Cartridges
MVS cartridges
Early cartridges like Puzzled and NAM1975 used lots of discrete logic chips for banking. These chips were quickly merged in ASICs like NEO-273, NEO-ZMC, NEO-PCM, SNK-9201 and NEO-CMC.
[Super Sidekicks] and [Fatal Fury 2] have a special DIP P ROM banking chip called SNK-9201.
[Garou MOTW] has encrypted code and a NEO-SMA chip.
Some carts like [KOF 98] had Altera MAX CPLDs.
[Thrash Rally], [Riding Hero], and [League Bowling] had HD6301 Hitachi microcontrollers and SN75176 differential bus drivers to communicate point-to-point through 3.5mm jack cables and allow multiplayer games. The AES versions only had one plug.
Pinout.
AES cartridges
Different pinout.