Rare rom I believe is an Electronic Arrays custom programmed for Tektronix, only carrying basic markings. This has a rougher white ceramic top, but a full gold base and legs. I can't be positive but this package style seems to be from 1972.

I believe this might be a character rom for CRT graphic displays perhaps? Or some kind of microcode for early CPU use like with the 4004 perhaps? It carries a Tektronix part number which crosses to an EA (electronics arrays) 40194 ROM.

Markings :

156-0293

underside:

D40121

I have no way to test this, it is intended as a display piece for your vintage IC collection!

LOC:25111

See the photos for details of the actual item you are buying! 

Yes I combine items to save on shipping cost. Yes I ship international, any difference in shipping price quoted from actual will be refunded - i cannot get accurate shipping quotes for heavy bulky items!

Any other questions let me know.