INES Mapper 017

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iNES Mapper 017 denotes ROM images that have been extracted from disk images for the Front Fareast Super Magic Card RAM cartridge. They represent games whose Doctor Header file denotes a Super Magic Card disk (byte $0 bit 7 set, byte $7=$AA). Refer to the Super Magic Card article for details on bankswitching. The Super Magic Card's registers are initialized to:

; Play mode, WRAM bank 0, 1 KiB CHR mode enabled
$4500 = $47 

; PRG memory write-protected, two-screen mirroring
$42FF = $20 | (verticalMirroring? 0x00: 0x10)

; 4M banking mode enabled
$43FC = $00

; Initial PRG register content
$4504 = Number of 8 KiB PRG banks -4
$4505 = Number of 8 KiB PRG banks -3
$4506 = Number of 8 KiB PRG banks -2
$4507 = Number of 8 KiB PRG banks -1 (originally Doctor Header file byte $5)

The iNES header may specify a 512-byte trainer (corresponding to Doctor Header file's byte $0 bit 6 being set). The trainer must be loaded to an address originally denoted by the Doctor Header file's byte $2, and is here denoted by the NES 2.0 submapper. In its presence, instead of jumping to the game's reset vector on a hard reset, trainer offset +$000 must be JMPed to.

Submapper    Trainer load address
 0           $7000
 1           $5D00
 2           $5E00
 3           $5F00

Battery-saving of WRAM content is not supported by any Magic Card model. Hard-resetting a game while restoring previously-saved WRAM content in emulators interferes with the correct operation of the trainer's program.