HD6301V1



8bit Hitachi microcontroller used for multiplayer communication in cartridges like League Bowling.

Compatible with the Motorola 6803 but has additionnal instructions.

Clocked at 1MHz using the signal (divided by 4 internally).

Datasheet
Official datasheet: []

Code
The HD6301 has an internal 4KB ROM section holding program data.

A dump is available, coming from a prototype Riding Hero cart: (2x overdump) - Credits to NeoTurfMasta

Commented source code (still some work left...):

Another take on it: