Nippon Calculating Machine Co., Ltd. (Busicom) Model 120-DN Exec Desktop Calculator
The Nippon Calculating Machine Co., Ltd. (NCM) Busicom Exec, Model 120-DN
is a desktop
AC-powered electronic calculator using a single MOS/LSI
(Large Scale Integration) IC manufactured by US chip maker
Mostek under contract to Nippon Calculating Machine Co., Ltd.(NCM)
The Mostek MK 6010 Calculator-on-a-Chip (Note NCM Logo on Chip Lid)
The MK 6010 Large Scale IC used in the Busicom Exec 120-DN was the first
commercial "Calculator on a Chip". The device was laid out and fabricated by
Mostek from a logic design created by NCM.
The Exec 120-DN is a follow-on to the earlier
Busicom Junior 120-DM
which marked the first use of the MK 6010 calculator chip. The 120-DN
is functionally equivalent to the earlier machine,
with updates mainly in styling, and a slightly smaller form-factor.