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April 1, 1972: Write Only Memory
Embedded Geek writes "While digging around Jack Ganssle's site, I came across an amusing prank from days gone by. In 1972 Signetics recognized April Fools day by printing a full color datasheet (scanned sheet 1 and sheet 2 here) for a Write-Only Memory (which accepts data but never reads it back), a considerable effort when documents were made via literal "cut and paste". Packed with jokes both obvious (a graph of "number of pins left versus number of insertions") and subtle ("Vdd = 0V +/- 2%") it's worth a chuckle."
Writing perl code! Write once, read never.
Websurfing done right! StumbleUpon
I thought I just had to avoid reading slashdot one day a year to avoid April Fools crap.
You people ARE nerds! Jebus. I thought everyone was just faking it!
I have been pwned because my
I get a lot of spam, so I've been working on a hardware accelleration card for /dev/null. This'll save me having to develop my own design in an expensive FPGA.
Something they can sell that has Perfect Copy Protection!
There are circuits in use that are essentially a write-only memory like this (but without the need for a 6 foot fan!), combined with a comparator and possibly a one-way encrypter. You can store an encrypted password in there, which then can never be read back in its encrypted form. Plaintext phrases can be encrypted and compared against the stored password.
One existing application is on debit cards (cards that are charged with a cash amount on the card itself).
If construction was anything like programming, an incorrectly fitted lock would bring down the entire building...
This has been in The Jargon Lexicon for ages. Don't all slashdotters know of it?
Ne mæg werig mod wyrde wiðstondan, ne se hreo hyge helpe gefremman.
You mean like the windows registry?
:)
Crap goes in, but doesn't seem to go out until you have to reinstall a month later
First posts are write only.
The Day Today - Game Warden to the Events Rhino
I wasn't born yet, i do remember :)
On the BBC Micro you could add 16Kbyte banks of 'sideways RAM'. I remember that some upgrades had a 'read protect' switch, which sounded very odd. I think it was for compatibility; read protect made the upgrade effectively invisible.
-- Ed Avis ed@membled.com
"The 25120 will provide 50% higher speed than you will obtain".
If construction was anything like programming, an incorrectly fitted lock would bring down the entire building...
I didn't know that DAT backup tapes were invented in 1972... ;-)
Brilliant: slip-on latex protectors for preventage of VD!! (Voltage Destruction) Pill packaged devices do not require protection!
My favorite feature of this device is that typical bit capacity is 35% to 75% of "guaranteed" bit capacity.
I'd rather thought that /dev/null was the most elegant WOM out there...
/dev/null? I personally think it's about time we found out how much you can stash in there.
Heck, they even coded it such that it has infinite capacity, or a very high capacity in any case.
Could someone dedicate a machine for a few years with a shell script running an infinite loop writing data to
Blearf. Blearf, I say.
After laughing it up for a bit, their boss walks in. He is visibly angry.
I design user interfaces for a free network management application,
The real question is, why would someone make a first post in the first place?
However, through the use of simple mathematics I've deducted a formula that explains this habit-
sP + aF / P = Need of being the first poster
You see, the persons small penis (sP) factor is added to his annoyance factor (aF) and divided by any real personality this poster may have (P), creates the probability of having a first post, as well as the need to be the first poster.
Therefore, the average first poster believes that by being the first poster, he will enlarge his penis size. Unfortunately, this is most opposite of what *really* occurs.
fP = P / sP - wFOP = First poster's penis size.
As you can see, the first post has the effect of actually *shrinking* his penis, as the personality factor is divided by his existing small penis, minus an additional amount based on the annoyance factor of the first post itself. So, in reality, these people are causing long-lasting damaging effects to their genitals.
And to answer your question, no, I DON'T have anything better to do than post nonsensical, offtopic garbage on a message board.
Robort knows all.
Because of the employment of the signetics' proprietary Sanderson-Rabbet Channel the 25120 will provide 50% higher speed than you will obtain.
Err .. mmmkay ??!?!?
"640k of Write-Only Memory ought to be enough for anybody".
Baz
I remember a datasheet from Phillips on the DED.(Dark Emitting Diode) and a Texas instruments publication on a spec for the FUDGE gate.
It isnt new, but that one is obviousally old enough to possibly be the first....
Do not look at laser with remaining good eye.
but you are wrong.... cash cards/chips CAN be read. you have to know how much is left on it. and a password storage as you say ALSO can be read as you have to have an indication if the match was positive.
so in fact if you get ANYTHING out of a device it does in fact have a read capability.
Do not look at laser with remaining good eye.
