Write Only Memory
An engineer at Signetics, frustrated by the long and useless sequence of approvals for data sheets (during which no actual checking occurred), once made up a spec for a "Write Only Memory" (a "WOM") and sent it along with a batch of other data sheets to be approved. After all, if you are selling "Read Only Memories", why not have a "Write Only Memory"? It’s perfectly logical – – which is why the managers saw nothing wrong with the data sheet.
The WOM data sheet went through the approval chain, just fine, and wound up in Signetics’ new products catalog. This came to the attention of the managers at Signetics, only after customers began asking for price and delivery. Signetics shortly printed up new "corrected" databooks, without any WOMs, and asked for the "erroneous" ones to be returned. But customers soon got word of why they asked for returns, and hid them properly.
About 1974, Signetics bought a two-page, full-color spread in the April issue of ELECTRONICS Magazine, and published the WOM data sheet, as a (rather expensive) April Fool’s Joke. This version of the WOM data sheet shows the various features of Signetics’ Model 25120 "fully-encoded, 9046 x N Random Access, Write Only Memory". This advertisement has been saved, and greatly prized by engineers, for many years. We recently found a copy of this data sheet, in very good shape except for where it had been punched for a 3-ring binder. See the next pages.