WRAM
Sanyo LC331632M-12
32K × 16 pseudo-static RAM (120 ns): the 68000's 64 KB of work RAM.
Other components on Sega Mega Drive II (Model 2) VA1 — PAL
About this component
The main CPU's working memory. VA1 boards combined the VA0's two 68000 RAM chips into this one 16-bit-wide part. Pseudo-static RAM is DRAM with its refresh handled on the chip, so to the board it behaves like ordinary static RAM. A bad work RAM usually gives a black screen or a crash at power-on. 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.