8008がDatapoint社の端末製品Datapoint2200に採用されなかった理由
Faggin, Federico(1984) “Interview : Federico Faggin”における証言 – 動作速度が遅かった
Fagginは、Datapoint社のインテリジェント端末をエミューレートするチップとして提供することを目的に開発された8ビットCPUの8008に関して、その動作速度が遅かった(it was slow)ため採用されなかったと証言している。
[出典]Faggin, Federico(1984) “Interview : Federico Faggin,” Computerworld, July 30 1984,p.6
Zaks, R. (禿節史訳,1980)『マイクロプロセッサ』における記述 — 「動作速度が遅かったこと」、および、「バイポーラ素子の低価格の急速な進行」
これに関連してZaksは、同様に8008の動作速度が遅かったが、予想外なことにそれが売れた、という証言をおこなっている。またZaksは、データポイント社はバイポーラ素子の価格低下にともない、インテルが開発した8008ではなく、バイポーラ素子で端末を製造することにしたと述べている。
「その次の重要な出来事は、1972年に、同じくインテル社から最初の汎用8ビットマイクロプロセッサ8008が開発されたことである。その数年前に、デイスプレイ・ターミナル杜(現在のデータポイント社)がワンチップでCRTを制御するモノリシックのプロセッサ開発を要求し、競争の末、ふたつの半導体メーカが開発許可を得た。テキサス インスツルメンツ社とインテル杜である。数ヶ月間の努力の後、テキサス インスツルメンツ社が撤退した。一方、インテル社は開発を続け、ついにデータポイント杜の要求にあう素子を作り上げた。しかし、ただ一点だけ要求を満足させえなかった。動作速度が遅すぎたのである。その上、同じ時期に、パイポーラ素子の価格競争が始まり、どんどん価格が下がってきた。
インテル社が開発したプロセッサの動作速度が適当でなかったことと、バイポーラ素子の価格が非常に安くなったことなどから、データポイント社はバイポーラでその制御装置を作ることに決定した。インテル社には、その開発の結果できた素子が残ったが、その明確な市場はなかった。非常に新しい会社であった当時のインテル社の主力製品はメモリである。そこで、少しでも多くのメモリが売れればよいという仮定のもとに、(しぶしぶ?)この8008を市場に出したが、この設計に関するあらゆる仕事を中止し、開発グループも他の仕事に移り、マイクロプロセッサもこれで終りになるはずであった。
これを作った会社も、その競争相手も、ともに驚いたことには、この新製品(マイクロプロセッサ)が急に売れ始めたのである。」
[出典]Zaks, R. (禿節史訳,1980)『マイクロプロセッサ』マイテック、p.42
8008とDatapoint社の端末製品Datapointとの関係
8008の起源に関するStan Mazorの証言(p.2) - 1969年12月にCTC（Computer Terminal Corporation, 後の Datapoint）のVictor Poorと会い、8ビットコンピュータの開発途中であることを聞いた。それでStan Mazorは、その開発途中のコンピュータに関して3つの案の内の一つとして、マイクロプロセッサを提案した。これは、Stan MazorがTed Hoffと4004マイクロプロセッサの開発作業をした経験の優位性から出たものである。
I met with Victor Poor around Christmas time in December ’69 and asked him what he needed the stack for and he said he was building an 8-bit computer. I asked him a little bit about it, and I had the advantage that I’d been working with Ted Hoff on the 4004 since October (for several months), so the idea of a central processor on a chip was something that we were working on [already]. And I asked him about his computer and how smart it was, and what it had to do. I wrote out in front of him three proposals. One was an 8-bit register set with a stack, and another was a register stack with an arithmetic unit. And then I went on to the third proposal and said, “Well, it’s possible we could do the entire 8-bit CPU on one chip.” Well, he certainly wasn’t about to believe that, but he was interested.
