Nintendo Gives you the Power of Flash - Nintendo Power Rewritable Cartridges

Courtesy of Wikipedia, Photo by Muband

Three times Nintendo released a product where you could write new games to existing media. The first was the Famicom Disk System, where users could bring in their disks to Disk Writer kiosks in stores and have new games rewritten to the floppy disks. This system began in 1986 and was modestly successful, newly written games were cheaper than buying either new cartridges or new disk games in boxes. The disk system's popularity waned by the 1990s, but Nintendo revived the concept with the Super Famicom Nintendo Power cartridge in 1997. A few years later they released the Game Boy Nintendo Power cartridge in 2000. They discontinued the service on February 28, 2007. In this article I will discuss how the service worked, how the flash cartridges worked, and how they can be flashed today.

How the Service Worked

Game Selection Kiosk

For the Nintendo Power cartridges, (or as the Japanese may prefer, "Memory Cassettes") retail rewriter kiosks were setup at Lawson's Convenience Stores all across Japan. A user would buy a cartridge, 3,980¥ for Super Famicom and 2,500¥ for Game Boy, which would be empty except for the menu program. Then he would go to a Lawson's store, insert the cartridge into a kiosk and select the game he wanted to purchase through a Loppi-style interface. The interface would allow the customer to select his or her game through a touchscreen and allow him or her to delete games if the cartridge did not have enough space. The kiosk would print out a ticket which he would take to the store clerk and pay for the game. Wrestling With Gaming has a good video showing how this could actually happen in a store and is the source for much of the information in this section.

The price depended on the game, and was usually between 1,000¥ and 2,500¥ yen for Super Famicom games and 800¥ yen to 1,000¥ yen for Game Boy games. The price crept up a little over time. The cashier would then take the cartridge, put it in the writer machine, tell it which game to write with the terminal and when it was done, hand the cartridge back to the customer. The writing process could take up to three minutes. How to play sheets were also available on the store for a small fee or free as PDFs on Nintendo's website.

Later Nintendo offered an online service where you could select the game you wished to write and mail in your cartridge. This would probably only have been practical if you lived in a remote area without a Lawson store nearby.

These might be the most comprehensive lists of games available for the SFC service and the GB service. Games could appear or disappear over time on either service.

The cartridges came in off-white cases and had mostly featureless labels with seven boxes, one for up to the seven games the cartridge could hold. The box had a sheet of labels of different sizes where the owner could write the name of the game(s) on the label and stick the label on the cartridge. The different sized labels would correspond to the different sizes of the games. 

Cover to Nintendo Power Book 1

When you bought a cartridge the menu would initially have a scrolling message translated as "News! This cartridge does not come with a game written to it. Please have a game written to it at a store that offers Nintendo rewriting services."

A special magazine, Nintendo Power Book 1 was available in stores for 380¥. This "how to play" magazine gave the instruction sheets for the first 103 games released for the system and a sticker for each game which could be put on the Nintendo Power cartridge label. These stickers would show the games' title screen. There were also instructions on how the system functioned and a short comic showing how the kiosks in the Lawson stores worked. There were also celebrity interviews, a quiz and a maze page and features on some of the new games for the system like Heisei Shin Onigashima, which was originally a Nintendo Power exclusive (but later released on cartridges) and Doukyuusei 2. There was also a Vol. 0 Book which had fewer games and possibly a Game Boy version of the book.

Super Famicom

The SFC Nintendo Power cartridge contained flash memory, which could be rewritten with new games. The amount of flash memory inside was 32 Megabits/4 Megabytes (MiB). As many games stored games to cartridge RAM, 256 Kilobits/32 Kilobytes (KiB) of battery backed SRAM was also inside the cartridge. Normal SNES games, those without special chips, ranged from 256 KiB to 4 MiB.

The cartridge functioned in two modes. In the first mode, the multi-cart mode the cartridge was split into 8 x 512 KiB banks or "F Blocks". A maximum of seven games could be flashed to the cartridge and selected by a menu which boots when the console was powered on. A game could take one bank, two banks or so on depending on its size. One bank was dedicated to the menu program. The second mode was single-game mode. In this mode, only available to 4MiB games, the whole contents of the flash would be overwritten, including the menu program.

Some SNES games used SRAM, others did not. The 32KiB of SRAM was split into 16 banks or "B Blocks". Those that did normally used either 2KiB, 8KiB or 32KiB of SRAM. Games would take up as many banks as they needed.

