Deciding on the Specs

The following article by Masaharu Takano is a Oct. 3rd, 2008 reprint of “How the Famicom Was Born – Part 7″ which appeared in the Dec. 19th, 1994 edition of Nikkei Electronics. It was commissioned by Nathan Altice. The names and titles of the businesses and people mentioned in the series are unchanged from how they appeared at the time of the original publication.

Summary

In June of 1982, the development of the Family Computer had begun. Joint LSI development with Ricoh started up despite the lack of an exterior design and concrete look for the product. Ricoh adopted the 6502, an 8-bit microprocessor licensed from Rockwell, for the CPU. This initially caused some confusion for the development staff, accustomed to the Z80 they’d been using to develop arcade machine software. That’s when a new employee with a thorough knowledge of the 6502 was added to the team, which accelerated the speed of development.

Bringing Arcade Machine Specs to the Domestic Console

Donkey Kong Arcade

The designers attempted to develop a domestic game console using the technology of Donkey Kong’s arcade version as a base.

It was June, 1982 that Masayuki Uemura, head of Nintendo Manufacturing Headquarters’ Research & Development 2 (titles omitted below), started on the development of the Famicom. The system’s development code name was the GAMECOM.

Motivated By Coleco’s Products

During the Famicom’s development, Nintendo was sharply aware of one product in particular. This was the ColecoVision belonging to an American firm called Coleco. (Fig. 1) Coleco was a toy manufacturer that produced items such as a portable game console that incorporated fluorescent display tubes. At the time, the Atari 2600 was a hit in North America. (Fig. 2) ColecoVision was developed by Coleco in order to compete with it.

Just before Nintendo started work on the Famicom, Coleco employees visited Nintendo with a prototype ColecoVision in tow. R&D2’s engineers were shocked at seeing smoothly animated graphics for the first time.

Takao Sawano (presently deputy section chief of Nintendo Entertainment Analysis & Development Division 1), a member of the development team and one of the people in charge of software development, brought the ColecoVision home and got his parents to play. Their response was overwhelmingly positive.

Sawano joined Nintendo in 1972 and, together with Uemura, participated in the development of games that utilized specialized LSI chips as part of R&D2. He was then recruited to R&D1, who had their hands full with developing the Game & Watch. However, he returned to Uemura’s side for the Famicom development project.

Sawano’s participation had a significant impact on the Famicom’s specifications. It was he that proposed the D-pad on the controller.

It is often said that the Famicom was modeled on the Atari 2600. Certainly, without Atari‘s success, it’s entirely possible that Nintendo would not have taken the plunge with the development of a domestic game console. However, Uemura states that it was the ColecoVision that technologically spurred him and the ColecoVision he had in mind when considering the image of the product.

Figure 1

Figure 1

The Domestic Console Which Became the Model For the Famicom

The exterior of the ColecoVision, released by Coleco in 1982.

Figure 2

Figure 2

The Domestic Game Console That Hit it Big in North America

Atari’s Atari 2600.

Bringing Arcade Machines to Ricoh

Color TV Game 6, first in a line of domestic game consoles jointly developed by Nintendo and Mitsubishi.

For the first 3 months following June, 1982, the company’s primary goal was to make the LSI chip a reality, disregarding the lack of a concrete product design. Uemura dispatched Katsuya Nakakawa (presently section head of R&D2) and Masahiro Ootake (presently deputy section chief of Nintendo’s Development Technology Division) to Ricoh and began an inquiry into the technical specifications.

The reason they chose semiconductor manufacturer Ricoh was due to an association with the company that carried over from their time developing arcade games, as well as the firm’s own interest in domestic console gaming.

The fact that Hiromitsu Yagi (Japanese only) was one of Ricoh’s supervisors also played a big part. In the latter half of the 70s, Nintendo and Mitsubishi Electronics had jointly developed a game console that featured a built-in specialized LSI chip. Yagi, who had been in charge of the LSI design, later transferred from Mitsubishi to Ricoh.

To decide on the approximate specifications, Nakakawa and Ootake brought the arcade version of Donkey Kong along with them to Ricoh so it could be discussed. They had the idea of using existing domestic consoles like the Atari 2600 as a reference, but the consoles that had been developed up until that point didn’t satisfy Nakakawa and Ootake, who had grown accustomed to the arcade machine screen.

