apocryphal opcode mnemonics,long

308 views
Skip to first unread message

young a t

unread,
Apr 23, 1990, 12:59:46 AM4/23/90
to
Recently an item was posted mentioning some legendary op-codes, including
HCF for "Halt and Catch Fire". The claim was that this was an actual
command on some system c.1975, as was CRN for "Convert to Roman Numerals".
I'm sure both of these were fictitious, as I met them earlier.

CRN is clearly a parody of the IBM 7090's CRQ instruction, the nearest thing
to a Rube Goldberg machine ever constructed. To quote from IBM publication
A22-6528-4 (March 1962), with acronyms expanded for modern readers:

"CRQ -- Convert by Replacement from the MQ
...
This instruction treats the contents of the MQ register as six 6-bit
quantities and replaces the first C of these quantities by values from
tables in core storage.
...
The instruction is executed in the following steps:

1. The address part replaces the address field of the Storage Register.

2. The count field C is placed in the shift register.

3. The contents of the shift register are tested. If the register
contains 0, step 4a follows. If the register is not 0, step 4b follows.

4a. If position 20 of this instruction contains a 1, the address
field of the Storage Register replaces Index Register A and the computer
proceeds to the next sequential instruction. If position 20 contrins a 0,
the computer proceeds directly to the next sequential instruction.

4b. The address bits of the Storage Register are added to the
signed contents of the MQ register to form an address (X). The contents
of X then replace the contents of the Storage Register.

5. The contents of the MQ are shifted left six places. Bits shifted
out of its sign bit are lost. Positions vacated are filled with zeros.

6. The sign and highest 5 bits of the storage register replace the
lowest 6 bits of the MQ.

7. The contents of the shift register are decreased by one, and the
computer returns to step 3."


This wasn't far from converting to Roman numerals. It was intended to do
arithmetic directly on BCD numbers without converting them to binary.
The complexity of this and other instructions led to claims by other
computer manufacturers that their machines executed programs faster because
they had simpler instruction sets. Similar claims are being made today
under the "RISC vs. CISC" argument -- so what else is new?

I first met HCF in a list of "Proposed System/360 Instructions" about 1969
or '70, posted on a wall near a computer at JPL. The list follows:

BH Branch and Hang
IIB Ignore Inquiry and Branch
TDB Transfer and Drop Bits
DO Divide and Overflow
SRZ Subtract and Reset to Zero
PI Punch Invalid [note use of punched cards.]
SSJ Select Stacker and Jam
FSRA Forms Skip and Run Away [predecessor of Launch Paper?]
RASC Read and Shred Card
SRSD Seek Record and Scar Disc [disks were new then.]
BST Backspace and Stretch Tape
RIRG Read Inter-Record Gap
UER Update and Erase Record
EM Emulate 407 [407 = card-deck lister.]
SPSW Scramble Program Status Word
EIOC Execute Invalid Op Code
EROS Erase Read-Only Storage
PBC Print and Break Chain [chain-type line printers were current]
CM Circulate Memory
MLR Move and Lose Record
CRN Convert to Roman Numerals [see above.]
DMPK Destroy Memory Protect Key
DC Divide and Conquer
EPI Execute Programmer Immediate
LCC Load and Clear Core
HCF Halt and Catch Fire


As I recall, the 360's were introduced late, supposedly because IBM had
trouble getting bugs out of the instruction set....


--

A.T.Young, Astronomy Department, San Diego State University, San Diego CA 92182

a...@UCSELX.SDSU.EDU from BITNET

Steve Monson

unread,
Apr 23, 1990, 11:58:37 AM4/23/90
to
In article <1990Apr23....@ucselx.sdsu.edu> a...@ucselx.sdsu.edu (young a t) writes:
>I first met HCF in a list of "Proposed System/360 Instructions" about 1969
>or '70, posted on a wall near a computer at JPL. The list follows:
> [ list deleted ]

Then there was the very useful mnemonic:

BBF Branch on Bitbucket Full


-- mon...@diablo.AMD.COM --- {uunet, cs.utexas.edu!ames}!amdcad!diablo!monson --
Being precocious, I naturally age very fast as well. In fact, at only
twenty-five I was already young at heart.
Peter De Vries (The Prick of Noon)

young a t

unread,
Apr 24, 1990, 6:09:35 PM4/24/90
to
In article <1990Apr24.1...@virtech.uucp> j...@virtech.uucp (Jeremy J. Epstein) writes:
>
> NEWEST DEC OPCODES
>
>BPO Branch on power off

Dan Scott used to have a PWF (=Power Off) macro for FAP on the 704.
It generated the instructions:

Write Tapes Simultaneously
Select Tape Unit 1
Select Tape Unit 2
Select Tape Unit 3
Select Tape Unit 4
.
.
.

About the 4th "select" would overload the system & blow the main circuit
breaker.

>RCR Rewind Card Reader

This was another Dan Scott macro for the 704. The REW instruction had
an address field that was supposed to be a tape unit; but you could put
the address of the card reader there if you wanted to....

Steve Lamont

unread,
Apr 24, 1990, 7:56:25 PM4/24/90
to
In article <1990Apr24....@ucselx.sdsu.edu> a...@ucselx.sdsu.edu (young a t) writes:
>In article <1990Apr24.1...@virtech.uucp> j...@virtech.uucp (Jeremy J. Epstein) writes:
>>RCR Rewind Card Reader
>
>This was another Dan Scott macro for the 704. The REW instruction had
>an address field that was supposed to be a tape unit; but you could put
>the address of the card reader there if you wanted to....

Once upon a time in my rather checkered career, I actually had to *write* such
a thing. It seems we had this wretched old FORTRAN 66 compiler that didn't
know anything about internal reads (of the form

CHARACTER*80 FOO

...

READ ( UNIT = FOO, FMT = ... )

I was working on a card based system where we had to sniff a control field in
a card to determine what type it was and then process the card appropriately.
The formats for the different types, of course, were not even close to being
similar.

I ended up writing a subroutine called REREAD in 370 Assembler (yes, I admit
to having once programmed in IBM Assembler) that went in, munged the DCB or
some such control block, and convinced FORTRAN that it had read a card when it
really hadn't.

Beyond the bizarre...

spl (the p stands for
PSW)

--
Steve Lamont, sciViGuy (919) 248-1120 EMail: s...@ncsc.org
NCSC (The other one), Box 12732, Research Triangle Park, NC 27709
Don't send in no bums. I want deals.
-John Steinbeck, _The Grapes of Wrath_

Paul D. Crowley

unread,
Apr 25, 1990, 7:24:40 AM4/25/90
to
On a BBC Micro the command

>REPEAT: MOTOR ON: MOTOR OFF: UNTIL FALSE

will blow the relay that controls the cassette motor. It goes sort of
Bzzzzzzzzzzzzt! and stops. I've never done it, I've just been told.
--
\/ o\ Paul Crowley ai...@uk.ac.ed.castle :-| Have a day
/\__/ "The whole is the sum of its parts, plus one or more bugs" aimsm@castle

D'Arcy J.M. Cain

unread,
Apr 25, 1990, 10:55:15 AM4/25/90
to
In article <1990Apr23....@ucselx.sdsu.edu> a...@ucselx.sdsu.edu (young a t) writes:
> [...]

>I first met HCF in a list of "Proposed System/360 Instructions" about 1969
>or '70, posted on a wall near a computer at JPL. The list follows:
>
> [list deleted]
I didn't see my favorite:
RPC Randomize Program Counter
I have been able to emulate this on any processor I worked on. :-)

--
D'Arcy J.M. Cain (darcy@druid) | Government:
D'Arcy Cain Consulting | Organized crime with an attitude
West Hill, Ontario, Canada |
(416) 281-6094 |

Jeremy J. Epstein

unread,
Apr 24, 1990, 1:56:33 PM4/24/90
to
In article <1990Apr23....@ucselx.sdsu.edu>, a...@ucselx.sdsu.edu (young a t) writes:
> Recently an item was posted mentioning some legendary op-codes, including
> HCF for "Halt and Catch Fire".