SFC Cartridge PCB

If you found a cartridge with Wizardry I-II-III - Story of Llylgamyn on it, that was a 4 MiB/32 KiB game and would be the only game on the cartridge and it would use up all its Flash and SRAM. Games like Super Mario World and F-Zero were 512 KiB games and only required 2 KiB each. Seven such games could comfortably share the cartridge. A game like SimCity, which was a 512KiB/32KiB game, rather restricted one's options as to other games because it took all the SRAM in the cartridge. You could only write ROM only games to the cartridge at that point.

Powering all this multicart functionality was a Mega Chips MX15001. This CPLD would handle all the functions required for multicart usage, including providing gatekeeping access to the flash memory for programming it.

In addition to the game's size and amount of RAM it uses, normal SNES cartridges used one of two types of memory addressing, HiROM or LoROM. LoROM and HiROM games put their ROM in different areas of the memory map. The 65816 SNES CPU had a 24-bit addressing bus, meaning it could address 16 MiB of ROM, RAM and registers. Being an upgraded 6502, the 65816 could address 256 banks of 64 KiB. 

The Nintendo Power banking scheme was not efficient. If a 256 KiB game like Space Invaders was written to the cartridge it would still take up a full F Block even though it only needed half of one. The menu code was not very large, it is only just over 16 KiB but takes up a full 512 KiB F Block. If you wrote a game that was 1.5 MiB or 2.5 MiB, it would take 2 MiB and 3 MiB on the cartridge, respectively.

Game Boy

The GB Nintendo Power cartridge was similar to the SFC cartridge with 8 Megabits/1 MiB of flash memory in 8 banks of 128 KiB and 128KiB of SRAM in 16 banks of 8 KiB. It uses the Mega Chip MX15002. Unlike the SFC, the GB required MBCs to be simulated to access more than 32 KiB of ROM, so the MegaChip simulated the MBC1, MBC2, MBC3 (no RTC) & MBC5 chips. These were the common official GB mappers. The menu program would be written into one flash bank, allowing up to seven games to be flashed onto the cartridge, or a 1 MiB game could be written and take up all the cartridge space. 

Prototype of GB Cartridge PCB

Both Game Boy and Game Boy Color games could be played on the Nintendo Power cartridge. The menu graphics are different on a monochrome system compared to a color system and the tune which plays is also different.

If a GB game contained SRAM, it was usually only 8 KiB. MBC1 could support 32 KiB of SRAM in a special mode, MBC3 always supported up to 32 KiB and MBC5 could support 128 KiB but the Nintendo Power cartridge may have been limited to 32 KiB support per game. MBC2 was a special chip which had a small amount of SRAM built into it, 512 nybbles (4-bits of a byte).

By increasing the amount of SRAM, Nintendo made it much less likely that a user would not be able to write the game combination of his choice due to running out of B Blocks. Game Boy games usually ranged in 32 KiB to 512 KiB but Game Boy Color games could push 2 MiB and 4 MiB. Those games would not fit on this cartridge.

Exclusives

The Nintendo Power service provided an opportunity for Japanese gamers to play games that were not released on standalone cartridges.

SFC Exclusives

Columns
Derby Stallion 98
Doukyuusei 2
Dr. Mario

Famicom Bunko - Hajimari no Mori
Genjuu Ryodan
Metal Slader Glory - Director's Cut
Oekaki Logic 1

Oekaki Logic 2
Picross NP Vol. 1

Picross NP Vol. 2

Picross NP Vol. 3

Picross NP Vol. 4

Picross NP Vol. 5

Picross NP Vol. 6

Picross NP Vol. 7

Picross NP Vol. 8

Picross NP Vol. 9

Power Lode Runner
Ring ni Kakero
Super Famicom Wars
Super Family Gelaende
Super Punch-Out!!
Tamagotch Town

Wizardry I-II-III - Story of Llylgamyn
Zootto Mahjong!

This list includes games that were released elsewhere in the world, like Super Punch-Out!! and Dr. Mario (in Tetris & Dr. Mario) but not in Japan as retail cartridges.

At least one game, Metal Slader Glory - Director's Cut, could be purchased as prewritten to the Nintendo Power cartridge. It uses the standard Nintendo Power cartridge box but it has a big sticker with the game's title on it on the box, a peel-off label with the title which can be applied over the regular Nintendo Power cartridge label and a real manual for the game.

