The Real Story of the Write-Only-Memory (WOM)

I worked at Signetics as an engineer from about 1967 to 1979. One of my tasks in the Signetics MOS marketing group was to create data sheets for new products.

I wrote the 25120 WOM data sheet, copyrighted in 1972, as a lark to see what a Signetics WOM specification might look like. I used a humorous EIMAC specification as a basis. If you look on the last footnote on the 25120 data sheet, I had included, “Due credit to EIMAC for inspiration.”.

I had always admired an EIMAC high powered vacuum tube spoof data sheet put out by Eitel-McCullough,Inc. I saw it when I was a teen Ham Operator and must have memorized it. That was in the late 1940’s. You need the data sheet to see the relevance. It was labeled the Umac 606 and featured a photo of a vacuum tube which sports a plumber’s helper as an anode/plate. The specifications were precious and I adopted them rather freely for the 25120. A sister spoof product, the Wemac 1Z2Z featured a melted down power tube and similar specifications.

I used every semiconductor business inside-witticism I knew plus whatever the MOS Department employees could add. And I used most every funny idea I could lift from the EIMAC data sheet. There isn’t a word on the data sheet that doesn’t have a hidden meaning. I included Department Head Jim Kane’s and Production Head Tom Arrieta’s names in the notes to help make them famous (also IC gurus Yagura, Kashkooli and Converse). My booth mate was Bill Sanderson, he helped with ideas and as a critic. Probably there are a lot of Engineer Jerry Lawson’s contributions too as he was a real comedian with lots of semiconductor experience. He could have invented the WOM concept. He did invent the “SCROM”. I doubt if any one else knows what that is. I’ll add later. (Jerry passed in April, 2011.)

Although the original idea of a WOM is sometimes credited to the appearance of the 1972 data sheet, I don’t know if the term “Write-Only-Memory” or  WOM necessarily originated with us, but we gave it a number and a life. We passed the Write-Only-Memory data sheet around the office and to our salesmen and found it had possibilities. At a minimum it was an ice breaker. The spoof data sheet was included in the Signetics data book intentionally.

Our PR guy, Roy Twitty, caught the fever and prepared a hilarious press release to hit April 1, 1973. That spoof conferred the title of Dr. on me, everything else is surely accurate. The only copy I have looks like a draft because of a number of typos that proof reading would have caught.

 

21 thoughts on “The Real Story of the Write-Only-Memory (WOM)

  1. Stiletto

    It just so happened that I was looking into the Signetics 25120 and other similar jokes this evening like the National Semiconductor LM0901A1411090451C and others, after having discovered them for the first time only several years ago, when I stumbled upon your website. Love the story so far. I’m going to link it a few places and hopefully it will get the attention it deserves. Email me and I’ll be happy to tell you a little more about what I’ve been looking into.

    Reply
    1. jgcurtis Post author

      Thanks Jim. I will treasure it but it’s not the one that inspired me. It had a melted power tube It will turn up.

      Reply
    1. jgcurtis Post author

      Those are counterfeit and poor ones at that. Compare with the real McCoy in my blog. Sure, good quality. They are original artwork! But not the real original. Thanks anyway (-:

      Reply
  2. William D. Richards

    I remember when I heard about this in high school in the late seventies, just before the personal computer revolution really caught on. The moment I heard the name (Write-Only Memory) I burst out laughing, as I understood the nature of just such a technology.

    The joke stuck with me. Twenty years later, I submitted an idea for a product that used the concept of WOM: one would plug it into a computer, download the relative files into it, and it would display the contents of those files on its screen, but the files themselves could not be unloaded from the device. When the user was finished with the data file, the user could just delete it from the device. The use of the WOM concept was to keep the data files from being pirated.

    The product never made it to even to prototype stage. The big wigs said it would never catch on, because, “Nobody would want to read a book on a digital screen.”