I found the following list of more op-codes in my files.

NEWEST DEC OPCODES

BBI Branch on Burned-out Indicator


BPO Branch on power off

RPB Reverse Parity & Branch
RWT Read/Write While Stretching Tape
SRZ Subtract & Reset to Zero
SSW Scramble Status Word
RCS Read Card & Scramble Data
SSD Stacker Select Disk
RCR Rewind Card Reader
EJD Eject Disk [note that this was before floppies which
were ejected under software control]
BSD Backspace Disk
EIO Execute Invalid Opcode
EXO Execute Operator
ECP Erase Card Punch
RNR Read Noise Record
DMP Destroy Memory Protect Key


MLR Move and Lose Record

DIA Develop Ineffective Address
SCP Scatter Printer


PBC Print and Break Chain

JLP Jump and Lose Pointer
RDI Rewind Disk Immediate
BRL Branch and Leak
SWT Select Wrong Terminal
EXP Exeucte Programmer
DIH Disable Interrupts & Hang
VMA Violate Maintenance Agreement
DFA Disable Fans
EAL Enable AC to Logic Rack
EAO Enable AC to Operator
DIG Disable Gravity
ESP Enable Sprinkler System
AAR Alter at Random
CMD Compare Meaningless Data
ENF Emix Noxious Fumes
ISC Insert Sarcastic Comments
PEHC Punch Extra Holes in Cards
WNAM We Need a Miracle
BRH Branch and Hang
ING Inquire & Ignore
DOV Divide & Overflow
PIC Print Invalid Character
SSJ Select Stacker & Jam
FSR Form Skip & Runaway
WWR Write Wrong Record
RWD Rewind Disk
PCD Punch Disk
FCJ Feed Card & Jam
RTP Reduce Throughput
RST Rewind & Stretch Tape
UCB Uncouple Comm lines & Branch
BRO Branch & Overheat
DIF Disable Fuses
MMF Melt Mainframe
LUM Lubricate Memory
LTS Loop Til Smokes
AIB Attach Innocent Bystandards
DDC Dally During Calculations
FLI Flash Lights Impressively
LAP Laugh at Programmer
SAI Skip All Instructions
RPM Read Programmer's Mind
--
Jeremy Epstein
TRW Systems Division
703-876-8776
j...@virtech.uu.net

David A. Rochberg

unread,
Apr 25, 1990, 4:35:34 PM4/25/90
to
A version of the hacker purity test includes the question

Have you ever "walked" a drive?

I guess this means acessing a file in such a way that r/w head motions
cause the drive enclosure to wobble a bit, but I'm really not sure.
Anyone know ?
-David

young a t

unread,
Apr 24, 1990, 9:17:08 PM4/24/90
to
In article <20...@speedy.mcnc.org> s...@duck.ncsc.org (Steve Lamont) writes:
>In article <1990Apr24....@ucselx.sdsu.edu> a...@ucselx.sdsu.edu (young a t) writes:
>>In article <1990Apr24.1...@virtech.uucp> j...@virtech.uucp (Jeremy J. Epstein) writes:
>>>RCR Rewind Card Reader
>>
(lines omitted...)

>
>Once upon a time in my rather checkered career, I actually had to *write* such
>a thing. It seems we had this wretched old FORTRAN 66 compiler that didn't
>know anything about internal reads (of the form
>
> CHARACTER*80 FOO
>
> ...
>
> READ ( UNIT = FOO, FMT = ... )
>
>I was working on a card based system where we had to sniff a control field in
>a card to determine what type it was and then process the card appropriately.
>The formats for the different types, of course, were not even close to being
>similar.
>
>I ended up writing a subroutine called REREAD in 370 Assembler (yes, I admit
>to having once programmed in IBM Assembler) that went in, munged the DCB or
>some such control block, and convinced FORTRAN that it had read a card when it
>really hadn't.
>
>Beyond the bizarre...
>

Dan Scott also wrote some versions called REREAD for the 704. An early
version traced its calling sequence back into the calling program, then
searched forward for the next reference to the "read card" call, which
it overwrote with NOPs. The next call to IOH or whatever it was that
converted from external to internal formats then re-read the stale input
buffer.

Further beyond the bizarre?

Peter Neilson

unread,
Apr 25, 1990, 10:29:35 AM4/25/90
to
Where I worked long, long ago, we had a PDP-7 running PDP-9 Fortran. And
of course we needed REREAD. If I remember correctly, we simply added an
extra device, an in-core card image. You could read the card (or tape)
unformatted, and write the card image into the core device. Then you could
read the core device as often as need be in whatever manner required until
you got it right, because it would always give you the same "card". Very
handy because we were getting data from all over the world, and you never
really knew beforehand what "standard" (hah!) had been used in writing the
data on tapes and card decks. So much for "Rewind Card Reader".

We never implemented LDE ("Launch Disk Element") because we never had
a disk. We seriously considered something like XFS (Execute Field
Service) because one of the FS reps always did a CM when he came to do
a scheduled PM. (C=Causitive). One time it took three weeks to get
the machine working again after he did a PM.

Here's a few more op codes I think were overlooked:

IPI Interchange PC with Instruction Register
CCK Cache check
CCR Read the one's complement of the card in the reader
ISI Invent stupid instruction at random
SBG Skip over bug

Steve Jay

unread,
Apr 26, 1990, 1:49:49 PM4/26/90
to
dar...@cec1.wustl.edu (David A. Rochberg) writes:

>Have you ever "walked" a drive?

>I guess this means acessing a file in such a way that r/w head motions
>cause the drive enclosure to wobble a bit, but I'm really not sure.
>Anyone know ?

We had model 6603 disks on our CDC computer at the University of Arizona
back around 1970. The drive was actually made by a company called Bryant,
and was larger than a home freezer chest. It weighed close to 1000 pounds,
I think. Then there were the separate cabinets for the hydraulic pumps &
cooling blower.

There were about 16 disks in the cabinet, each about 5 feet in diameter.
The disk spindle spun at 900 RPM. The heads were mounted on a series of
large (2 or 3 foot long) arms, which were moved (in parallel) by a hydraulic
valve. The average access time was about 250 milliseconds, but the
transfer rate was very fast for the day...about a megabyte/second. It
wrote & read 12 heads in parallel. The drive capacity was about 70
million 12 bit words. If I remember right, it cost about $300,000.

Anyway, the disk positioner was heavy enough to have significant momentum.
The disk cabinet would definitely walk accross the floor during heavy
disk activity if it wasn't anchored properly. I remember one of its
supporting legs got bent when it ran into a ventilation register in the
floor. I don't remember anyone ever writing a program specifically
designed to "walk" the drive.

The drive also tended to leak hydraulic fluid...it would leave little
yellow puddles. One time, during maintenance, a hose was left loose
& 5 gallons of hydraulic fluid got dumped under the false floor. We
didn't know about it until someone in the basement complained about
yellow fluid dripping on his desk.

The disk platters made great coffee tables after a head crash.

They don't make 'em like that any more, thank goodness!

Steve Jay
s...@ultra.com ...ames!ultra!shj
Ultra Network Technologies / 101 Dagget Drive / San Jose, CA 95134 / USA
(408) 922-0100 x130 "Home of the 1 Gigabit/Second network"

Kevin Klop

unread,
Apr 26, 1990, 2:10:50 PM4/26/90
to

The easiest way to get a drive to walk is to seek from one edge of the platter
to the other. This can get the drive rocking back and forth in rhythm to the
seeking, and eventually it'll start walking. If you get it right, it'll walk
AWAY from where it's plugged in, and thus eventually unplug itself.

-- Kevin --

aNk1ez

unread,
Apr 26, 1990, 6:34:21 PM4/26/90
to
e: Walking Drives.. Exactly.. Its incredibly nifty, cause they
walk in a random direction.. The bigger the drive, the better...
DEC RP07 drives walk very well.. so do IBM disk pack drives..
infact, if you load a PDP11 chassis with drives and pull the roll-stops..
its easy to sync 3 or 6 of them and make it roll... :->

And i wonder why system managers hate me...

