lennox@minilove.diag.stratus.com (Craig Scott Lennox) (09/18/90)
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: lennox@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. |
gdtltr@freezer.it.udel.edu (Gary Duzan) (09/18/90)
In article <LENNOX.90Sep18094730@minilove.diag.stratus.com> lennox@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 :-) Gary Duzan Time Lord Third Regeneration -- gdtltr@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_|
lennox@minilove.diag.stratus.com (Craig Scott Lennox) (09/18/90)
In article <30828@nigel.ee.udel.edu> gdtltr@freezer.it.udel.edu (Gary Duzan) writes: In article <LENNOX.90Sep18094730@minilove.diag.stratus.com> lennox@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. -- | flame me at: lennox@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. |
gdtltr@freezer.it.udel.edu (Gary Duzan) (09/18/90)
In article <LENNOX.90Sep18104900@minilove.diag.stratus.com> lennox@minilove.diag.stratus.com (Craig Scott Lennox) writes: =>In article <30828@nigel.ee.udel.edu> gdtltr@freezer.it.udel.edu (Gary Duzan) writes: => => In article <LENNOX.90Sep18094730@minilove.diag.stratus.com> lennox@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. Gary Duzan Time Lord Third Regeneration -- gdtltr@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_|
Ordania-DM@cup.portal.com (Charles K Hughes) (09/19/90)
Craig Lennox asks: >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: lennox@minilove.diag.stratus.com, (Craig Scott Lennox) | Charles_K_Hughes@cup.portal.com
Ordania-DM@cup.portal.com (Charles K Hughes) (09/19/90)
Craig Lennox writes: >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: lennox@minilove.diag.stratus.com, (Craig Scott Lennox) | Charles_K_Hughes@cup.portal.com
csbrod@medusa.informatik.uni-erlangen.de (Claus Brod ) (09/19/90)
lennox@minilove.diag.stratus.com (Craig Scott Lennox) writes: >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) csbrod@medusa.informatik.uni-erlangen.de ----------------------------------------------------------------------
landon@Apple.COM (Landon Dyer) (09/19/90)
>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 (landon@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 (landon@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
dalekim@llama.Ingres.COM (Dale Kim) (09/20/90)
In article <LENNOX.90Sep18094730@minilove.diag.stratus.com> lennox@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? 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
kimes@cbnewsc.att.com (Kit Kimes) (09/21/90)
From article <30842@nigel.ee.udel.edu>, by gdtltr@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. Kit Kimes AT&T Bell Labs Naperville, IL ...!att!iwtsa!kimes
edp367s@monu6.cc.monash.edu.au (Rik Harris) (09/21/90)
dalekim@llama.Ingres.COM (Dale Kim) writes: >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 - edp367s@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.
dac@ukc.ac.uk (David Clear) (09/21/90)
In article <1990Sep19.171649.20159@ingres.Ingres.COM> dalekim@llama.Ingres.COM (Dale Kim) writes: >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 dac@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. <<<
bkd@pc.usl.edu (Dore Brian K) (09/21/90)
dac@ukc.ac.uk (David Clear) writes: >>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 : bkd@pc.usl.edu Programmer /Analyst U.S. Mail : PO Box 42770 Computing Center Lafayette, LA 70504 University of Southwestern LA Telephone : (318) 231-6868
potter@speedway.DAB.GE.COM (Jeff Potter) (09/22/90)
There was an op code on the old Motorola 6800 named HCF (for halt and catch 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 ...potter@ge-dab.ge.com ...mcnc!codas!ge-dab.GE.COM!potter
dac@ukc.ac.uk (David Clear) (09/22/90)
In article <15061@rouge.usl.edu> bkd@pc.usl.edu (Dore Brian K) writes: [ 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). -- % cc life.c | David Clear dac@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. <<<
edp367s@monu6.cc.monash.edu.au (Rik Harris) (09/23/90)
dalekim@llama.Ingres.COM (Dale Kim) writes: >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: peterd@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: <2207@opus.cs.mcgill.ca> Date: 6 Sep 90 17:05:50 GMT References: <ben.2630@epmooch.UUCP> <7951@helios.TAMU.EDU> <1713@cygnus.scol.UUCP> Organization: SOCS, McGill University, Montreal, Canada Lines: 1067 In article <1713@cygnus.scol.UUCP>, davidgu@scol.UUCP (David Gurr) writes: > dcook@cssun.tamu.edu (David A. Cook) writes: > > >In article <ben.2630@epmooch.UUCP> ben@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 -- /\ ? ________________ jjoshua@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 -- Rik Harris - edp367s@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.
conklin@frith.uucp (Terry Conklin) (09/24/90)
In article <15061@rouge.usl.edu> bkd@pc.usl.edu (Dore Brian K) writes: >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 : bkd@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 conklin@egr.msu.edu uunet!frith!conklin The Club (517) 372-3131
gdtltr@freezer.it.udel.edu (Gary Duzan) (09/26/90)
In article <1990Sep20.175834.10283@cbnewsc.att.com> kimes@cbnewsc.att.com (Kit Kimes) writes: =>From article <30842@nigel.ee.udel.edu>, by gdtltr@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. Gary Duzan Time Lord Third Regeneration -- gdtltr@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_|