    Reply
  3. Mike

    Found it.
    Reprinted in http://ns81.webmasters.com/*w3hzu.org/addon/w3hzu.com/pdfdocs/newsletters/2007_04.PDF

    WEMAC- THE ONE ZED TWO ZED TUBE
    Slightly tentative data (see notes at bottom)
    The Weman 1Z2Z is a Traveling Ripple tube (1) designed for
    the phone man (2) superceding the UMAC 606.
    The 1Z2Z is of radical (3) design. It does however still retain the
    urinated tungsten (4) cathode which proved so successful in the UMAC 606
    (5). Cooling is accomplished by ventilation and removing the heat. This is
    readily done at the North Pole (6) by means of a fan. At the Equator, a
    bigger (7) is needed.
    The Y3 Grid used in earlier tubes has been superceded by a Y4
    grid in the 1Z2Z. Since the tube does not have a grid, the choice is a wise
    one (8).
    The profulgment stigmetic type of construction permits an
    untrimmed electron beam to pass into the hypodirec channel (9) where the
    beam is modulated by calistral encabulization, thus producing the ripple.
    This ripple is amplified in the Galoidal Plammet (10) cavity and is carried
    by mongratic diffusion into the catcher cavity. One can readily see that
    applications are unlimited (11).
    General Characteristics
    Electrical:
    Filament: Urinated Tungsten
    Voltage – adjust (12)
    Current – adjust (12)
    Amplification factor (Average) 30 Ohms
    Indirect capacity – Ghommet Mongrat (13) – 1/5th gallon
    Mechanical:
    Maximum overall dimensions – 36 X 22 X 34 inches
    Height – 5 feet 6 inches
    Shipping weight (14) – 123 lbs
    Application of the 1Z2Z
    Because of its unique construction, the 1Z2Z can serve as as
    oscillator, modulator, or amplifier. The 1Z2Z also acts as a memory tube. It
    has a remarkable memory for certain telephone numbers and next years
    income taxes. When used as a Flip-Flop circuit, the bias must be adjusted to
    prevent flipping out a telephone number while flopping out a tax return..
    Many of the applications are secret and highly classified (15).
    Notes:
    (1) A traveling ripple has a much higher frequency then a traveling wave
    (2) A noted phone man, W6QD, states as follows: “While we’re not so
    young as we used to be, we are indeed honored to be able to make a
    pregnant statement regarding the 1Z2Z tube. We believe that the 1Z2Z
    tube will ultimately replace the transistor.
    (3) Excuse us, Mr. McCarthy
    (4) In order to obtain a pure source of Uranium for treating the Tungsten,
    a plant for processing this material was established in the Virgin
    Islands. Subsequent developments however, showed that the raw
    material from this source is not different from that of any other source.
    (5) A data sheet on the 606 will be furnished upon request.
    (6) Eskimos do not fish in Winter.
    (7) Wonder what became of Sally?
    (8) Y4
    (9) It will also work on Channel 13.
    (10) Sounds like “Sputnik”
    (11) i.e. Burning off warts
    (12) Tentative date
    (13) users of the 1Z2Z are cautioned that the price is subject to change
    without notice. The raw materials used in the Mongrat & Golmmet are
    imported from Hong Kong, and the cost of these materials vary
    depending upon the prevailing rate of exchange of the Hong Kong
    Tael. Few people realize that the Tael is the ancient media of
    monetary exchange of China. The Tael as a medium of exchange
    actually exists in the form of a slipper like shaped piece of soft silver.
    In fact, the silver is so pure and soft that it may be readily cut into
    sections with a sharp knife. This method is used in making change,
    and the sections are simply known as “pieces of silver”.
    (14) With dimensions like that, anyone would be crazy to ship it
    (15) Watch Winchell’s column

    Reply
  4. Mike

    Found it. April, 2007, The VHF Transmitter -Keystone VHF Club, Inc.
    http://ns81.webmasters.com/*w3… [webmasters.com]
    Looks like it was originally printed in 1953 sometime.

