While the other boards in Nintendo's naming system have documented differences, the SxROM board series is puzzling. There are a lot of boards, someused in one game, others used in a few and one used in 100 games. While some of these boards have been identified, others have not.
Now, some boards have 32 pin ROMs, others have only 28 pin ROMs. For Program ROM, a 28 pin socket can house a 128KB ROM or lower. But for a Character ROM, a 28 pin socket can only house a 64KB or lower ROM. 32 pin sockets can house 256KB PRG ROMs and 128KB CHR ROMs.
SAROM
128KB PRG ROM (28 pin) (64KB Max)
64KB CHR ROM (28 pin) (16KB Max)
8KB WRAM
battery
SBROM
128KB PRG ROM (28 pin) (64KB Max)
64KB CHR ROM (28 pin) (32KB Max)
SCROM
128KB PRG ROM (28 pin)
128KB CHR ROM (32 pin)
SC1ROM
128KB PRG ROM (28 pin) (64KB Max)
128KB CHR ROM (28 pin)
74LS32
SEROM - How does this differ from SBROM?
128KB PRG ROM (28 pin) (32KB Max)
64KB CHR ROM (28 pin) (32KB Max)
SFROM
256KB PRG ROM (28 pin ROM/32 pin socket)
64KB CHR ROM (28 pin)
SGROM
256KB PRG ROM (128KB ROM 28 pin/32 pin socket)
8KB CHR RAM
SHROM
128KB PRG ROM (28 pin) (32KB Max)
128KB CHR ROM (32 pin)
SH1ROM
128KB PRG ROM (28 pin) (32KB Max)
128KB CHR ROM (28 pin)
74LS32
SJROM
256KB PRG ROM
64KB CHR ROM (28 pin)
battery
SKROM
256KB PRG ROM (128KB Max)
128KB CHR ROM
8KB WRAM
battery
SLROM
256KB PRG ROM
128KB CHR ROM
SL1ROM
256KB PRG ROM (128KB Max)
128KB CHR ROM (28 pin)
74LS32
SL2ROM - I dont have this cart, presumably used only in some copies of Blaster Master. Considering Blaster Master is a 128KB/128KB cart, I don't see how this would differ from SL1ROM.
SL3ROM - Again, what is the real difference between this and SL1ROM?
256KB PRG ROM
128KB CHR ROM (28 pin)
74LS32
SLRROM - Is this another extended board? If not, how would it differ from SLROM?
256KB PRG ROM (128KB Max)
128KB CHR ROM
SNROM
256KB PRG ROM
8KB CHR RAM
8KB WRAM
battery
SOROM
256KB PRG ROM
8KB CHR RAM
8KB WRAM x2 (CHR bit used for banking)
battery
SUROM
512KB PRG ROM (CHR bit used for banking)
8KB CHR RAM
8KB WRAM
battery
SVROM - I have an idea which game uses this board. My guess is that the Famicom combo Final Fantasy I + II cart uses it. It probably has two 8KB W-RAMs, both battery backed, so that the games would not overwrite each other's save games. Thus it is a combination of SOROM and SUROM. (The method those boards is mutually exclusive, however.) Otherwise how would you account for the extra large size cart?
Now, some boards have 32 pin ROMs, others have only 28 pin ROMs. For Program ROM, a 28 pin socket can house a 128KB ROM or lower. But for a Character ROM, a 28 pin socket can only house a 64KB or lower ROM. 32 pin sockets can house 256KB PRG ROMs and 128KB CHR ROMs.
SAROM
128KB PRG ROM (28 pin) (64KB Max)
64KB CHR ROM (28 pin) (16KB Max)
8KB WRAM
battery
SBROM
128KB PRG ROM (28 pin) (64KB Max)
64KB CHR ROM (28 pin) (32KB Max)
SCROM
128KB PRG ROM (28 pin)
128KB CHR ROM (32 pin)
SC1ROM
128KB PRG ROM (28 pin) (64KB Max)
128KB CHR ROM (28 pin)
74LS32
SEROM - How does this differ from SBROM?
128KB PRG ROM (28 pin) (32KB Max)
64KB CHR ROM (28 pin) (32KB Max)
SFROM
256KB PRG ROM (28 pin ROM/32 pin socket)
64KB CHR ROM (28 pin)
SGROM
256KB PRG ROM (128KB ROM 28 pin/32 pin socket)
8KB CHR RAM
SHROM
128KB PRG ROM (28 pin) (32KB Max)
128KB CHR ROM (32 pin)
SH1ROM
128KB PRG ROM (28 pin) (32KB Max)
128KB CHR ROM (28 pin)
74LS32
SJROM
256KB PRG ROM
64KB CHR ROM (28 pin)
battery
SKROM
256KB PRG ROM (128KB Max)
128KB CHR ROM
8KB WRAM
battery
SLROM
256KB PRG ROM
128KB CHR ROM
SL1ROM
256KB PRG ROM (128KB Max)
128KB CHR ROM (28 pin)
74LS32
SL2ROM - I dont have this cart, presumably used only in some copies of Blaster Master. Considering Blaster Master is a 128KB/128KB cart, I don't see how this would differ from SL1ROM.
SL3ROM - Again, what is the real difference between this and SL1ROM?
256KB PRG ROM
128KB CHR ROM (28 pin)
74LS32
SLRROM - Is this another extended board? If not, how would it differ from SLROM?
256KB PRG ROM (128KB Max)
128KB CHR ROM
SNROM
256KB PRG ROM
8KB CHR RAM
8KB WRAM
battery
SOROM
256KB PRG ROM
8KB CHR RAM
8KB WRAM x2 (CHR bit used for banking)
battery
SUROM
512KB PRG ROM (CHR bit used for banking)
8KB CHR RAM
8KB WRAM
battery
SVROM - I have an idea which game uses this board. My guess is that the Famicom combo Final Fantasy I + II cart uses it. It probably has two 8KB W-RAMs, both battery backed, so that the games would not overwrite each other's save games. Thus it is a combination of SOROM and SUROM. (The method those boards is mutually exclusive, however.) Otherwise how would you account for the extra large size cart?