Every Other Word
ZPI ZaP Immediate
Sperry (Unisys) 1100/90 Opcodes :
AGB Add GarBage
BBL Branch on Burned out Light
BAH Branch And Hang
BLI Branch and Loop Infinite
BPB Branch on Program Bug
BPO Branch if Power Off
CPB Create Program Bug
CRN Convert to Roman Numerals
DAO Divide And Overflow
ERS Erase Read-only Storage
HCF Halt and Catch Fire
IAD Illigical And
IOR Illogical Or
MDB Move and Drop Bits
MWK Multiply WorK
PAS Print And Smear
RBT Read and Break Tape
RPM Read Programmer's Mind
RRT Record and Rip Tape
RSD Read and Scramble Data
RWD ReWind Disk
TPR Tear PapeR
WED Write and Erase Data
WID Write Invalid Data
XIO Execute Invalid Opcode
XOR Execute OperatoR
XPR Execute ProgrammeR
--
/\ ? ________________
jjo...@topaz.rutgers.edu \ ____ __ fgu |.signature under|
Anything is possible... \ | | / | orywlut- | construction |
========== gfgsdfsdfsd |________________|
_____________________________OO_____O___hfdhksjdhfksjdfs_______||__________||__
-Alan
Stay away from hurricanes for a while.
>-Dale
rik
Terry Conklin
>There was (is) absolutely NO WAY to harm the computer through software.
>I am absolutely positive about the Atari, & Apple. I have heard
>rumors about the Commodore PET possibly having this problem, but
>I don't believe it for a second.
>--
>Brian K. Dore' Internet : b...@pc.usl.edu
I'm afraid you're a bit off here. Historically, there have been several
different machines with which you could destroy hardware through
software. Perhaps the most humorous was the original IBM CGA card,
which would allow you to set really extreme values in the control
registers, sending beyond-legal values to the monitor which would merrily fry.
Terry Conklin
con...@egr.msu.edu
uunet!frith!conklin
The Club (517) 372-3131
Jeff 'Zar' Hildebrand
I *do* know a little about this 'feature' in the Commodore PETs. Apparently
there was a memory location that controlled the clock speed of the processor.
Altering this location was particularly useful for doing high speed screen
updates. The problem was that the clock speed did not simply get bumped up to a
higher rate - instead it continued to increase. If left long enough, the CPU
simply burned up.
Jeff
Gary Duzan
=>From article <30...@nigel.ee.udel.edu>, by gdt...@freezer.it.udel.edu (Gary Duzan):
=>>
=>> =>
=>> =>|"Oh boy, virtual memory! Now I'm gonna make myself a REALLY BIG ram disk!" |
=>> Sounds good to me. The Bullet File System (Amoeba) does something pretty
=>> close to this. It seems to be getting more popular.
=>
=>I have never heard of the Bullet File System. Where can I get a copy. Is
=>it sold by Atari dealers. I don't think my local one has heard of it
=>either. At least it has never been brought up at any of our User Group
=>meetings.
=>
I guess that's what I get for replying to someone's signature. The BFS
has nothing whatsoever to do with Atari. In fact, it would be impossible to
implement without virtual memor and at least 24 bit virtual addresses. You
just don't get that sort of thing with a 6502 (though it would be neat to
implement it on a 65816 (Turbo-816, IIgs.))
The BFS was created for the Amoeba Distributed Operating System at the
Free University in Amsterdam, The Netherlands. It essentially maps entire
files into a virtual memory page table when they are opened. The file
system accesses the file's page table to read the file. I haven't gotten
to read up on the specifics, but that is basically the idea.