Z80 CPU (QFP-44)

Co-CPU QFP-44 Sega Mega Drive II (Model 2) VA1 — PAL · Mega Drive II

Z80-compatible 8-bit CPU in a small 44-pin QFP: drives the sound chips and runs Master System games.

Find datasheet

IC1 IC5

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

The Z80 controls the FM and PSG sound from its own 8 KB of RAM (IC5), leaving the 68000 free for the game. With a Power Base Converter it becomes the main CPU for Master System games. Model 2 boards moved the Z80 from the Model 1's DIP-40 into this much smaller QFP, so the DIP-40 pin table on the original Mega Drive page doesn't apply. If music is missing but some sound effects still play, suspect the Z80, its RAM or the bus between them. Part variants: Likely a Toshiba TMPZ84C00AF (CMOS Z80 in a 44-pin QFP) — the chip carries the Toshiba logo, but the marking couldn't be read in the photo. Sources: 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.