The prototype includes five different white ceramic 16 pin DIP package ICs. A post-it attached has the prototype number listed under each item. These numbers read "1->4100, 2->4110, 3->4115, 4->?". There is a business card with the ICs that reads "First ISOPLANAR 256 BiT RAM - 6/22/71" and on the other side "(415)962-2136/7, JOHN P. GATES, director of MOS and memory, 464 Ellis Street, Mountain View, California 94040" to which a chip is adhered.