First is MTK-80, and then there is TK-80.
三津原敏パソコンミニシリーズアドバイザー。PasocomMiniプロジェクトの仕掛け人としてパソコン、マイコン黎明期のレジェンド達と日々接しているが、今回の対談は、ひときわ緊張したそうだ[editorial Department]: first of all, please tell me what happened to the development of the microcomputer.
[後藤氏]：半導体黎明期の、昭和42年にNECに入社しました。配属先は電子デバイスグループという、コンデンサからトランジスタまで作っている事業グループ。その設備部で、計測装置を設計調達する部隊です。そこで6年くらい経ったところで、九州日本電気に派遣されました。しかし、赴任して2年目くらいにオイルショックがありまして、仕事が徐々に入ってこなくなり……一時期は、草むしりみたいなことまでやっていました（笑）。<17時を過ぎて就業時間が終わると、Intelのマイクロプロセッサ4004を使ったキットで実験をしていました。高速のテープパンチャーとテープリーダーを作って動かしていたのです。4bitでも、ちゃんとやってくれるんですよ。すると、「今度マイクロプロセッサ8080というのを作って事業をやるが、アプリケーションを作るエンジニアがいないので帰ってこないか？」と（元NEC支配人で、パソコン事業立ち上げの責任者だった）渡辺和也さんから声をかけられて、東京に戻りました。
後藤富雄氏。TK-80をはじめ、PC-8001やPC-8801、PC-100、PCエンジンなどを手掛けた人物。PC-8001では、開発リーダーを務める[editorial Department]: where's Mr. Kato?
[Mr. Kato]: in the 50th year of Showa, I joined NEC. Shortly after the oil crisis, there is no need to come to the company for a month after joining the company. He said to be on standby at home. Because I don't have a job, I can't afford to pay for a month. Usually, the entry time is April 1, but I am April 30 (laughter). The encounter with a microcomputer is the time for college graduates to study. The research was completely different, but occasionally the professor bought a 8008 evaluation board (Intel microprocessor) and a telex version of ASR-33 and asked me to connect it and do something. The manual is only written in English. ASR-33 creaked as he watched the program and tried it over and over again. In a sense, this is a very expensive toy. I touched it for about half a year.
加藤明氏。TK-80やPC-8001、PC-8801の開発を行なう。後に、PC-9821シリーズの開発などにも携わった[Mr. Mizuhara]: take this as an opportunity to become NEC?
[Mr. Kato]: that's not true. I want NEC because I want to build a mainframe computer. But after joining the job, he was assigned the same semiconductor division as Goto. One of the options there is the microprocessor, isn't it the one you used to play with when you were a student?
[Mr. Goto]: before that, let's start from here.
後藤氏が“こっちから”と言って見せてくれたのは、TK-80の前身となったハード。名前はMTK-80で、正式名称は「マイクロコンピュータトレーニングキット80」。TK-80と比べると二回りほど小さく、縦に積んであるのが分かる[Mr. Kato]: MTK-80, about half a year after I joined the club, from the beginning of my business, there was an invitation for the Yokosuka Communication Research Institute (Yokosuka Tongyan) of the Yokosuka commune to make microcomputer textbooks for new staff. Goto and I accepted our own orders and began to make them. I'm in a state where I don't know about it, where Goto is too powerful. If you do this, the key will move, and the LED can display hexadecimal, the idea that.
[Mr. Goto]: that's what I said. Mr. Kato gave it to me. At that time, when I read a magazine such as BYTE Magazine, the ad for KIM-1 appeared (the suite of microprocessors 6502). It seems that LED shows four addresses and two six-digit data. And, when the program starts running, the display disappears, so I don't know what's going on. We, the things that the development tools change must do, the monomer also moves, the program is out of control and the LED lights up, and so on.
[Mr. Mitsuhara]: the design is Mr. Goto, and the production is Mr. Kato?
[Mr. Goto]: the concept was considered by Mr. Goto. After I joined NEC, I studied and developed the microprocessor version 8080 of the evaluation board, but this shape was unexpectedly quickly formed by combining its property with Mr. Goto's architecture.
[Mr. Mizuhara]: do you feel anything in your brain?
[Mr. Kato]: yes, it is. The action is very fast, the idea of the most troublesome keyboard and the scan displayed all have Mr. Goto's idea, and it will be no problem if you put it in the circuit.
[Mr. Mizuhara]: is Mr. Kato also the necessary procedure?
[Mr. Kato]: I wrote about the monitor, but it can't be controlled by the capacity. A guy compressed it, and he shrank it tightly with craftsmanship and put it into the three chips.
[Mr. Goto]: provincial memory has been going on since then. Memory is precious, right? (laughter).
[Mr. Kato]: a reduction of 1 byte is such an accumulation. After all, it is only 756 bytes. It contains all the functions of the 8-bit microcomputer at that time. Usually memory access or ROM access, DMA do or interrupt. As a textbook, it feels good.
[Mr. Mizuhara]: what was the delivery quantity at that time?
[Mr. Kato]: Mr. Goto's memory is 3 or 4. My memory is about 10 sets. Not all of them were handed over to Yokosuka Tongyan, and Yokosuka Tongyan was not bought as a whole, but an order placed by the idea of a research lab. MTK-80 is actually an assembly kit. We bagged the parts.
Mr. Mizuhara: for the sake of a small number of stations, write an instruction manual.
[Mr. Kato]: a logical template was drawn on the checkered paper. By the way, PC-8801 is also hand-painted.
[Mitsu Hara]: after the completion of MTK-80, will it be TK-80 that will turn it into a product?
[Mr. Kato]: that's right. The circuit diagram of TK-80 is basically the same as that of MTK-80.
[Mr. Goto]: I use a sketch to put "CPU here" or an image on the business department of the original printing board: "Please, decorate!" "this is TK-80.
[editorial Department]: how many floors are this?
[Mr. Kato]: two floors on the front and back.
[editorial Department]: it also retains the expansionary production.
[Mr. Kato]: the area here (the vacant part of the square space of the substrate) is an expanded area, which is vacated by accident. What a pity, there is a universal port here. A lot of people have formed an interface, so I think it's very useful.
[Mr. Goto]: what I reflected later on was that I wish I had stood up like a raspberry pie.