On a similar line, somewhere at home I have a spoof datasheet from Nominal Semidestructors giving information about the new Polish Operational Amplifier.
What I'm missing, however, is my copy of the table of variation of pi with temperature and pressure, which I believe was given to all engineering freshmen at Cambridge at one time. If anyone can help me to locate a new copy I'd be grateful. Please reply here or email me (see homepage).
Every bloody emperor has his hand up history's skirt [Peter Hammill/VdGG]
They even planned far ahead. In 1972, "VFF = 6.3VAC" was obvious in itself, but for you youngsters that don't know about vacuum tubes they added the footnote "6. For the filament heater, of course."
Yes, it's now a very old joke, but it's been fun watching a new "generation" rediscover it every five years or so.
Did you see the "SEX[7]" note at the bottom of page 1? it says "[7] You have a dirty mind..."
If I recall correctly, both Signetics and National Semiconductor managed to sneak a few bogus datasheets into their released databooks from time to time. I first saw of this particular one a couple three years ago; I think someone posted a link to it on sci.electronics.design or a similar newsgroup.
If this technology could be incorporated into a CD or DVD, all of their "piracy" concerns go away.
Sure, there are some pesky customer satisfaction issues, but let's keep our priorities straight. OK?
I had used this very chip as an example of the problems of searching with Google in a prevous /. post - I was trying to find electronic forms of the datasheet, and was using it as an example of why I felt Google needed boolean searches.
/., I can find that thread with neither /.'s built-in search nor with Google.
/. ;>) follow - go read QST, for example. Why, I even heard Microsoft is getting into the act - they released a fake news release about focusing on security and reviewing their code, but I think they jumped the gun by a couple of months....
The really funny thing is, that while this created a bit of a message thread on
Making fake releases is a tradition many organizations (and
www.eFax.com are spammers
Yeah, my hand-writing is write-only, or so everyone tells me...
// file: mice.h
#include "frickin_lasers.h"
If you got hold of a card (and had the resources) you could still read and brute force the hash of course, or force a valid response at the appropriate point. However, that leaves the physical problem of reassembly of an IC with onboard EEPROM, and even if the card can still be made to fit into the readers it's probably going to be unreadable. All of which needs to be done before the card is cancelled. Quite an elegant solution for those "ultra-paranoid locations" really. ;)
UNIX? They're not even circumcised! Savages!
I protest, this chip is obviously not JEDEC compliant and is therefore prone to silent failure. RMS and EFF ought to kick their asses.
A caveman dreams of being us, the incalculable power and riches. We dream of being Q, then what?
... dev/null, in hardware ?
Oh, I can't help quoting you because everything that you said rings true
OTOH, I've never encounterd a write-only memory before. The Amiga had a write-once memory (kind-of silly really) but that's not the same.
BTW: Great post C.T., it sure brought back a lot of memories digging through hardware specs. from my embedded days! : )
Friends who work at Philips (which bought Signetics years ago) tell me that the 25120 datasheet may be updated and reissued. Keep an eye out for it once Philips gets a usable website.
Lacking <sarcasm> tags,
The data sheet for the 1Z2Z vacuum tube (circa 1966) contained items like a "urinated tungsten filament" and a monode structure (one less than diode), IIRC.
If humor exists prior to the Google...can anyone laugh?
Man discovers fire.
I know people who have copies of that data sheet.
Another one that was good for a laugh was the ``Damn Fast Op-Amp'' that appeared in a normal device catalog from one of the major electronics device manufacturers (like Signetics, Fairchild, National, or maybe even AMD -- I'm leaning toward the latter but I can't remember any more. Darned cobwebs.) I used to enjoy asking interns to look up some information for me in the catalog and wait to see if they noticed it. You could tell if they did from the laughter.
Another one from the same time frame (1980-ish) was the announcement -- on official IBM product sheets -- of a Galactic Edition' of the VM/CP (or was it VM/CMS?) operating system. This included advanced features like the one that allowed users to create and destroy their own planetary systems and such.
Oh those were the days. Bet you don't see stuff like this appearing in official company literature any more. Hell, there'd probably be someone suing the company after they'd been traumatized upon seeing such offensive material (like `damn') or claiming fraud when their personal solar system didn't appear.
CUR ALLOC 20195.....5804M
Back in the days before memory came on SIMMs, a few shady PC hardware manufacturers included "write-only memory" on their motherboards. These devices made the system look like there was an impressive amount of memory on the motherboard, but in actuality they were just molded plastic with unconnected IC pins, filling the spots one would put real RAM chips.
On board battery? Think of a SecureID card on steroids and you'll get the general idea.
