M29W040B-55K1 - 4 Mbit (512Kb x8) non-volatile memory that can be read, erased and reprogrammed. These operations can be performed using a single low voltage (2.7 to 3.6V) supply. On power-up the memory defaults to its Read mode where it can be read in the same way as a ROM or EPROM. If you also need programming service: https://www.heinpragt.nl/?product=eeprom-programming https://elecena.pl/product/28683892/m29w040b-55k1-512k-x-8-flash-memory-plcc-32 2025-05-13 https://elecena.pl/product/28683892/m29w040b-55k1-512k-x-8-flash-memory-plcc-32 2025-05-17