Write-only memory (WOM), the opposite of read-only memory (ROM), began as a humorous reference to a memory device that could be written to but not read, as there seemed to be no practical use for a memory circuit from which data could not be retrieved. However, it was eventually recognized that write-only memory also describes certain functionalities in microprocessor systems. [1] The concept is still often used as a joke or euphemism for a failed memory device.
The first use of the term is generally attributed to Signetics, whose write-only memory literature, created in 1972 as in-house practical joke, is frequently referenced within the electronics industry, [2] a staple of software engineering lexicons, [3] and included in "best hoaxes" collections.[ citation needed]
A "Write-Only Memory" datasheet was created "as a lark" [4] by Signetics engineer John G "Jack" Curtis, [5] inspired by a fictitious and humorous vacuum tube datasheet [6] from the 1940s. Considered "an icebreaker", it was deliberately included in the Signetics catalog. [5] Roy L Twitty, a Signetics PR representative, released a tongue-in-cheek press release touting WOM on April 1, 1973. [7]
Instead of the more conventional characteristic curves, the 25120 "fully encoded, 9046×N, Random Access, write-only-memory" data sheet included meaningless diagrams of "bit capacity vs. Temp.", "Iff vs. Vff", "Number of pins remaining vs. number of socket insertions", and " AQL vs. selling price". The fictional device required a 6.3 VAC Vff ( vacuum tube filament) supply, a +10 Vcc (double the Vcc of standard TTL logic of the day), and Vdd of 0±2% volt (i.e. ground). It was specified to run between 0 and −70°C. [8]
In 1982, Apple published their official Apple IIe Reference Manual (part number A2L2005), [9] which included two references to write-only memory:
On page 233:
On page 250:
Originally written by Bruce Tognazzini, the write-only memory definition was unfortunately set upon by certain editors lacking a sense of humor. The second sentence originally read, "Approximately one inch on each side, Farnsfarfle's original prototype has so far been used...." The editors insisted the original contained a misplaced modifier whereas Tognazzini was equally adamant that Farnsfarfle was a very small man. The editors won. [10] [11]
The 1995 Computer Contradictionary book discusses EWOM, or Erasable Write-Only Memory (an analogy of EPROM), a memory copyrighted by IBM (Irish Business Machines), which allows the data to be written to and then erased, for memory re-use. [12]
With the explosive growth of the amount of digital video data online and in private use, there emerged a common joke that video tapes and other analog video media were "write only memory", as very little of it was still viewed. [13] [14]
The 25120 WOM joined a family of equally useless, fictitious devices made before and since, including the dark bulb, dark-emitting diode, WAS gate, and Inoperational Amplifier; [15] and earlier, the Umac 606 Infernal Anode Phantasatron and the Electrovoice Rearaxial Softspeaker. [16] (The Phantastron is a real, if obsolete, circuit for generating precision sawtooth waves.)
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cite web}}
: CS1 maint: archived copy as title (
link)
Write-only memory (WOM), the opposite of read-only memory (ROM), began as a humorous reference to a memory device that could be written to but not read, as there seemed to be no practical use for a memory circuit from which data could not be retrieved. However, it was eventually recognized that write-only memory also describes certain functionalities in microprocessor systems. [1] The concept is still often used as a joke or euphemism for a failed memory device.
The first use of the term is generally attributed to Signetics, whose write-only memory literature, created in 1972 as in-house practical joke, is frequently referenced within the electronics industry, [2] a staple of software engineering lexicons, [3] and included in "best hoaxes" collections.[ citation needed]
A "Write-Only Memory" datasheet was created "as a lark" [4] by Signetics engineer John G "Jack" Curtis, [5] inspired by a fictitious and humorous vacuum tube datasheet [6] from the 1940s. Considered "an icebreaker", it was deliberately included in the Signetics catalog. [5] Roy L Twitty, a Signetics PR representative, released a tongue-in-cheek press release touting WOM on April 1, 1973. [7]
Instead of the more conventional characteristic curves, the 25120 "fully encoded, 9046×N, Random Access, write-only-memory" data sheet included meaningless diagrams of "bit capacity vs. Temp.", "Iff vs. Vff", "Number of pins remaining vs. number of socket insertions", and " AQL vs. selling price". The fictional device required a 6.3 VAC Vff ( vacuum tube filament) supply, a +10 Vcc (double the Vcc of standard TTL logic of the day), and Vdd of 0±2% volt (i.e. ground). It was specified to run between 0 and −70°C. [8]
In 1982, Apple published their official Apple IIe Reference Manual (part number A2L2005), [9] which included two references to write-only memory:
On page 233:
On page 250:
Originally written by Bruce Tognazzini, the write-only memory definition was unfortunately set upon by certain editors lacking a sense of humor. The second sentence originally read, "Approximately one inch on each side, Farnsfarfle's original prototype has so far been used...." The editors insisted the original contained a misplaced modifier whereas Tognazzini was equally adamant that Farnsfarfle was a very small man. The editors won. [10] [11]
The 1995 Computer Contradictionary book discusses EWOM, or Erasable Write-Only Memory (an analogy of EPROM), a memory copyrighted by IBM (Irish Business Machines), which allows the data to be written to and then erased, for memory re-use. [12]
With the explosive growth of the amount of digital video data online and in private use, there emerged a common joke that video tapes and other analog video media were "write only memory", as very little of it was still viewed. [13] [14]
The 25120 WOM joined a family of equally useless, fictitious devices made before and since, including the dark bulb, dark-emitting diode, WAS gate, and Inoperational Amplifier; [15] and earlier, the Umac 606 Infernal Anode Phantasatron and the Electrovoice Rearaxial Softspeaker. [16] (The Phantastron is a real, if obsolete, circuit for generating precision sawtooth waves.)
{{
cite web}}
: CS1 maint: archived copy as title (
link)