GB Exclusives

Balloon Fight GB

Batman Beyond - Return of the Joker

Daikatana GB

Game Boy Gallery 2 (Color)*

Jeremy McGrath Supercross 2000*

Karamuchou wa Oosawagi! - Okawari!

Kawa no Nushi Tsuri 4*

Koguru Guruguru - Guruguru to Nakayoshi

Loppi Puzzle Magazine - Hirameku Puzzle Dai-2-gou

Loppi Puzzle Magazine - Hirameku Puzzle Dai-3-gou

Loppi Puzzle Magazine - Hirameku Puzzle Soukangou

Loppi Puzzle Magazine - Kangaeru Puzzle Dai-2-gou

Loppi Puzzle Magazine - Kangaeru Puzzle Dai-3-gou

Loppi Puzzle Magazine - Kangaeru Puzzle Soukangou

Mr. Driller

Naminori Yarou!

Super Mario Bros. Deluxe

Taisen Tsumeshougi

Xtreme Wheels*

All the Game Boy exclusives are Color-supporting or Color-only games. Not all of these games have been known to have been released. Some of them were only discovered in the huge Nintendo Leak from a few years back. They are given the * above. Nintendo appears only to have offered the monochrome version of Game Boy Gallery 2.

Super Mario Bros. Deluxe was supposed to be the prestige release for the new service, which was originally intended to be launched on November 1, 1999. Delays caused by the 1999 Jiji Earthquake disrupted production of the GB Nintendo Power flash carts and delayed their release until March 1, 2000. It was the most written game to the cartridge in the first half of 2000, followed by The Legend of Zelda DX, Kirby's Dream Land 2, Kirby's Dream Land and Metroid II.

Karamuchou wa Oosawagi! - Okawari! was advertised as an exclusive and cost 1,500¥, significantly more than almost any other game writable to a GB Nintendo Power cartridge.

Writing to Nintendo Power Cartridges

No Game

It took the community a long time to figure out how to write to the flash carts. Nintendo used special flash chips from Macronix with their own programming protocols. These had to be reverse engineered and the Mega Chips did not yield their gatekeeping accessing secrets easily.

There are actually two of these Macronix chips in the SFC cartridge, each 2 MiB and they each have a hidden sector. The PCB has space for a third flash chip. There is a single Macronix flash chip in the GB cartridge and it also has a hidden sector. A hidden sector is 256 bytes and contains the mapping information to tell the Mega Chip how large the game is, how much SRAM it requires, where the game is stored in the flash and where its SRAM is assigned, if any. The GB Map also tells the Mega Chip which MBC to simulate if it uses one. Th SNES Map tells the Mega Chip whether a game uses HiROM or LoROM. Full flash size games put additional information in this space but it is not necessary for the functionality.

Games Added with SF Binary Maker

The Sanni Open Source Cartridge Reader can write both SFC and GB Nintendo Power cartridges. The InsideGadgets GBxCart RW and the Joey Jr. from BennVenn can also write the GB Nintendo Power cartridge.

In order to write games to either cartridge you will first need a special mapping program to create a binary with a MAP file so the cartridge can find a game at the right memory offset. There is one program for SFC Nintendo Power carts  and another for GB Nintendo Power carts. The program can also generate a MAP for a single ROM written to the cartridge.

The SFC binary will ask if the game is a HiROM or a LoROM cart. Run the game in bsnes and you will see its mapping in the Manifest Viewer, or use Superfamicom.org

You will also need the correct menu ROM. No-intro has them for the SFC, "Nintendo Power Menu Program (Japan) (NP).sfc" and "Nintendo Power Menu Program (Japan) (Rev 1) (NP).sfc" are their names. No-intro has the GB Nintendo Power menu ROM as "GB Memory Multi Menu.gbc" Rename them to "menu.sfc" and "menu.gbc" and put them in the same directory as the binary generator program is located.

Games Found on Prototype Carts

One curious thing is that Nintendo allowed a game to use its own custom bitmap to display its game name in the menu. The bitmap data is stored in the menu's F Block as the game is written to the cartridge. The binary generators allow you to use your own font. The Nintendo Power cartridge writer can also change the scrolling message.

If you see a SFC/GB cartridge with only one game, no menu and that game is less than 4 MiB/1 MiB in size, then you should know that cartridge was written through an unofficial device.

If you buy a Nintendo Power cartridge, make sure to dump the menu as it came on the cartridge before writing new games to it if you ever wish to restore the cartridge to its pristine state.