The following article by Masaharu Takano is a Oct. 7th, 2008 reprint of “How the Famicom Was Born – Part 9″ which appeared in the March 27th, 1995 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

Following the release of the Family Computer (Famicom), a new project awaited Nintendo’s hardware engineers. This was the development of the Disk System peripheral, a strategic product created by Nintendo that aimed to replace MASK ROM cartridges, the software format of the day, with floppy disks. Equipped with a newly-developed sound chip, in addition to anti-piracy measures, the system was intended for a November, 1985 release date. However, in only 3 years, Nintendo would once again see the Disk System be eclipsed by the use of MASK ROMs, thanks to an increase in MASK ROM memory capacity

Losing Out to the Increased Capacity of ROM Cartridges

In November, 1985, Nintendo released the Disk System peripheral for the Famicom to the tune of 5000 yen ($50 USD). (Fig. 1) The company aimed to adopt a new software format, switching from MASK ROMs to cheap floppy disks.

At the time of the Disk System’s appearance on the market, the idea was to provide players with game software on individual disks. However, the Disk System was to vanish into obscurity without ever becoming mainstream. Only 3 years after its debut, it had already been eclipsed by the reemergence of MASK ROM cartridges. This was due to the advancements in semiconductor technology which allowed MASK ROMs whose storage capacity exceeded the capacity of disks to be obtained at a moderate price.

Following these events, Nintendo is continuing to focus on using MASK ROM cartridges as their primary software format until the debut of a 64-bit successor to the Super Nintendo, planned to be released at the end of 1995.

Figure 1

Affixed to the Bottom of the System

The exterior of the Disk System, a Famicom peripheral. To use it, one affixes the drive unit to the bottom of the system and hooks up the adapter to the cartridge connectors.

Originating From a Proposal to Use IC Cards

The development of the Disk System was triggered by the idea of using IC cards, a proposal brought over to Nintendo by software developer Hudson. 2 years after the Famicom’s release, and 3,000,000 shipments later, Nintendo found themselves hitting a wall. Would children still be willing to buy 5 or 10 MASK ROM cartridges for 5000 yen ($50 USD) apiece? If Nintendo didn’t continue releasing casual games (eg: puzzle games) at cheap prices, consumers might run out of things to play and start looking elsewhere for entertainment. Nintendo employees were plagued by these concerns.

It was around this time that Hudson brought the concept of using IC cards over to Nintendo. The company explained that IC cards equipped with built-in RAM could be programmed with game software. Players would be able to overwrite their existing cards with new game software using IC card writers installed at retail outlets. This way, Nintendo could sell software without being controlled by the time required to ship MASK ROM cartridges to stores. Moreover, consumers would be able to play new games, all for the price of a rewrite fee.

The Discovery of Quick Disks

Masayuki Uemura (titles omitted), motivated by Hudson’s idea, immediately started development on an IC card system, together with the staff of Nintendo Manufacturing Headquarters’ Research & Development 2. However, they soon changed tack, as the project was hampered by problems, including the expense of IC cards with built-in RAM, and the fact that they would be required to pay royalties to IC card developers.

As long as they found another way to allow players to overwrite software, there was no reason that IC cards had to be used. Uemura, deciding to go another route, happened upon Mitsumi Electric’s Quick Disks, a type of floppy. At the time, Quick Disks were used by the MSX, a home computer.

The total memory capacity of a Quick Disk was 112 kB, including both sides. The MASK ROM cartridges of the time held 32 kB of data. What caught Uemura’s eye was the fact that, at 56 kB, one side of a Quick Disk had enough memory to store an entire piece of game software.

Quick Disks differ from regular floppies in that they read and write data via a spiral continuous linear tracking of the head, thus creating a single spiral track along the disk that resembles a record groove. Even when overwriting individual pieces of data, they follow the entire memory area on the magnetic head. Another characteristic of Quick Disks was the fact that Nintendo was able to repurpose the magnet heads used in tape recorders, driving down the cost of the drive unit. However, it took around 8 seconds for the disks to read and write data.

