Vintage 100ns RAM chips, 256k x 1, page mode, DIP package.  Made in the USA by Micron Technologies.

This part is a drop-in replacement for a variety of similar chips with different part numbers from various manufacturers.  It will work as a TI TMS4256-10NL (or slower), and any number of the 41256-10 (or slower) chips and their equivalents.

Listing is for 4 ICs per lot.