Steve Lewis wrote: The major (and primary reason for the 4004 and the MCS-4 family existing in the first place) was Nippon Calculating Machine Co and their Busicom 141-PF electronic printing desktop calculator. NCM went to the US looking for a chipmaker (the capability for the level of integration required to make such a chipset did not exist in production form anywhere else in the world at the time), and two companies were engaged to develop a chipset for NCM, one being Intel, and the other being Computer Design Corporation. As history clearly points out, Intel won the competition, developing a chipset based on the 4004 CPU, and some peripheral chips (RAM, ROM, I/O) that ended up being the operating element of the NCM/Busicom 141-PF Calculator. The 141-PF is a very famous calculator for this reason, but is otherwise (by appearance and function) a very ordinary calculator for the time. The fact that it had "Intel Inside" (though the term didn't exist at the time), using the world's first commercially available microprocessor chipset made with MOS Large Scale Integration technology, makes the 141-PF (and the OEM copies; the NCR 18-36 and the Unicom 141). Two versions of the machine were made, one that was a four-function machine, and another that added an extra ROM that added a square root function. Other devices were subsequently developed that used the 4004 as their computing core, such as digital scales, electronic cash registers, and various other electronic devices. This was only possible because initially, Nippon Calculating Machine Co. had exclusive rights to the use of the chipset. Due to some financial difficulties, NCM renegotiated the contract with Intel, removing the exclusivity clause in return for Intel forgiving some money owed on the development of the chips. This allowed Intel to sell the chipset to the open market. Once this occurred, Intel aggressively marketed the chipset as the MCS-4 microprocessor system, providing extensive documentation, development tools, both hardware and software, and lots of support for anyone wishing to develop an electronic system based on the 4004. The Busicom 141-PF calculator and its OEM versions were the first commercially-available electronic devices that had a general-purpose microprocessor with firmware implementing the machine’s logic, and thus represent the historical benchmark. These were actual products that were sold under the Busicom brand as well as NCR and Unicom. It isn’t known how many of these machines were actually made, but enough were made that they can still (rarely, though) be found today. Nippon Calculating Machine Co. in Japan manufactured and distributed them under their Busicom brand name, as well as providing the machines with subtly changed color schemes for cabinet/keyboard to OEM customers, which would market, sell, and service them under their own brand names. Rick -- The Old Calculator Museum https://oldcalculatormuseum.com P.S. If anyone out there has one of these calculators lying around gathering dust, working or not, and would like to have it see new life as part of a museum exhibit, please get in touch with me.