Techs

Robert Stanley

unread,
Apr 26, 1990, 7:37:53 PM4/26/90
to
Well, here's one from my archive. Curiously enough, despite its title,
it shares almost all the revised IBM instruction mnemonics...

Proposed Additions to the PDP-11 Instruction Set

BBW Branch Both Ways
BEW Branch Either Way
BH Branch and Hang
BMR Branch Multiple Registers
BOB Branch On Bug
BOD Beat On Drum [Note: drums were mass-storage devices,
although I don't recall a PDP-11 one]
BOI Byte Operator Immediate
BPO Branch on Power Off


BST Backspace and Stretch Tape

CDS Condense and Destroy System
CLBR Clobber Register
CLBRI Clobber Register Immediate
CM Circulate Memory
CPPR Crumple Printer Paper and Rip


CRN Convert to Roman Numerals

DC Divide and Conquer
DMNS Do what I Mean, Not what I Say


DMPK Destroy Memory Protect Key

DO Divide and Overflow
EIOC Execute Invalid Op-Code
EMPC Emulate Pocket Calculator
EPI Execute Programmer Immediate
EROS Erase Read-Only Storage
EVTH Emulate a VT on a Hazeltine
EXCE Execute Customer Engineer
EXPP Execute a Political Prisoner


FSRA Forms Skip and Run Away

HCF Halt and Catch Fire

IBP Insert Bug and Proceed
IIP Ignore Inquiry and Proceed


LCC Load and Clear Core

MLR Move and Lose Record

PBC Print and Break Chain

PDSK Punch Disk
PI Punch Invalid
POPI Punch Operator Immediate
PVLC Punch Variable Length Card [Ah, what a concept!]
RASC Read And Shred Card
RIRG Read Inter-Record Gap


RPM Read Programmer's Mind

RSD On Read Error Self Destruct
RSTOM Read from Store-Only Memory
RWOC Read Writing On Card


SPSW Scramble Program Status Word

SRSD Seek Record and Scar Disk


SRZ Subtract and Reset to Zero

SSJ Select Stacker and Jam

STROM Store in Read-Only Memory
TDB Transfer and Drop Bit


UER Update and Erase Record

WBT Water Binary Tree
WIRG Write Inter-Record Gap

Now, for a real nostalgia bout, who recalls that marvellous NCR mass
storage system, the CRAM (Card Random Access Memory!)? Yup, it was
real alright.

Robert_S
--
Robert Stanley UUCP: uunet!mitel!sce!cognos!roberts
Cognos, Inc. INET: roberts%cogno...@uunet.uu.net
(Research) Voice: (613) 738-1338 x6115

M Darrin Chaney

unread,
Apr 26, 1990, 8:19:53 PM4/26/90
to
In article <1990Apr25.1...@druid.uucp> da...@druid.UUCP (D'Arcy J.M. Cain) writes:
>In article <1990Apr23....@ucselx.sdsu.edu> a...@ucselx.sdsu.edu (young a t) writes:
>> [...]
>>I first met HCF in a list of "Proposed System/360 Instructions" about 1969
>>or '70, posted on a wall near a computer at JPL. The list follows:
>>
>> [list deleted]
>I didn't see my favorite:
> RPC Randomize Program Counter
>I have been able to emulate this on any processor I worked on. :-)


Reminds me of my favorite VAX instruction BrHQ: Branch to Hell
with Quadword displacement. You're right, it works well on
the 8088 family and TMS9900, and, I've never had to type it :-)

Darrin

mdchaney@iubacs
mdch...@bronze.ucs.indiana.edu
mdch...@rose.ucs.indiana.edu

Michael Ardai

unread,
Apr 27, 1990, 12:12:35 AM4/27/90
to
In article <1990Apr25....@cec1.wustl.edu> dar...@cec2.UUCP (David A. Rochberg) writes:

Not just wobble, but actually move around the room. Remember, these
were physically large drives that resembled washing machines. I have
even heard about competitions among hackers to walk drives across the
machine room or move them closest to a dime on the floor. It must have
really annoyed the first-shift operators :-}

/mike


\|/ Michael L. Ardai ar...@bu-pub.bu.edu
--- ---------------------------------------------------------------
/|\ ...!sun!teda!maven.dnet!ardai (preferred)

Paul Aitken

unread,
Apr 27, 1990, 4:33:20 AM4/27/90
to
In alt.folklore.computers, ai...@castle.ed.ac.uk (Paul D. Crowley) wrote:

>On a BBC Micro the command
>REPEAT: MOTOR ON: MOTOR OFF: UNTIL FALSE
>will blow the relay that controls the cassette motor. It goes sort of
>Bzzzzzzzzzzzzt! and stops. I've never done it, I've just been told.

Well, I've actually done it. The relay in question didn't actually blow
(probably beacuse I realised that I'd have to pay for a new one and stopped it
in time :-) ). The noise is better with a small delay between the MOTOR ON and
MOTOR OFF commands though (which, BTW, should be OSCLI "MOTOR ON" since it's the
OS that controls the relay and not BASIC).

For the more adventurous: an interrupt routine which randomly turns the disk
drive motors on and off (regardless of whether there's a disk there or not),
and a similair routine to grab the disk head, and drag it to either extremity in
rapid succession. This sounds better with a small delay every 10 tracks or so.

What it is to be irresponsible :-)

Disclaimer: I'm only a student.

--
_____
( / ) if ( under_nuc_attack = YES )
/~~~ retaliate();
/ aul

Mark E. Shoulson

unread,
Apr 27, 1990, 12:14:45 AM4/27/90
to

This thread was done a few months ago on this selfsame newsgroup, and the
following *really* long list was posted. Here it is again:

----------------------------------------------
Article 298 of alt.folklore.computers:
Path: cunixf!cunixc!mit-amt!snorkelwacker!usc!rutgers!aramis.rutgers.edu!topaz.rutgers.edu!jjoshua
From: jjo...@topaz.rutgers.edu (Jon Joshua)
Newsgroups: alt.folklore.computers
Subject: Those funny opcodes
Keywords: This belongs in wreck.humor but....
Message-ID: <Dec.12.02.47....@topaz.rutgers.edu>
Date: 12 Dec 89 07:47:08 GMT
Organization: Rutgers Univ., New Brunswick, N.J.
Lines: 1041

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_______||__________||__

-----------------------

~mark
o o o o o o o o o o o o
o o o o o o o
o o o o o o o o o o o N2KOT
Mark E. Shoulson: shou...@cunixf.cc.columbia.edu shou...@cunixc.bitnet

Darren New

unread,
Apr 27, 1990, 1:19:55 PM4/27/90
to
My favorite was always
BNNL - Branch to Never-Nevel Land

Brian L. Stuart

unread,
Apr 27, 1990, 4:18:49 PM4/27/90
to
In article <25...@ariel.unm.edu> cs25...@carina.unm.edu.UUCP (aNk1ez) writes:
>e: Walking Drives.. Exactly.. Its incredibly nifty, cause they
>walk in a random direction.. The bigger the drive, the better...
>DEC RP07 drives walk very well.. so do IBM disk pack drives..
>
>Techs

RK07's do too. When I was an undergrad, we had a PDP11/34 with an RK06
and an RK07 and 6th edition UNIX to run on it (among other OSs). Well
6th edition was pre RK06 and 07 so I decided to learn UNIX systems hacking
by writing a driver for them. To make things managable, I partitioned
those huge (:-) 14MB and 28MB spaces into four logical disks. Well one
day I decided to configure the RK07 so that the root file system was
at one end of the disk and the swap space was at the other.

That was before I understood how much UNIX uses the swap space.

Brian L. Stuart
Department of Computer Science
Purdue University

Paul Campbell

unread,
Apr 27, 1990, 4:50:40 PM4/27/90
to
In article <1990Apr26....@ultra.com> s...@ultra.com (Steve Jay) writes:
>dar...@cec1.wustl.edu (David A. Rochberg) writes:

>The disk platters made great coffee tables after a head crash.

People don't do this much anymore :-) Maybe we should use them for
saucers?

