And it verifies 1K x 8-bit by people who used the chip in 1989.
However, based on date markings visible on the chip, it dates from at least 1985. Reviewing Sony Semiconductor IC Data Book (Memories) 1989 and Sony Semiconductor IC Data Book (Memories) 1990 did not turn up a datasheet. It must either exist in earlier data books that are as yet unscanned, or it was never released.