Conceptualization for the product quickly came together once it was decided to use disks rather than IC cards. The price of the drive unit would be similar to the cost of the Famicom at 15000 yen ($150 USD). The system would offer casual games, geared towards puzzle games and titles based on serial dramas. Disks would cost 2500 yen ($25 USD) apiece. The fee for overwriting a disk with new game software would be 500 yen ($5 USD). Disk writers, rather than card writers, would be installed in retail outlets all over the country. (Fig. 2)

Figure 2

Installing Disk Writers in Stores

Disk Writers were installed at over 3000 stores around the country upon the Disk System’s release.

Installing a New Sound Chip in the Adapter

The Disk System was used by affixing the drive unit to the bottom of the Famicom and connecting the adapter to the ROM cartridge connectors.

The adapter was equipped with modular circuits for writing data to disks, buffer RAM for storing game programs and characters, and a newly developed sound chip.

Simply changing the game format from ROM cartridges to disks elminated the need to do a lot of work on a game’s sound. Previously, 32 kB MASK ROM cartridges would be at full capacity just through the storage of image data and programs, leaving only several hundred bytes that programmers could allocate to background music and sound effects.

Disks, on the other hand, boasted a large amount space for data storage, and were capable of allocating several dozen kilobytes to sound. The focus on sound was an attempt to place higher value on a game’s sound effects and music, something that, until then, had only been seen as an accessory to the game itself. This idea was later incorporated into the design of the Super Nintendo sound chip, which Nintendo codeveloped with Sony.

Engraving the Logo & Eliminating Piracy

Because Quick Disks were easier to copy than MASK ROMs, another point that featured prominently in the development of the Disk System was the question of how to deal with the issue of illegal copying.

First, Nintendo’s engineers applied a trick to ensure that people wouldn’t be able to play games via software copied to regular MSX Quick Disks. Only Nintendo’s disks could be used with a Famicom. To this end, they engraved the disks with a NINTENDO logo, and put a raised logo on the side of the drive unit that would mesh perfectly with the engraved logo on the disks. If the disk logo and the drive unit logo didn’t mesh properly, the system wouldn’t be able to read the disk.

There was also the possibility that released drive units would be used for the manufacture of illegally copied software. To prevent this, the engineers applied functional limitations that ensured the data of one disk couldn’t be read in a single sweep, which a copier would require.

The Very First Title Makes Full Use of the Memory Capacity

Nintendo’s original goal in developing the Disk System was to offer players casual games at low prices. However, once software development began, the staff realized how much more memory capacity they had to work with compared to the MASK ROMs of the time.

The first title compatible with the Disk System was the pinoeering Famicom role-playing game known as The Legend of Zelda. (Fig. 3) Despite its status as the first game released on the Disk System, The Legend of Zelda turned out to be an epic title that made full use of the 256 kB of available memory. Whatever had become of Uemura’s desire to offer players casual games…?

Once the first 256 kB game had been developed, it was hard to go back. The golden age of role-playing games such as Dragon Quest that followed shortly afterward also contributed to the acceleration of game software memory expansion.

Third party developers began switching back to MASK ROM cartridges from disks once MASK ROMs exceeding 256 kilobytes of storage space fell to reasonable prices. Third party interest in the undesirable Disk System, with its low profits, slow access, and 500 yen ($5 USD) rewrite fees, waned quickly.

Famicom games were once again offered on MASK ROM carts. Despite seeing the shipment of over 6,000,000 systems (including Sharp’s Twin Famicom, a combined Disk System and Famicom), the era of the Disk System thus came to a close.

Figure 3

The First Disk System Title

Even the first Disk System title made full use of the 256 kB memory capacity.

The Decision to Use ROM Carts For the SNES

Following the release of the Disk System, R&D2 began planning the Super Nintendo. The concept of putting the game software on disks resurfaced in a proposal to use the 1 MB floppy disks found in still video cameras. However, this idea once again lost out to the increase in MASK ROM memory capacity and fizzled out.

These days, R&D2 is wrestling with the rise of satellite broadcast data. A data broadcast adapter on the SNES has the potential to be an even bigger peripheral than the Disk System. By following in the footsteps of radio broadcasts and broadcasting the essence of game software, it’s possible to connect this new technology with the promotion of ROM cartridge sales.