Paul

--
Paul Campbell UUCP: ..!mtxinu!taniwha!paul AppleLink: CAMPBELL.P
"The current plan is to replace the flag with one with alternating vertical
black and white stripes of varying widths - this is thought to better represent
the country's system of government ..."

Per Lindberg

unread,
Apr 27, 1990, 5:53:59 PM4/27/90
to

The Diablo typewheel printer has a rather massive printing head. If
you've ever seen one in action, you probably noticed that the table it
was standing on... rocked.

One of the gedanken pranks discussed at Stacken, the computer club at
KTH (Royal Inst. of Tech. in Stockholm) was a file called DIABLO.VLT
-- the .VLT stands for VALT, or topple in english. It's a file,
which, if you print it on the Diablo, will topple the table by
thrashing the print head back and forth at the table's resonance
frequency. How, you might ask, do you find the table's resonance
frequency? Easy! Just write a program which thrashes the print head
with a frequency slope, until the table falls apart. This will cause
the Diablo to go down with it, pulling out the terminal plug. This is
detected by the program, which then prints out the current value of
the frequency. Piece of cake. Then create a file with those control
sequences.

---

Another similar fight-hardware-with-software story was told when
Stacken visited the IBM printer factory, where they made those
chainsaw... sorry chain printers. Someone had figured out a way to
make *all* the hammers fire simultaneously. Now, the print chain on a
big IBM chain printer is... IBM style - massive, that is. And runs at
a tremendous speed. The standard metaphor for impressing visitors is
picking flowers on the other side of a fence with 30 cm between bars,
from a train going at full speed! The printer was said to jump 2
meters to the left. (And this was before RHPS :-)

"1. Defy authority, 2. Destroy property, 3. Take off people's clothes"
-- Alan Alda's recipe for a box office hit.


--
Per Lindberg (The Mad Programmer) ! __!__
Front Capital Systems ! _____(_)_____ Ceci n'est pas une Piper
Linneg 5, 11447 Stockholm, Sweden ! ! ! !

David Palmer

unread,
Apr 27, 1990, 8:36:18 PM4/27/90
to
I once wrote a copy protection scheme which, when it sensed a deep penetration,
(i.e. on the last anti-hacker barrier) put up a message claiming that
it was about to trash the main floppy disk drive. It then set the track-track
access time to about 40 mS (the maximum allowed by the disk controller)
and SEEK'ed from the first to the last track and back, repeatedly.
It made a noise as if it were slowly grinding up the gear train.

--
David Palmer
pal...@gap.cco.caltech.edu
...rutgers!cit-vax!gap.cco.caltech.edu!palmer
I have the power to cloud men's minds -- or at least my own.

Brian Kantor

unread,
Apr 27, 1990, 10:54:48 AM4/27/90
to
In article <1990Apr25....@cec1.wustl.edu> dar...@cec2.UUCP (David A. Rochberg) writes:

Oh, not just to wobble a bit. It's done by forcing the drive to seek
from track zero to the last track at high speed, then stepping slowly
back to track zero. The positioner lunging in one direction makes the
drive slide forward on the floor just a bit, whilst the slow reverse
seek doesn't undo that at all.

If you run this long enough and the floor is smooth enough, you can get
the drive to slide forward enough that one of the pedestal feet will
finally fall into the hole in the floor where the cables come up, and
the whole mess will suddenly cant over at about 15 degrees or more and
surprise the living hell out of the operators. It'll also probably
destroy the drive, or at least crash a head or two.

What's worse is that this can happen legitimately. Say you've got a bad
sector in cylinder zero, which forwards to the spare sector track out in
cylinder 1023. That's not unusual. But suppose that something
scribbles on the preamble or header on that spare sector; the drive is
going to get a seek error, and as most drives do, step backwards until
it reaches cylinder zero. Since cylinder zero probably has an operating
system overlay on it that will retry lots and lots of times, the bets
need only be layed on how long it will take the drive to walk forward
enough to fall into the cable hole.

Now you know why you should jack the drive up off the wheels with those
screw-down feet. Unless it's under a service contract, of course.
- Brian

kells...@pbs.uucp

unread,
Apr 28, 1990, 2:46:08 PM4/28/90
to
In article <17...@nigel.udel.EDU>, n...@udel.EDU (Darren New) writes:
> My favorite was always
> BNNL - Branch to Never-Nevel Land

Back when our VAX system was spelled PDP-11, the Director of Computer Services
issued a list of mnemonics that he was planning to implement. Though I can't
remember most of them, the one that I was most in favor of was

RWE Read Wrong and Erase

This is obviously an instruction that has been installed on the computers of
some of my creditors, judging from the answers I get when inquiring about
bills!

jim frost

unread,
Apr 28, 1990, 6:52:18 PM4/28/90
to
g...@mentor.cc.purdue.edu (Brian L. Stuart) writes:
>Well one
>day I decided to configure the RK07 so that the root file system was
>at one end of the disk and the swap space was at the other.

>That was before I understood how much UNIX uses the swap space.

...and the root partition :-).

jim frost
saber software
ji...@saber.com

Bernie Cosell

unread,
Apr 29, 1990, 11:09:59 AM4/29/90
to
pai...@cs.strath.ac.uk (Paul Aitken) writes:

}In alt.folklore.computers, ai...@castle.ed.ac.uk (Paul D. Crowley) wrote:

}>On a BBC Micro the command
}>REPEAT: MOTOR ON: MOTOR OFF: UNTIL FALSE
}>will blow the relay that controls the cassette motor. It goes sort of
}>Bzzzzzzzzzzzzt! and stops. I've never done it, I've just been told.

}Well, I've actually done it. The relay in question didn't actually blow
}(probably beacuse I realised that I'd have to pay for a new one and stopped it
}in time :-) ). The noise is better with a small delay between the MOTOR ON and
}MOTOR OFF commands though (which, BTW, should be OSCLI "MOTOR ON" since it's the
}OS that controls the relay and not BASIC).

So did someone write a program to play music on the relay?

/B\

Robert E. Seastrom

unread,
Apr 29, 1990, 7:25:42 PM4/29/90
to
In article <12...@front.se> p...@front.se (Per Lindberg) writes:
>
>The Diablo typewheel printer has a rather massive printing head. If
>you've ever seen one in action, you probably noticed that the table it
>was standing on... rocked.
>
>One of the gedanken pranks discussed at Stacken, the computer club at
>KTH (Royal Inst. of Tech. in Stockholm) was a file called DIABLO.VLT
>-- the .VLT stands for VALT, or topple in english. It's a file,
>which, if you print it on the Diablo, will topple the table by
>thrashing the print head back and forth at the table's resonance
>frequency.

Back when I worked for a civil engineering firm, I noted that an
HP-7596 Draftmaster I plotter would move at a different speed,
depending on the length of its seek. This would yield a kind of
ephemeral 'music' while someone was plotting out a minor subdivision
plan or some such. Has anybody done the research to be able to get an
HP-7596 to play real music?

