SEEQ DQ52B33 differences to 28C64

Seems like there are a few old timers on this message board, which is good. Anyone know why a 28C64 doesn't work (in write mode) when used as a replacement for the SEEQ 52B33?

I can get the host (old computer system) to read the 28C64 (once I program it externally) but it fails to write to it for some reason. Did the SEEQ part have something unusual regarding its write mode??

I've tried a few different brands of 28C64 (Atmel, Microchip) they all seem to fail after writing to the first byte.

I Found it wow

Gosh thanks John, amazing, the real thing, I've been looking for years!

OK Here are Datasheets for 28C64

Now here is some Goodies for 28C64