UNIX? They're not even circumcised! Savages!
Back when WORM drives were all the rage, some engineers at Atari actually implemented a worn: (Write Once, Read Never) device in Atari BASIC. I don't remember how it was done (it's buried in an old issue of Compute! that I probably threw out years ago) but I actually got to try it out on a computer at the school I was going to (back in the day when everyone had Apple ][s, this school was using Atari 800s).
/dev/null.
It was just an Easter Egg; I suppose some Unix geek at Atari just decided it needed its own equivalent of
/Brian
There was an amusing press release that accompanied the Signetics WOM.
Umm wouldn't 668 be the next door to the beast seeing as 667 would across the street?
Take his advice seriously people. He would know about this.
I thought write-only memory was Microsoft's solution to the problem of memory protection in Windows.
You know, misbehaving applications accidentally used to scribble on other apps' memory spaces. When Microsoft forced the PC industry to install banks of WOM, suddenly every crash became an application error--those applications were not conforming to the Windows API. Instead of scribbling on another application's memory, the app should have been scribbling to the WOM.
It was brilliant because overnight Microsoft foisted millions of dollars in OS support expenses on to application vendors.
He looked at me and said, "Kid, we don't like your kind, and we're gonna send your fingerprints off to Washington."
DAT is MORM (mangle-on-read memory). or maybe TORM (tangle-on-read memory).
--
"It is now safe to switch off your computer."
...partcularly in hardware encryption (Debit cards, PVRs, Access control systems, whatever. The point is that a chip has basicly two functions: SetKey(key) and Decode/Encode(data). You set the key, but you can never read the key. Of course the chip will use the key internally to come from plaintext to chipertext or vice versa, but as long as the encryption is strong it doesn't matter. (Def. of strong: Having plain & ciphertext doesn't help to find the key, most algorithms today are strong, the zip encryption is weak though).
Of course this means you need a specialized chip, and not a general CPU, which is overkill in many cases..
Kjella
Live today, because you never know what tomorrow brings
Not truly write-only memory (in the sense that you could get a value, albeit a painfully useless one), but it seems to come close to the spirit.
This was a pants-wetter back in 1972. Though I remember some different tearsheets -- they had marketing material as well, I think. One showed a "modified TO-5 case" that was in fact a photo of a water tower. The WOM campaign became a bit of cult humor for a generation of engineers and hobbyists.
-- We all have enough strength to endure the misfortunes of other people. La Rochefoucauld
I enjoyed it muchly back in the '80s when I first saw it, and now I will have a computer version...much better than the photcopied version that was many generations old...
ttyl
Farrell
CAN-CON 2019 - Ottawa's only book oriented Science Fiction Convention! October 18-20, Sheraton Hotel, Ottawa, Canada h
My old man was an eletrical engineer at Control Data for many years. He brought home doezens of things like this. I remember specifcations for the Write-Only Memory. I remember the FED (Flame-Emitting Diode; a cover photo from EDN magazine), the NED (Noise-Emitting Diode), alternative logic gates like the "DON'T" gate (no matter what two bits are input, the output is zero). I remeber even linear components like the IN-OP AMP. I loved this stuff. My dad was also a radio amateur and he and friend wrote an article proposing solving the spectrum shortage by using the negative freqeuncy spectrum. They included diagrams showing you how to bury your antenna and stick the ground rod up in the air.
Who says engineers aren't funny (at least to each other)?
$5 / month hosted VPS on linux = awesome!
Way back in the day (1981), one of my friends had a EE textbook with a "black box" circuit. No big deal, except that Snoopy(tm) was lying down on the black box as if it were his doghouse.
Fascism starts when the efficiency of the government becomes more important than the rights of the people.
Be careful applying this formula. For many first posters, you will get a "divide by zero" error.
Are you saying many first posters are women?
Jake
Dating: while( 1 ){ call_girl(); get_rejected(); drink_40(); } return 0;
FYI, This data sheet made it into the Signetics IC handbook, which is where I first saw it back in my PDP 11/35 days. I liked the Drain pin. It was properly placed over the Bit Bucket to prevent spilling data.
The truth shall set you free!
A couple of weeks ago, I destroyed the swap partition on my linux box without any prior preparations, just to see what would happen. The machine had been up and running for weeeks. . .
Sadly, nothing happened. I guess that's what I get for putting 1/2 gig of RAM in a machine that's primarily used for surfing the web . . .
"read protect made the upgrade effectively invisible."
I know I love buying new hardware, sticking it in my machine, and never hearing from it again.
--
Internet Explorer (n): Another bug -- that is, a feature that can't be turned off -- in Windows.