IC: 315-5235

Manufacturer: SEGA

Description: Memory Controller (Paging Chip)

Function: The Master System itself is only capable of accessing 64K of ROM.  The Memory
Controller (Paging Chip) allows it to get past this limitation.  By breaking the ROM up
into 16K chunks known as a "frame", it can "page" through these frames 3 at a time, 
totaling 48K of ROM able to be accessed at one time.  Most of the Sega ROMs contain
this circuit inside them, some do not.  This chip seems to be common with 2 & 4MBit 
games.

Related links: http://www.smspower.org/dev/docs/SMSPagingChips.html

Games that use this part:

Galaxy Force - Sega Master System

After Burner - Sega Master System

Phantasy Star - Sega Master System

Altered Beast - Sega Master System

Spellcaster - Sega Master System

R-Type - Sega Master System