--
Internet: r...@eddie.mit.edu | Copyright: Protecting your right to
Bitnet: RS@SESTAK | copy software. ---RMS
X.25: PSI%0240200101905::KICKI::RS |

John Kallen

unread,
Apr 29, 1990, 12:39:41 PM4/29/90
to
In article <55...@bbn.COM> cos...@bbn.com (Bernie Cosell) writes:

>pai...@cs.strath.ac.uk (Paul Aitken) writes:
>
>So did someone write a program to play music on the relay?
>
> /B\

A popular way of getting the good ol'e Trash-80 to generate sound was
to wiggle the output port to the cassette player on and off. From
BASIC, it was too slow: you'd get a 100 Hz sound at best. I typed in
a FigFORTH interpreter and one of the first things I did was to try
out the sound capabilities of the language. I was very impressed by
the results: I could toggle the relay so fast it actually couldn't
keep up with the OUT 255,4 commands... (then again, I was a very
impressionable pre-teen :-)

Of course, advanced Trash-80 owners had an EXTERNAL AMP :-) so that
the beautiful monophonal monotimbral square waves could be heard (one
would toggle two other bits of port 255, not the relay.) Right before I
retired my Trash I heard of somebody who had managed to emulate the
sound chip on the CBM-64 (which was the best available in 1985) with
software. Anyone else know about this or was it only a rumor?
_______________________________________________________________________________
| | | | |\ | | /|\ | John Kallen The above is a figment of your
| |\ \|/ \| * |/ | |/| | | PoBox 11215 overworked imagination. Take 2
| |\ /|\ |\ * |\ | | | | Stanford CA 94309 aspirin and call a doctor.
_|_|___|___|____|_\|___|__|__|_j...@neon.stanford.edu___________________________

Phil Gustafson

unread,
Apr 29, 1990, 10:30:45 PM4/29/90
to
In article <1990Apr29....@eddie.mit.edu> r...@eddie.MIT.EDU (Robert E. Seastrom) writes:
>
>Back when I worked for a civil engineering firm, I noted that an
>HP-7596 Draftmaster I plotter would move at a different speed,
>depending on the length of its seek. This would yield a kind of
>ephemeral 'music' while someone was plotting out a minor subdivision
>plan or some such. Has anybody done the research to be able to get an
>HP-7596 to play real music?

Not an HP Draftmaster. But a friend of mine wrote a program for a DG
Nova and Tektronix screen-memory terminal that used bell characters to
make tones controlled by the keyboard. Its features included tremulant
and automatic arpeggios. The program was called "piano" and may still
exist on some Finnigan Instruments GC/MS systems. It wound up being
shipped as standard software.

phil

------------------------------------------------------------------------------
Opinions outside attributed quotations are mine alone.
Satirical material may not be specifically labeled as such.
------------------------------------------------------------------------------


--
| ph...@zorch.SF-Bay.ORG | Phil Gustafson
| (ames|pyramid|vsi1)!zorch!phil | UNIX/Graphics Consultant
i | | 1550 Martin Ave., San Jose CA 95126
| | 408/286-1749

Jack Adams

unread,
Apr 30, 1990, 11:15:16 PM4/30/90
to
>So did someone write a program to play music on the relay?
>
> /B\

While in high school one of the students got an NCR Century 50 ( 8k of real
core) to play Aquarious on a radio sitting on top of a band printer. I think
he sent a series of non-printable characters to create the different sounds.

Jack Adams.

Henry Spencer

unread,
Apr 30, 1990, 1:47:55 PM4/30/90
to
A friend of mine once noticed that the Calcomp plotter on an IBM mainframe
had separate bits for left, right, forward, backward, pen up, and pen down.
Normally, of course, the software generated command words that only had one
bit on each axis turned on. He tried turning them all on. The plotter sat
there, motionless, making a horrible grinding noise...
--
If OSI is the answer, what is | Henry Spencer at U of Toronto Zoology
the question?? -Rolf Nordhagen| uunet!attcan!utzoo!henry he...@zoo.toronto.edu

Andrew MacRae

unread,
Apr 30, 1990, 3:27:43 PM4/30/90
to
In alt.folklore.computers, ai...@castle.ed.ac.uk (Paul D. Crowley) wrote:
>On a BBC Micro the command
>REPEAT: MOTOR ON: MOTOR OFF: UNTIL FALSE
>will blow the relay that controls the cassette motor. It goes sort of
>Bzzzzzzzzzzzzt! and stops. I've never done it, I've just been told.

Back in the 'glory days' of the Radio Shack TRS-80 Model One, this was an
often used method to generate sound. The TRS-80 used a reed relay switch
and if you kept it flipping open and closed fast enough you were bound
to heat it to the point that it would stick fast in one position. The
magazines back then often ran articles on how to un-stick your cassette
port relay.

Stephen Kelley

unread,
Apr 30, 1990, 3:40:40 PM4/30/90
to
In article <1990Apr30....@utzoo.uucp> he...@utzoo.uucp (Henry Spencer) writes:
>
>All-holes-punched cards are generally awfully hard on card equipment.
>--

Along these lines, a story from a class I took long long ago (1971).

As the lecturer related it, Honeywell, back even longer ago, had tried to
compete with IBM by inventing a card code that was denser, that is, could
put more information on a standard card. They were very happy with it,
and spent a large number of dollars developing prototype equipment to
test it. Of course, putting more information on a card meant punching
more holes in it, and what they learned from their expensive prototype
system is that a card with a lot of holes is not very rigid anymore, and
promptly jams the reader.

Steve Kelley kel...@flowcyt.ecn.purdue.edu

Purdue University Cytometry Laboratories

Simon E Spero

unread,
Apr 30, 1990, 8:20:20 AM4/30/90
to

[Cassette motor music]

On the subject of BBC computers and music; nobody has yet factored
in that most wonderous of networking systems, Ethernet. This system had
the wonderful facility of allowing any station to read and write arbitary
segments of the memory map any other station, unless that station
had selected software protection. Since the default state was off, people
decided to take advantage of this security enhancing feature. Two programs
would be written to produce 3 parts of a six voice tune each. These programs
would then be sent to the two stations to the left and right of the victim, and
then executed simultaneously. As the stereo sound floated around him, his
own cassette motor would start adding some precussion. The effects were,
interesting.

--
------------------------------------------------------------------------------
zma...@uk.ac.ic.doc | sispero%c...@specialix.co.uk | ..!ukc!slxsys!cix!sispero
------------------------------------------------------------------------------
Can programming be liberated from the Von Neumann style? No FP, No Comment.
"The GNU Manifesto refers to all Software, not just Editors" | (I'm the FSF)

Henry Spencer

unread,
Apr 30, 1990, 1:45:52 PM4/30/90
to
In article <12...@front.se> p...@front.se (Per Lindberg) writes:
>Another similar fight-hardware-with-software story was told when
>Stacken visited the IBM printer factory, where they made those
>chainsaw... sorry chain printers. Someone had figured out a way to
>make *all* the hammers fire simultaneously...

The paleoelectronic version of this :-) is what is said to have happened if
you fed an all-holes-punched card through a high-speed card duplicator. This
was a gadget that punched all the holes at once, not one column at a time.
Normally it went "chunk! chunk! chunk! chunk!" as it ran. Slip a lace-
curtain card into a deck, and "chunk! chunk! !!**WHAM**!! chunk! chunk!",
with the floor shaking at the obvious time. I never saw it myself, but
people who did say it was most impressive.

All-holes-punched cards are generally awfully hard on card equipment.
--

Mike Butts

unread,
Apr 30, 1990, 3:14:22 PM4/30/90
to
The Floating Point Systems FPS-164 is(was) a 64-bit minisupercomputer circa
1981, with 64-bit multi-field instructions, allowing several operations to be
executed in one processor cycle. (Nowadays, of course, that's 'superscalar',
and it's the latest brilliant new development.... ;-)

The FPS-164's main memory was built with 64K dynamic RAMs, which require
regular refresh cycles. The instruction set includes a supervisor-mode refresh
instruction RFSH, which causes all memory boards to execute a refresh cycle.
RFSH allows memory refresh to be synchronized with a diagnostic scope loop, for
hardware debug purposes.

Well, you could code the following machine instruction: "RFSH; JMP ." This
1-cycle endless loop has the effect of causing a memory refresh operation every
cycle. Since memory refresh cycles take more system power than normal cycles
(they involve ALL chips, not just the addressed ones), the effect of
"RFSH; JMP ." was to overload the memory power supplies. The power controller
would sense this and shut down the machine, bringing up lots of red lights on
the panel. It was particularly diabolical since loss of memory power would
drop memory contents, leaving no trace of what caused the shutdown.

Later the machine was ECO'd to inhibit a RFSH if one had been executed too
recently.
--
Michael Butts, Research Engineer KC7IT 503-626-1302(fax:1282)
Mentor Graphics Corporation, 8500 SW Creekside Place, Beaverton, Oregon 97005
!{ogicse,sequent,tessi,apollo}!mntgfx!mbutts mbu...@pdx.MENTOR.COM
Any opinions are my own, and aren't necessarily shared by Mentor Graphics Corp.

