Instead of the more conventional characteristic curves, the 25120 fully encoded, 9046. Signetics write only memory 25120 datasheet bald engineer. The write only memory was a fake part signetics introduced april fools day many decades ago. A subreddit dedicated to news, articles and general discussions related to electronic systems and circuits. Out of frustration with the long and seemingly useless chain of approvals required of component specifications, during which no actual checking seemed to occur, an engineer at signetics once created a specification for a writeonly memory and included it with a. Writeonly memory has been one of the best practical jokes on the. A linux kernel module, that implements a driver for signetics 25120 write only memory wom. De1soc computer system with nios ii for quartus ii 15. The spoof data sheet was included in the signetics data book intentionally. We passed the writeonly memory data sheet around the office and to our salesmen and found it had possibilities.
Fools joke by signetics of the signetics 25120 writeonly memory chip. Signetics shortly printed up new corrected databooks, without any woms, and. My better firmware faster seminar will teach your team how to operate at a worldclass level, producing code with far fewer bugs in less. Our pr guy, roy twitty, caught the fever and prepared a hilarious press release to hit april 1, 1973. This being april 1, 2017, it seems to be an appropriate day to post the signetics 25120 fully encoded, 9046 x n, random access writeonly memory datasheet that per wikipedia. According to this wikipedia article, it was created by john jack curtis. The joker behind the signetics 25120 writeonly memory. I wrote the 25120 wom data sheet, ed in 1972, as a lark to see what a signetics wom specification might look like. By some definitions, a wom is a memory device which can be written but never read. The signetics 25000 series 9c46xn random access write. The real story of the writeonlymemory wom i worked at signetics as an engineer from about 1967 to 1979. Interestingly the address in the datasheet, i think, was the original site. Signetics 25120 fully encoded, 9046 x n, random access.
Remove read only write protection on micro sd 2gb memory card. In 1975 they were bought by philips semiconductors, which is now nxp. Signetics 25120 9046xn random access writeonlymemory. Now and in years past, electronic engineers and hobbyists alike have enjoyed the classic 1972 april fools joke by signetics of the signetics 25120 writeonly memory chip. Now it seems that the previously anonymous practical joker has identified himself and stepped forward with new information to correct and complete the story. Initially there seemed to be no practical use for a memory circuit from which data could not be retrieved. One of my tasks in the signetics mos marketing group was to create data sheets for new products.
Writeonly memory article about writeonly memory by the. Signetics 25120 fully encoded, 9046 x n, random access writeonly memory cool product report. Signetics writeonlymemory datasheet pdf link reddit. Writeonly memory wom is the opposite of readonly memory rom. De1soc computer system with nios ii 1introduction 2de1.89 152 434 634 271 133 1167 320 1359 378 618 974 286 465 802 933 1360 583 1235 569 221 1020 531 107 717 1411 206 386 926 820 123 1111 23 1454 592 594 1111 1399 1132 59 218