Sega 315-5660 (FC1004)

ASIC Sega Mega Drive II (Model 2) VA1 — PAL · Mega Drive II

Sega's FC1004-family custom chip: the VDP graphics processor, I/O controller and FM sound in one package.

Find datasheet

IC5 IC7

Other components on Sega Mega Drive II (Model 2) VA1 — PAL

CART1 ENC1 IC1 IC4 IC5 IC6 IC7 OP1 OP2 OSC1 REG1 WRAM

About this component

On most Model 2 boards this one chip replaces three Model 1 parts: the 315-5313 VDP (graphics, plus the SN76489-type PSG), the 315-5433 I/O controller (controller ports, region/version register) and a slightly modified Yamaha YM3438 FM synthesiser, the CMOS successor to the YM2612. It has a working 50 Hz mode for PAL. The two pins that set region and video frequency are tied straight to 5 V or ground on Model 2 boards, so region switch mods need careful trace cutting or pin lifting. No public datasheet exists; a replacement has to come from a donor board (315-5708 is the same design made by Fujitsu). Sources: https://consolemods.org/wiki/Genesis:ASIC_Information , https://consolemods.org/wiki/Genesis:Motherboard_Differences , https://www.copetti.org/writings/consoles/mega-drive-genesis/

Pinout & readings

No pinout or reference readings yet — these show what each pin does and what a healthy part should measure.