G.J.Cole

unread,
May 1, 1990, 12:58:33 PM5/1/90
to

I once read that you could do a really nasty thing to some of the first
CBM PET 2001s. A certain POKE would stop the electron beam and apparently
destroy the monitor. I had the POKE and I had access to a 2001, but I
daren't try it, so I can't say for sure whether it worked or not. Anybody
out there know more?

Graham

sys...@iowasp.physics.uiowa.edu

unread,
May 1, 1990, 10:28:09 AM5/1/90
to
Organization: Department of Physics and Astronomy, University of Iowa
Lines: 13

In article <1990Apr30....@utzoo.uucp>, he...@utzoo.uucp (Henry Spencer) writes:
> A friend of mine once noticed that the Calcomp plotter on an IBM mainframe

We still have some of these old dog's on our 11/780 here. Currently
they are controlled by a uC that hangs off of a serial port on the VAX.
Control signals to the plotter is via six wires, pen up/down, pen
left/right and drum fwd/back. They get used occasionally when someone
wants a long plot and doesn't want to fiddle with the newer fast
plotters.
Anyone remember the old 835 microfilm plotter that CalComp made
about that same time???

Willy

Douglas W. Jones,201H MLH,3193350740,3193382879

unread,
May 1, 1990, 4:06:45 PM5/1/90
to
From article <14...@sys.uea.ac.uk>, by cmp...@sys.uea.ac.uk (G.J.Cole):

>
> I once read that you could do a really nasty thing to some of the first
> CBM PET 2001s. A certain POKE would stop the electron beam and apparently
> destroy the monitor...
>
This is true of a fair number of workstations and personal computers on the
market today. I had an HP 9836 on my desk for a few years where the manual
for /dev/crt was quite explicit, warning that fiddling with certain areas
of the memory region that you could map with a special system call could
destroy the monitor.

The reason is simple, many modern systems use programmable DMA video
interfaces; these have software settable parameters for such things as the
number of pixels per scan line, the number of scan lines per screen, the
length of the horizontal and vertical synch pulses, and the lengths of the
front and back porches on each synch pulse (those are the correct technical
terms).

Given this, the other key piece of explanatory material is that most video
monitors generate their high voltage with a transformer in the horizongal
scan circuit. This runs at 16Khz in (north american) standard video, but
at higher frequencies in some high resolution video schemes. Raising the
frequency (for example, by scanning fewer than the expected number of
pixels per line) can raise the output voltage, potentially blowing the
diode that delivers high voltage DC to the cathode in the picture tube.
Changing the frequency could also overload some of the drive transistors in
the horizontal circuit, blowing them.

I wouldn't expect to be able to make a video monitor explode doing this,
but overheating the drive transistors might make a bit of acrid smoke as the
screen goes blank.
Doug Jones
jo...@herky.cs.uiowa.edu

Bruce Walker

unread,
May 1, 1990, 7:31:54 AM5/1/90
to
In the early 80's, I was developing daisy wheel printer electronics at AES Data.
The designer of a daisy wheel printer has to ensure that the daisy wheel comes
to rest before the hammer is energized. Of course, a fairly common failure
mode (software bugs usually) was to have the hammer fire while the wheel was
at maximum velocity.

We dubbed this the "defoliate daisy" instruction.

--
Bruce Walker ...uunet!utai!lsuc!isgtec!bmw b...@isgtec.uucp
"Remember Rule Number 79: When the tough get going, the weak get screwed."
ISG Technologies Inc. 3030 Orlando Dr. Mississauga. Ont. Can. L4V 1S8

Stephen Thomas

unread,
May 2, 1990, 7:16:35 AM5/2/90
to
In article <91...@mbf.UUCP> ja...@mbf.UUCP (Jack Adams) writes:
>While in high school one of the students got an NCR Century 50 ( 8k of real
>core) to play Aquarious on a radio sitting on top of a band printer. I think
>he sent a series of non-printable characters to create the different sounds.
>
>Jack Adams.

When I was at North Staffs Polytechnic, we had a lab full of BBC's. One
trick that I heard about was when someone loaded a software speech synthesiser
into the machine, then wrote a program that waited until the evening before
uttering the words

"When it gets late, I like to sit and talk to myself"

The machine, of course, looked as though it had just been switched on, so
nobody expected it. Apparently it caused quite a stir among those who
were quietly working on the other machines.

Music on the BBC was fun to play with. I wrote a system that allowed you
to code music in a description language, which would then be compiled into
a program which would play the music under interrupt control. Since most
of the machines in the lab were networked, we had a demo where each station
would load the program from the fileserver, and then wait for a signal from
a machine designated as the console. Then they would play this music. Of
course, the signal was broadcast to all stations, so all the machines would
start playing simultaneously, and rather loudly. What was interesting was
that there was some propagation delay in the network, so the stations
were not quite in synch - it caused an interesting delayed echo effect that
made the lab seem larger than it was.

After the first demo, the lab technicians turned down the volume on all the
machines :-).

Actually, we had to take one of the machines out of the demo, because it
seemed to like it too much. For no apparent reason, at unpredictable times,
(but when the demo was in "stand-by" mode) it would reset itself, log itself
onto the network, load the music program, and attempt to play it. All it
did, however, was make a horrible series of beeps ...

I am not kidding you, by the way.

Stephen
--
Never give | Stephen Thomas
fate an | JANET: sp...@ukc.ac.uk
even chance | Telephone: +44 (0)227 764000 ext 3824
| Snail: Computing Lab, University of Kent at Canterbury, UK.

Steve Lamont

unread,
May 2, 1990, 8:53:59 AM5/2/90
to
In article <33...@baird.cs.strath.ac.uk> pai...@cs.strath.ac.uk writes:
> if ( under_nuc_attack = YES )
> retaliate();

... yet another reason to be dubious about SDI... :-)

spl (the p stands for
putting my fingers in
my ears and waiting
for the kaboom.)
--
Steve Lamont, sciViGuy (919) 248-1120 EMail: s...@ncsc.org
NCSC (The other one), Box 12732, Research Triangle Park, NC 27709
Don't send in no bums. I want deals.
-John Steinbeck, _The Grapes of Wrath_

Risto Lankinen

unread,
May 3, 1990, 3:49:27 AM5/3/90
to
Hi!

Back then when me and a couple of fellow students were younger we had a
speech synthesizer for the Commodore 64 (S.A.M. was the synth called). We
preprogrammed a couple of phrases in a 'synth voice' so that they could
be triggered by pressing only one key duirng a conversation. Then we call-
ed (mostly people we knew, though) by telephone having a dialog sort of
this:

[C64] "Hello, this is the automatic telephone *CALLER* of Helsinki area
telephone company." (at this point we waited the opposite end to
answer and then manually triggered the following) "We are testing
this new equipment and would like your co-operation. Please spell
or clearly pronounce your name ... " etc etc

The conversation was, of course held in Finnish so that the jokees would not
become suspicious. I'm still wondering whether the HTC ever sent the towels
we'd promised for co-operation or whether people ever called 'back' to them
to ask for it by the time we had already found something less radical to
invent. Fun it was, anyway.

Disclaimer: In order to avoid legal consequences, it is stated that the event
described in this story may or may not have actually happened, and that no
detail of the story can be assumed true or false.

terveisin: Risto Lankinen

--
Risto Lankinen / product specialist ***************************************
Nokia Data Systems, Technology Dept * 2 2 *
THIS SPACE INTENTIONALLY LEFT BLANK * 2 -1 is PRIME! Now working on 2 +1 *
replies: ri...@yj.data.nokia.fi ***************************************

Paul Aitken

unread,
May 3, 1990, 7:44:44 AM5/3/90
to
In alt.folklore.computers, s...@duck.ncsc.org (Steve Lamont) wrote:

>In article <33...@baird.cs.strath.ac.uk> pai...@cs.strath.ac.uk writes:
>> if ( under_nuc_attack = YES )
>> retaliate();
>
>... yet another reason to be dubious about SDI... :-)


You'd be surprised at how *few* people seem to have noticed that :-(

BTW, I'm a student, and have nothing to do with work on SDI.


