The datasheet PDF doesn't contain an obvious date, but it's is clearly scanned and it also contains a sample circuit for connecting it to an IBM PC via the ISA

The datasheet PDF doesn't contain an obvious date, but it's is clearly scanned and it also contains a sample circuit for connecting it to an IBM PC via the ISA bus. So somewhere between 1981 and 1995, perhaps. There's a document id on the last page that may indicate it's from 89. https://www.analog.com/media/en/technical-documentation/data-sheets/AD1139.pdf https://www.analog.com/media/en/technical-documentation/data...