Unknown EPROM

[Cauf]

Hello  I found this unknown ( for me)  EPROM in my 1992 car's ECU. Anybody has some info on this one ?  Grts Patrick

[BrokenYugo]

Custom numbers are common in ECUs, I'd guess pin count and PCB layout should give enough clues to dump it as a 27Cxxx.

[Cauf]

Custom numbers are common in ECUs, I'd guess pin count and PCB layout should give enough clues to dump it as a 27Cxxx.

You could be correct.  Here is my info on this ECU.

The MSA-11 ECU is used in older cars like a BMW e36 325TDS which also will be the example. It
has two 27C256 EPROM's inside (UV-erasable). The EPROM's are mounted in sockets, so no
soldering is needed. On the EPROM with the lowest software number are the limitation maps,
drivers wish and the quantity adjuster map. The EPROM with the higher software number
contains the Beginning of injection maps (3 the same maps in this case). Sometimes other
EPROM's are used like the 87C257 (UV-erasable). The MSA-11 is used in the following cars:

[m k]

Since you know their internals you also know how to read them.

First row has -20, that's an access time of 200ns.
So practically any current pin compatible will do.
I'd use 28C series E2PROM.