--
_____
( / )
/~~~ This is the University of Strathclyde, Glasgow, Scotland.
/ aul (Glasgow is the European City of Culture, 1990.)

M Darrin Chaney

unread,
May 3, 1990, 8:58:46 PM5/3/90
to
In article <6...@tuura.UUCP> ri...@tuura.UUCP (Risto Lankinen) writes:
>Hi!
>
>Back then when me and a couple of fellow students were younger we had a
>speech synthesizer for the Commodore 64 (S.A.M. was the synth called). We
>preprogrammed a couple of phrases in a 'synth voice' so that they could
>be triggered by pressing only one key duirng a conversation. Then we call-
>ed (mostly people we knew, though)

I did this with the good old TI-99 and a voice synthesizer. It had a
more realistic sounding voice, and was perfect for the occasion. I
programmed about 30 phrases into the computer that could be spoken
with the touch of a button. Whenever a person would call, I'd hold
the phone to the TV speaker and listen to them, deciding what to have
the "automated home computer phone answering system" to say next.
It's amazing how people will trust technology, in the days when we
didn't even have any speech recognition.

Darrin

mdchaney@iubacs
mdch...@bronze.ucs.indiana.edu
mdch...@rose.ucs.indiana.edu

pir...@cc.helsinki.fi

unread,
May 10, 1990, 7:53:49 AM5/10/90
to
In article <1990Apr29.1...@Neon.Stanford.EDU>, j...@Neon.Stanford.EDU (John Kallen) writes:
> A popular way of getting the good ol'e Trash-80 to generate sound was
> to wiggle the output port to the cassette player on and off.
> ...

> Of course, advanced Trash-80 owners had an EXTERNAL AMP :-) so that
> the beautiful monophonal monotimbral square waves could be heard (one
> would toggle two other bits of port 255, not the relay.)
The cassette player would function as an external amp, if you put the
sound jack in the RADIO input, and pushed RECORD. The amplification was
not much, but considering the quality of the sound, that was all to the
best.

At our school, we had, for some strange reason, the Technical Manual,
where we learned that the sound output could actually be set to three
different voltage levels. I and a friend wrote an sound program that
used three levels on low frequencies and two on high frequencies; this
made an audible difference. Of course, even with an assembler driver
loop, the frequency precision was awful: a performance of Smoke Gets In
Your Eyes would set people laughing.

Another fun part of the Trash was the ingenious memory-mapped keyboard
electronics: The address lines and the data lines crossed in separate
layers under the keys, when you pressed a key it shorted the address
line to the data line! This could be used for funny effects, like
pressing three keys to generate a fourth... Why don't they make funny
computers anymore?


Pekka P. Pirinen
University of Helsinki pir...@cc.helsinki.fi pir...@finuh.bitnet
Believe It Or Not:
I learned BASIC on a Trash-80, and survived to become a programmer!

Mark E. Shoulson

unread,
May 10, 1990, 1:06:23 PM5/10/90
to
In article <2461.2...@cc.helsinki.fi> pir...@cc.helsinki.fi writes:
>Another fun part of the Trash was the ingenious memory-mapped keyboard
>electronics: The address lines and the data lines crossed in separate
>layers under the keys, when you pressed a key it shorted the address
>line to the data line! This could be used for funny effects, like
>pressing three keys to generate a fourth... Why don't they make funny
>computers anymore?

So that's how they did it! Anyone remember, I think it was NEWDOS/80? You
could hit three keys (I think d,f,g) and it would shoot you into a sort of
"mini-dos"--I guess a poor-man's shell escape. Then there was 1,2,3
together to get into debug mode...All these little weirdnesses I was too
inexperienced to make sense of!

>Pekka P. Pirinen
>University of Helsinki pir...@cc.helsinki.fi pir...@finuh.bitnet
>Believe It Or Not:
> I learned BASIC on a Trash-80, and survived to become a programmer!

~mark
I learned BASIC on a Trash-80 -- and word processing, and even some APL,
and I can still program.

o o o o o o o o o o o o
o o o o o o o
o o o o o o o o o o o N2KOT
Mark E. Shoulson: shou...@cunixf.cc.columbia.edu shou...@cunixc.bitnet

Jason William Fuller

unread,
May 11, 1990, 11:08:34 PM5/11/90
to

In article <1990Apr29.1...@Neon.Stanford.EDU>, j...@Neon.Stanford.EDU (John Kallen) writes:
> A popular way of getting the good ol'e Trash-80 to generate sound was
> to wiggle the output port to the cassette player on and off.
> ...
> Of course, advanced Trash-80 owners had an EXTERNAL AMP :-) so that
> the beautiful monophonal monotimbral square waves could be heard (one
> would toggle two other bits of port 255, not the relay.)

Entire music programs were built around this little feature.
One program even got the thing to say a word.

The biggest joke in TRS-80 land was any attempt at copy-protection.
All you had to do was put the cassette in a normal two-tape cassette deck
and press DUB.


--
-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

jwfu...@Phoenix.Princeton.Edu

Jim Stichnoth

unread,
May 12, 1990, 4:06:24 PM5/12/90
to
In article <16...@phoenix.Princeton.EDU>, jwfu...@phoenix.Princeton.EDU

(Jason William Fuller) writes:
|>
|>The biggest joke in TRS-80 land was any attempt at copy-protection.
|>All you had to do was put the cassette in a normal two-tape cassette deck
|>and press DUB.

TRSDOS had a slightly better copy protection scheme for floppies. On a
Model III, the backup routine would copy the entire disk, and then go back
and copy track 17 (the directory track). While copying the directory track,
it would determine which files were protected and remove their directory
entries.

Well, it turns out that you could do a backup once, just to get all the data
on the other tracks copied, and then start another backup. After the second
backup finished copying track 17, you could just reboot the machine. Presto!
Your disk is copied! The backup program didn't bother to modify the directory
the first time around!

This little trick even worked for the infamous Zork protection. I never did
figure out Zork's protection scheme for the Trash-80. Does anyone know how
this was done?

(Oh, and speaking of Zork, does anyone know how to solidify the rainbow in
Zork I? I was told there is a pot of gold there. That is the one thing I
was never able to solve.)

------
Jim Stichnoth
stic...@brahms.llnl.gov

Tim Steele

unread,
May 14, 1990, 6:30:56 AM5/14/90
to
I had a Model I, then a III, then a IV... quite rare in the UK, I
think!

I never came across that backup wrinkle... very nice. Instead, I
disassembled the whole of TRSDOS... very interesting. That DOS was
years ahead of its time, really...

Unfortunately, I once put together a protection scheme based on the
backup count. If it found the count down to zero, the application
would erase the directory hash table - a very effective way of making
the floppy useless. Of course, the only person who got bitten was
me...

Tim
--

tj...@tadtec.uucp ..!uunet!mcvax!ukc!tadtec!tjfs
Tadpole Technology plc, Titan House, Castle Park, CAMBRIDGE, CB3 0AY, UK
Phone: +44-223-461000 Fax: +44-223-460727 Telex: 817316 TADTEC G

Philip J Stephens

unread,
May 15, 1990, 3:45:15 AM5/15/90
to
In article <58...@lll-winken.LLNL.GOV>, stic...@brahms.llnl.gov (Jim Stichnoth) writes:
>
> (Oh, and speaking of Zork, does anyone know how to solidify the rainbow in
> Zork I? I was told there is a pot of gold there. That is the one thing I
> was never able to solve.)

*** SPOILER WARNING ***

I'm not surprised you couldn't solve it; it doesn't seem to have any clues
related to it!

All you have to do is take the sceptre found in the coffin, walk up to the
view of the rainbow, and raise the sceptre into the air!

How did I solve it? Well, I said to myself: "I wonder what would happen if
I raised the sceptre into the air? It seems to be the sort of thing you'd
do with a sceptre whilst standing on top of a cliff. At least, I can't think
of anything else to do with it."

Honest!

The game will tell you that "I think the clue was <such-and-such>", but I'll
be buggered if it makes any sense to me.