    A CLASSIC FROM THE PAST
    (Printed in the November 1, 1957 issue of the
    Transmitter Newsletter)
    WEMAC- THE ONE ZED TWO ZED TUBE
    Slightly tentative data (see notes at bottom)
    The Weman 1Z2Z is a Traveling Ripple tube (1) designed for the phone man (2) superceding the UMAC 606. The 1Z2Z is of radical (3) design. It does however still retain the urinated tungsten (4) cathode which proved so successful in the UMAC 606 (5). Cooling is accomplished by ventilation and removing the heat. This is readily done at the North Pole (6) by means of a fan. At the Equator, a bigger (7) is needed.
    The Y3 Grid used in earlier tubes has been superceded by a Y4 grid in the 1Z2Z. Since the tube does not have a grid, the choice is a wise one (8). The profulgment stigmetic type of construction permits an
    untrimmed electron beam to pass into the hypodirec channel (9) where the beam is modulated by calistral encabulization, thus producing the ripple. This ripple is amplified in the Galoidal Plammet (10) cavity and is carried by mongratic diffusion into the catcher cavity. One can readily see that
    applications are unlimited (11).

    General Characteristics
    Electrical:
    Filament: Urinated Tungsten
    Voltage – adjust (12)
    Current – adjust (12)
    Amplification factor (Average) 30 Ohms
    Indirect capacity – Ghommet Mongrat (13) – 1/5th gallon
    Mechanical:
    Maximum overall dimensions – 36 X 22 X 34 inches
    Height – 5 feet 6 inches
    Shipping weight (14) – 123 lbs
    Application of the 1Z2Z
    Because of its unique construction, the 1Z2Z can serve as as oscillator, modulator, or amplifier. The 1Z2Z also acts as a memory tube. It has a remarkable memory for certain telephone numbers and next years income taxes. When used as a Flip-Flop circuit, the bias must be adjusted to prevent flipping out a telephone number while flopping out a tax return.. Many of the applications are secret and highly classified (15).
    Notes:
    (1) A traveling ripple has a much higher frequency then a traveling wave
    (2) A noted phone man, W6QD, states as follows: “While we’re not so
    young as we used to be, we are indeed honored to be able to make a
    pregnant statement regarding the 1Z2Z tube. We believe that the 1Z2Z
    tube will ultimately replace the transistor.
    (3) Excuse us, Mr. McCarthy
    (4) In order to obtain a pure source of Uranium for treating the Tungsten,
    a plant for processing this material was established in the Virgin
    Islands. Subsequent developments however, showed that the raw
    material from this source is not different from that of any other source.
    (5) A data sheet on the 606 will be furnished upon request.
    (6) Eskimos do not fish in Winter.
    (7) Wonder what became of Sally?
    (8) Y4
    (9) It will also work on Channel 13.
    (10) Sounds like “Sputnik”
    (11) i.e. Burning off warts
    (12) Tentative date
    (13) users of the 1Z2Z are cautioned that the price is subject to change without notice. The raw materials used in the Mongrat & Golmmet are imported from Hong Kong, and the cost of these materials vary depending upon the prevailing rate of exchange of the Hong Kong Tael. Few people realize that the Tael is the ancient media of monetary exchange of China. The Tael as a medium of exchange actually exists in the form of a slipper like shaped piece of soft silver. In fact, the silver is so pure and soft that it may be readily cut into sections with a sharp knife. This method is used in making change,
    and the sections are simply known as “pieces of silver”.
    (14) With dimensions like that, anyone would be crazy to ship it
    (15) Watch Winchell’s column

    Reply
  5. David Warman

    The bit that has stuck with me (visually) is the symbol for the Drain.

    Into Reality: I have a drawer full of about 4 different formats of tape backups. I consider each and every one to be Write Only Memory – I have never been able to actually retrieve anything I saved there.

    Reply

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