VRC VII

VRC VII
Developer:	Konami
Released:	1991-04-??
Type:	Chip
Channels:	1.) FM Synthesis 2.) FM Synthesis 3.) FM Synthesis 4.) FM Synthesis 5.) FM Synthesis 6.) FM Synthesis

The VRC VII, often referred to as the VRC7, is a chip made by Konami and used as a memory mapper and audio expander for their Nintendo Entertainment System games. This is the 7th virtual ROM controller Konami made, and it was designed to supplant the aging VRC VI. However, since it was so late in development, it was only used in two games, and only one of them, Lagrange Point (FC), used the chip's additional audio capabilities. It's model number is 053982.

The chips audio capabilities come from a modified YM2413, a bare-bones YM3182, that is integrated into the chip. Games using the VRC II get 6 channels of 2-operator FM Synthesis audio.

This modified YM2413 has 3 fewer channels than the original, no rhythm mode, and different instruments.

Pinout

This ASCII art represents the chip's pinout.

               .---\/---.
    PPU /RD -> | 01  48 | -- NC
    PPU A13 -> | 02  47 | <- M2
        GND -- | 03  46 | -> WRAM /CS
        R/W -> | 04  45 | <- /ROMSEL
       /IRQ <- | 05  44 | -> PRG /CS
  CIRAM A10 <- | 06  43 | -> Audio Out
     CPU D0 -> | 07  42 | -- +5V
     CPU D1 -> | 08  41 | -> CHR A17
     CPU D2 -> | 09  40 | -> CHR A16
     CPU D3 -> | 10  39 | -> CHR A15
     CPU D4 -> | 11  38 | -> CHR A14
     CPU D5 -> | 12  37 | -> CHR A13
     CPU D6 -> | 13  36 | -> CHR A12
     CPU D7 -> | 14  35 | -> CHR A11
        +5V -- | 15  34 | -> CHR A10
     CPU A5 -> | 16  33 | <- PPU A12
 Crystal X2 -- | 17  32 | <- PPU A11
 Crystal X1 -- | 18  31 | <- PPU A10
     CPU An -> | 19  30 | -- +5V
    PRG A13 <- | 20  29 | <- CPU A14
    PRG A14 <- | 21  28 | <- CPU A13
    PRG A15 <- | 22  27 | <- CPU A12
    PRG A16 <- | 23  26 | -> PRG A18
        GND -- | 24  25 | -> PRG A17
               `--------'
 
 01,02: this doesn't make sense; 
        the VRC7 provides none of hardware nametables, control of CIRAM /CE, or CHR /CE.
        maybe pin 48 is {pin1 OR pin2}, i.e. CHR /CE for a 28-pin CHR ROM?
        then why didn't TTA2 use it?
 17,18: missing on TTA2, 3.58MHz ceramic resonator on LP
 19: A3 on TTA2, A4 on LP

Image Gallery

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  The VRC VII chip on a Lagrange Point (FC) game board.

Emulation Status

Some of the more impressive NES emulators emulate this chip accurately, as does FamiTracker.

Links

• wiki.nesdev.com/w/index.php/VRC7_audio - Technical information.
• en.wikipedia.org/wiki/Memory_management_controller - Wikipedia.