</\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\></\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\>
< Philip J. Stephens >< "Many views yield the truth." >
< Hons. student, Computer Science >< "Therefore, be not alone." >
< La Trobe University, Melbourne >< - Prime Song of the viggies >
<\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/><\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/>

Karl Denninger

unread,
May 15, 1990, 3:47:59 PM5/15/90
to
In article <TJFS.90Ma...@tadtec.uucp> tj...@tadtec.uucp (Tim Steele) writes:
>I had a Model I, then a III, then a IV... quite rare in the UK, I
>think!
>
>I never came across that backup wrinkle... very nice. Instead, I
>disassembled the whole of TRSDOS... very interesting. That DOS was
>years ahead of its time, really...
>
>Unfortunately, I once put together a protection scheme based on the
>backup count. If it found the count down to zero, the application
>would erase the directory hash table - a very effective way of making
>the floppy useless. Of course, the only person who got bitten was
>me...

Yep. There are a number of things that few know about the infamous TRS-80,
especially the Models III and IV.

Like that TRSDOS 1.3 (the first "working" TRSDOS) could be coaxed into
destroying files -- by doing some rather normal things.

That TRSDOS 1.3 (and later LDOS) actually could do full interrupt-driven
I/O, INCLUDING high-speed modem drivers.

That TRSDOS 1.3 and later could be made to work REMOTE, including full
terminal mapping (!). Yes, I really >did< implement this.

That TRSDOS 1.3 had a number of "hooks" that could be exploited to work with
extended command interpreters, permission schemes, and all kinds of other
neat things.

That TRSDOS 6 was actually made into one of the first multitasking "PC"
operating systems by yours truly. Yep, you got it..... and that the "TSR"
modular load-and-stay-resident feature that all PC'ers hate and love today
was also used widely on TRSDOS 6 -- for things like remote terminal control,
remote terminal character mapping (use your VT100 or Televideo as a
CONSOLE!), interrupt-driven I/O good enough for 9600 baud dumps to FLOPPY
without losing characters, and much more... all things that Tandy said were
impossible to accomplish.

We still have a damn good BBS and remote access system available for the
TRS-80 Model IV's. It used to be sold, now it's in the archives for the
asking (uucp anon-download). Did nearly everything, and was way ahead of
it's time when it was in vogue....

--
Karl Denninger (ka...@ddsw1.MCS.COM, <well-connected>!ddsw1!karl)
Public Access Data Line: [+1 708 808-7300], Voice: [+1 708 808-7200]
Macro Computer Solutions, Inc. "Quality Solutions at a Fair Price"

Karl Denninger

unread,
May 15, 1990, 3:41:54 PM5/15/90
to
In article <58...@lll-winken.LLNL.GOV> stic...@brahms.llnl.gov (Jim Stichnoth) writes:
>
>TRSDOS had a slightly better copy protection scheme for floppies. On a
>Model III, the backup routine would copy the entire disk, and then go back
>and copy track 17 (the directory track). While copying the directory track,
>it would determine which files were protected and remove their directory
>entries.

Actually, once you figured out how it worked, you could defeat it easily.
The protection copy flag (number of legal copies) was one byte in the boot
sector. One quick patch, and zap -- no more protection.

Once you knew how to do that, you then did the same thing to the directory
entries (one bit this time on each) to tell the system that the files
weren't "protected". The end result was that you could then use the copy
command......

This worked quite well for Zork and many others.

David H. Thornley

unread,
May 16, 1990, 1:42:54 PM5/16/90
to
In article <1990May15.1...@ddsw1.MCS.COM> ka...@mcs.MCS.COM (Karl Denninger) writes:
>In article <TJFS.90Ma...@tadtec.uucp> tj...@tadtec.uucp (Tim Steele) writes:
>>I never came across that backup wrinkle... very nice. Instead, I
>>disassembled the whole of TRSDOS... very interesting. That DOS was
>>years ahead of its time, really...
>>
>
>Yep. There are a number of things that few know about the infamous TRS-80,
>especially the Models III and IV.
>
>Like that TRSDOS 1.3 (the first "working" TRSDOS) could be coaxed into
>destroying files -- by doing some rather normal things.

The first "working" TRSDOS was actually 2.0/2.1/2.2/2.3 for the Model I.
I don't remember if they ever got rid of the "feature" that deleting a file
without explicitly closing it first trashed the disk. (Naturally, I kept
saying "Now who would do something like that?" until I did it myself once
and realized just after I hit "ENTER" that I had trashed the disk! :-)

Also, the first good machine-language debugger I ever saw was DEBUG on
TRSDOS. Frankly, I've never seen anything better before or since. (I never
actually bought a debugger, so I'm comparing what came free with a TRS-80
with what comes free with "real" machines with MS-DOS or MACSBUG for the
Mac. It is possible that commercial debuggers are as good as that old DEBUG,
especially since some of the commercial stuff for the TRS-80 were reported
to be even better than DEBUG.)

I thought (and think) that the move from TRSDOS to MS-DOS was a real step
backwards.

David Thornley

Hank Shiffman

unread,
May 17, 1990, 2:40:32 PM5/17/90
to
In article <78...@latcs1.oz.au> step...@latcs1.oz.au (Philip J Stephens) writes:
>In article <58...@lll-winken.LLNL.GOV>, stic...@brahms.llnl.gov (Jim Stichnoth) writes:
>>
>> (Oh, and speaking of Zork, does anyone know how to solidify the rainbow in
>> Zork I? I was told there is a pot of gold there. That is the one thing I
>> was never able to solve.)
>
>*** SPOILER WARNING ***
>
> I'm not surprised you couldn't solve it; it doesn't seem to have any clues
>related to it!
>
> All you have to do is take the sceptre found in the coffin, walk up to the
>view of the rainbow, and raise the sceptre into the air!
>

Here's the way I rationalized this: rainbows are associated with
leprechauns and pots of gold. A leprechaun carries a wooden walking
stick known as a shillelagh. By that time I had solved most
everything else in the game and hadn't yet found a use for the stick.
So I guessed the leprechaun relationship and tried it. Voila!

Doug Jenner

unread,
May 17, 1990, 4:36:01 PM5/17/90
to
In article <135...@sun.Eng.Sun.COM> shif...@basselope.Eng.Sun.COM (Hank Shiffman) writes:
>In article <78...@latcs1.oz.au> step...@latcs1.oz.au (Philip J Stephens) writes:
>>In article <58...@lll-winken.LLNL.GOV>, stic...@brahms.llnl.gov (Jim Stichnoth) writes:
>>>
>>> (Oh, and speaking of Zork, does anyone know how to solidify the rainbow in
>>> Zork I? I was told there is a pot of gold there. That is the one thing I
>>> was never able to solve.)
>>
>
>Here's the way I rationalized this: rainbows are associated with
>leprechauns and pots of gold. A leprechaun carries a wooden walking
>stick known as a shillelagh. By that time I had solved most
>everything else in the game and hadn't yet found a use for the stick.
>So I guessed the leprechaun relationship and tried it. Voila!
>

In some incarnations of Zork, the magic wand is a simple sharpened stick. In
others, it is a sceptre. The sceptre is rainbow coloured (a dead giveaway),
but any vertern of ADVENT knows that the rod creates the bridge. Not that
difficult of a puzzle if you have been around a bit.

D.
--
_Doug Jenner_ Model: Homo Sapiens, version 0.24, Alpha release
dje...@sun.com
The above views are soley those of the author, and not necessarily those of
Sun Microsystems, Inc. 'Though I haven't really asked them about it.

Eric Postpischil (Always mount a scratch monkey.)

unread,
May 18, 1990, 7:27:54 AM5/18/90
to

> All you have to do is take the sceptre found in the coffin, walk up to the
> view of the rainbow, and raise the sceptre into the air!

That's a new one on me. In the version I had, waving the stick worked.
That's the pointed stick which I think was found near the boat and which
would puncture the boat if you weren't careful.


-- edp

r.peterson

unread,
May 19, 1990, 5:15:16 AM5/19/90