Introduction

This document is intended to reflect the current understanding of Sega's 315-5208, 315-5235, and 315-5365 memory paging chips. These chips are used in a variety commercial Sega Master System (SMS) game cartridges. The hope is that these chips can be used to ease creation of SMS software development cartridges. This document should be considered a work-in-progress.

Information in this document is compiled from postings by Mike G. and Charles Mac Donald on the S8-Dev Forum, and from personal investigations by Zoop and Eric Quinn.

Revision History

Revision 0.03.00: Updated 315-5235 pin-out to include RESET pin. Updated the 315-5365 pin-out diagram with information about the CEx inputs. Color-coded the pins on each pin-out diagram. Added description of the 351-5365 chip. Added Casino Games to 315-5365 sightings list. Submitted to S8-Dev (www.smspower.org/dev) January 27, 2002.

Revision 0.02.00: Updated 315-5235 pin-out to include descriptions for pins 24, 29, and 30. Added R-Type to 315-5235 sightings. Thanks go to Leonard Silva de Oliveira. Submitted to S8-Dev (www.smspower.org/dev) August 29, 2000.

Revision 0.01.00: Added 315-5365 pin-out, corrected name of 315-5265 to 315-5365, and updated "sightings" tables. Submitted to S8-Dev (www.smspower.org/dev) July 11, 2000.

Revision 0.00.00: First version. Submitted to S8-Dev (www.smspower.org/dev) June 17, 2000.

Cartridges and Paging Chips

Cartridges that tend to contain paging chips use a white-colored circuit boards. This information can be used when determining which game cartridges contain a paging chip without actually having to open the cartridge – simply look at the color of the card edge at the bottom of the cartridge. However, a white-colored board is not a guarantee that a cartridge contains a paging chip, plenty of examples to the contrary have been found. Conversely, a brown-colored board also does not imply that a paging chip is not present. Certain games using battery backup RAM contain a paging chips and use a brown circuit board. The "sightings" charts below indicate which color circuit board a cartridge contained. So, for example, if you have The Ninja with a white circuit board, chances are good that the cartridge contains a 315-5208 paging chip.


Examples of white and brown circuit boards (Courtesy Mike G.)

The 315-5208 Paging Chip

The 315-5208 paging chip can handle up to 8 16KByte memory pages, making it suitable for use with 1 Megabit games. The commercial SMS cartridges that use the 315-5208 for paging use a ROM chip with model number 831000. The 831000 is a 28-pin 256K*8 ROM chip.

Replacing a #831000 ROM with an #27010 EPROM

A 28-pin #831000 ROM can be replaced with a #27010 32-pin 1 Megabit EPROM. The following table indicates the correct pin mapping.

831000 ROM Pin27010 EPROM Pin
1-143-16
15-2117-23
23-2825-30
222

Connect pins 1, 31, and 32 of the 27010 EPROM to +5v, and pin 24 to GROUND.


Mike G.'s Megabit EPROM Cartridge using 315-5208 Paging Chip (Courtesy Mike G.)

315-5208 Sightings

The following table lists the names of commercial game cartridges that are known to use the 315-5208 paging chip. However, the list below does not guarantee that every cartridge of a particular title contains a 315-5208 chip. The list only indicates that at least one example of a particular title using a 315-5208 has been found.

GameSizeCircuit Board Color
Action Fighter1 MegabitWhite
Alex Kidd in Miracle World1 MegabitWhite
Astro Warrior1 MegabitWhite
Gangster Town1 MegabitWhite
Ghostbusters1 MegabitBrown
Hang-On/Astro Warrior1 Megabit??
The Ninja1 MegabitWhite
World Grand Prix1 MegabitWhite

The 315-5235 Paging Chip

Currently, it is believed that the 315-5235 paging chip can handle up to 32 16KByte memory pages, making it suitable for use with 1, 2, and 4 Megabit games. Additionally, this chip is believed to contain the logic necessary for handling battery-backup RAM. The fact that this chip is known to appear in a Phantasy Star (4 Megabit Plus) supports these two beliefs.

It is found in some cartridges (see ForumTopic:13031) with two 16-bit ROM chips, using CE1 and CE2 to enable them rather than CE0. The ROMs have the first and second halves of the data respectively.


Three different sized carts all using 315-5235

The following diagram shows the suspected pin-out of the 315-5235.

315-5235 Sightings

The following table lists the names of commercial game cartridges that are known to use the 315-5235 paging chip. However, the list below does not guarantee that every cartridge of a particular title contains a 315-5235 chip. The list only indicates that at least one example of a particular title using a 315-5235 has been found.

GameSizeCircuit Board Color
After Burner4 MegabitBrown
Altered Beast2 Megabit??
Galaxy Force4 MegabitBrown
Golden Axe4 MegabitBrown
Mercs4 MegabitBrown
Monopoly1 Megabit, Battery Back-up RAMWhite
Penguin Land1 Megabit, Battery Back-up RAMWhite
Phantasy Star4 Megabit, Battery Back-up RAMBrown
R-Type4 Megabit??
Rastan2 MegabitBrown
Sagaia2 MegabitBrown
Space Gun4 Megabit??
Space Harrier2 MegabitWhite
Spellcaster4 MegabitBrown

The 315-5365 Paging Chip

The 315-5365 can handle 32 x 16KB ROM pages, giving a total of 512KB addressable space. It supports paging in frames 0 (cartridge address 0x400-0x3FFF), 1 (0x4000-0x7FFF), and 2 (0x8000-0xBFFF). It is unknown whether this chip supports SRAM.


Example of board using the 315-5365, Bubble Bobble (Courtesy Mike G.)

315-5365 Sightings

The following table lists the names of commercial game cartridges that are known to use the 315-5365 paging chip. However, the list below does not guarantee that every cartridge of a particular title contains a 315-5365 chip. The list only indicates that at least one example of a particular title using a 315-5365 has been found.

GameSizeCircuit Board Color
Bubble Bobble2 MegabitBrown
Casino Games2 MegabitBrown
Chase HQ2 MegabitBrown
Operation Wolf2 MegabitBrown
Wonder Boy III: The Dragon's Trap2 MegabitBrown



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