8008の起源に関するStan Mazorの証言(p.2) - 1970年1-2月期にCTCのVictor Poorから、同社のコンピュータの命令セットがわかるプログラミング・マニュアル（アセンブリ言語マニュアル）を受け取った。それにより、4004との連関に関する興味深い事実［4004と同量のレジスター・メモリー］に気がついた。
I said, “But we need to know more about your computer before we could proceed with that.” So in the January/February timeframe, he sent us a programming manual– sort of an assembler language manual disclosing the instruction set of his computer. Ted and I had a look at that and one of the interesting things is,[that] it had about the same amount of register memory as we had in the 4004, an 8-deep stack which is about the same amount of memory that we had in the 4004.
Federico Faggin, Hal Feeney, Ed Gelbach, Ted Hoff, Stan Mazor, Hank Smith(2006) Oral History Panel on the Development and Promotion of the Intel 8008 Microprocessor
http://archive.computerhistory.org/resources/access/text/2012/07/102657982-05-01-acc.pdf
INtelのHal Feeneyは、Datapointが定義した命令セットを、マイクロプロセッサの開発に利用可能なように1970年3月に翻訳した
Federico Faggin: Well, Vic Poor told me that in fact they tried it and it never worked.
House: So then Hal came on the scene. I understand you were hired to develop this chip. Tell us your story, Hal.
Hal Feeney: I got involved in what was [called] the 1201 at that time. It was Intel’s first 8-bit microprocessor and with the 1201 [internal] name. I joined Intel on March 9th of 1970. I remember the date for a variety of reasons, but on March 9th, 1970, I also have the handwritten spec that Stan put together that took the instruction set that Datapoint had defined, translated that into a concept that we could use for developing the microprocessor. So from that concept spec, and from the concept timing diagrams that were there, we looked at the pins that would be needed to communicate with the outside world and went to defining a functional block diagram for the chip itself. We also went into defining what the logic would be to accomplish and set up and decode all of the instructions that were part of the instruction set. So as we went through that process, it took about two months for us to develop the initial preliminary specification and develop the block diagram. And going back to some comments that were made about TI, it was at the same time that TI, based on other knowledge that we’ve had, TI was designing a 3-chip set and were designing a serial processor. Intel’s was a single chip and was a parallel processor. And to that point, CTC, Computer Terminal Corporation at the time before their name was changed to Datapoint, was working with both companies and sharing information back and forth so that they could get the best product that they possibly could. And as it turned out, the Intel product was moving along up through the middle of approximately 1970 where we were finishing all of the functional aspects of the specification, getting the specification approved both internally and then sharing it with CTC. And that carried on up through about July of 1970, and at that point in time, there were some problems. I wasn’t really associated with it from the sales side, but there were some problems with whether the customer really was going to follow on and use the chip or was not going to use the chip. As a result, there was about a six-month hiatus. A little bit of work was done on the chip specification, but about a six-month hiatus in terms of the design itself while we went and did some other work at Intel. I also put in some of my time working with Federico on the 4004 and the 4000 series products.
マイクロプロセッサ市場を創造したのは、8008ではなく、8080である
Fagginによる証言「8080がマイクロプロセッサ市場を実際に創った」（“The 8080 really created the microprocessor market”）
Paul Allenの証言– Fagginの上述の証言を引用するとともに、8080がBASIC-ready microprocessorであることを強調している
Paul Allen(2011) Idea Man: A Memoir by the Cofounder of Microsoft, Portfolio/Penguin
AllenにおけるBASICの重要性認識 — 最初のコンピュータ経験としてのBASIC
“It was plain to me from the outset that we’d use BASIC (Beginner’s All- Purpose Symbolic Instruction Code), the relatively simple language that Bill and I learned back at Lakeside in our first computer experience.“(p.4)
8008でBASICを動作させることの困難性に関する認識 – GatesからAllenへ
“And so I asked Bill, “Why don’t we do a BASIC for the 8008?” He looked at me quizzically and said,“Because it would be dog- slow and pathetic. And BASIC by itself would take up almost all the memory. There’s just not enough horsepower— it would be a waste of time.” After a moment’s reflection, I knew he was probably right.”(p.4)
8008でBASICを動作させることの困難性に関する認識 – GatesからAllenへ