Because they were going to the trouble of developing something completely new, they wanted to create a console that surpassed the Atari 2600 and ColecoVision. For this reason, they decided to develop an image processor with the premise of capturing the existing limits and potential of arcade consoles.

Regardless, they also settled on developing an RGB output image processor at the same time. This way, if the domestic console idea didn’t happen to work out, the technology could be put to use in an arcade machine. Indeed, an arcade console that made use of this chip was also released later on. (Fig. 3)

Figure 3

Figure 3

An Arcade Machine on the Famicom

The Nintendo Vs. System, produced after the release of the Famicom.

Deciding On the 6502 For the CPU

The AIM 65/40
The AIM 65/40, a 1981 microprocessor that made use of the Rockwell 6502.

A vital part of LSI development was the selection of a CPU. At the time, the prevailing opinion within the company was that it wasn’t worth considering a CPU other than the Z80 everyone had grown accustomed to during their time developing arcade games.

However, Ricoh recommended the 6502 they’d licensed from Rockwell. They explained to Nintendo that the size of the 6502’s chip was a quarter of the Z80’s, which would allow the company to put whatever circuits they liked in the remaining space.

Uemura took the following two points into consideration when he decided to adopt the 6502: One, a smaller chip size was more desirable in terms of reducing the price. Two, it would be better to use architecture that wasn’t widespread within Japan in order to avoid other companies imitating their product. In reality, it took around a year for competing toy companies to ascertain the Famicom’s CPU following its release.

Despite this, it was difficult to persuade the staff. There were development tools for the Z80 scattered around the company, but no one was very familiar with the 6502. Uemura instructed Sawano, who had just returned to R&D2 from R&D1, to try it out.

Sawano, in charge of software development, was originally against the idea, but he realized upon attempting to program using the 6502 that it was actually quite compatible when used in tandem with a combined image processor. To borrow a phrase from Sawano, “I realized that this microprocessor had charm.” Uemura managed to succeed in convincing the rest of the development staff, and the decision to use a 6502 for the CPU was set in stone.

However, there was still the drawback of not having any satisfactory development tools. Alongside LSI development, creating these turned out to be a major chore.

The Living Manual Joins the Company

Pilotwings SNES
Shuhei Kato went on to program Pilotwings for the SNES.

In the latter half of 1982, when LSI and tool development got on track, an inquiry began into aspects such as concrete software development and the exterior design of the system.

Pairing the unfamiliar 6502 CPU with the game design process was something that took a lot of effort. Arcade ports such as Donkey Kong were included in the lineup of games to be developed. However, because they couldn’t convert the program, the work required a lot of patience, including tasks such as watching the game screen and measuring the timing of animations with a stop watch.

Despite this, in the spring of 1983, the pace of software development greatly increased. Contributing to its acceleration was Shuhei Kato (presently section head of Nintendo’s R&D3), who’d joined the company that year.

Kato, a member of a microprocessor club in his student days, was well informed about the 6502. In front of the university he attended stood a junk shop that sold items such as old arcade circuit boards. His first encounter with the 6502 came about when he purchased a game circuit board he happened to come across and attempted to mod it into a computer. Kato relied on resources such as magazine articles to help him master programming.

Far from undergoing employment training upon joining Nintendo in April, 1983, Kato found himself lecturing the development staff on the 6502. Everyone was astounded at the sudden arrival of a living manual who was capable of reading software instructions and answering in machine language on the spot.

With another talented member added to the staff, the Famicom’s development was at last about to reach its peak.

This Post Has 4 Comments

  1. Guy DiMedi

    That was a really interesting article, I hope it is just part of a series and that we will be seeing more pieces like this in the near future.

    1. GlitterBerri

      It is, you can read the rest here. Still in progress!

  2. johney

    Today we have compilors wich are able to translate an proccesor languange into another proccesor languange,let’s say z80 into 6502 languange for example.
    Emulators are able to emulate any type proccesor into eachother,aslong the hardware it’s runing on is powerfull enough.
    Sure ,It was a huge challange to port games based on z80 languange into 6502 languange.
    This history page just blowed my mind,pretty interresting.

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