Editing Zilog Z80 (section)

=== Exxon investment, detailed development begins ===
While still being set up, the industry newsletter ''Electronic News'' heard of them and published a story on the newly formed company. This attracted the attention of Exxon Enterprises, [[Exxon]]'s high-tech investment arm. At the time, in the midst of the recession, there was little [[venture capital]] available, with a total of $10 million for the entire industry being spent in all of 1975 (equivalent to ${{Inflation|US|10|1975}}&nbsp;million in {{Inflation/year|US}}). Someone from Exxon contacted the still-unnamed company,{{sfn|Faggin|Shima|Ungermann|2007|p=3}} and arranged a meeting that eventually led to them providing an initial $500,000 funding in June 1975 (equivalent to ${{Inflation|US|0.5|1975|r=1}}&nbsp;million in {{Inflation/year|US}}).{{sfn|Faggin|Shima|Ungermann|2007|p=8}}

With funding being discussed and a design to be built, Shima joined in February 1975.{{sfn|Faggin|Shima|Ungermann|2007|p=4}} Shima immediately set about producing a high-level design, adding several concepts of his own. In particular, he used his experience on [[NEC]] [[minicomputer]]s to add the concept of two sets of [[processor register]]s so they could quickly respond to [[interrupt]]s.{{sfn|Faggin|Shima|Ungermann|2007|p=2}}{{efn|This was a fairly common feature of minicomputer designs of the era, and found its way into a number of early microprocessors.}} Ungerman began the development of a series of related controllers and peripheral chips that would complement the design.{{sfn|Faggin|Shima|Ungermann|2007|p=5}}

Through this period, Shima developed a legendary reputation for being able to convert logic concepts into physical design in realtime; while discussing a proposed feature, he would often interrupt and state how much room that would take on the chip and veto its addition if it was too large.{{sfn|Faggin|Shima|Ungermann|2007|p=19}} The first pass at the design was complete by April 1975. Shima had completed a logic layout by the beginning of May. A second version of the logic design was issued on August 7 and the bus details by September 16. Tape-out was completed in November and converting the tape into a production mask required two more months.{{sfn|Faggin|Shima|Ungermann|2007|p=6}}

Faggin had already started looking for a production partner. By this time, Synertek and [[Mostek]] had both set up the depletion-mode production lines that could be used to produce the design. Having talked to Synertek previously, Faggin approached them first. However, the president of Synertek demanded that the company be given a [[second source]] license, allowing them to sell the design directly. Faggin thought this would mean they could never compete even if they set up their own lines, and the agreement fell through. He then turned to Mostek, who agreed to a term of exclusivity while Zilog got their lines set up, and was eventually given the second source agreement.{{sfn|Faggin|Shima|Ungermann|2007|p=7}}

After considering multiple names for the new company, and finding them so unmemorable they could not recall them even a day later, Faggin and Ungermann were kicking around ideas based on "integrated logic" when Ungermann said, "How about Zilog?" Faggin immediately agreed, stating they could say it was the "last word in integrated logic". When they met the next day and both immediately recalled it, the company had its name.{{sfn|Faggin|Shima|Ungermann|2007|p=17}}