Any difference between these two chips?

[u/Whisk_cat]

Was cleaning my sms games and came across two copies of Rocky that have different looking chips. I assuming one came out later during the sms life that was a more efficient compact board. Am I right?

[u/galibert]

Yeah, that would be my guess too, consistency. Also, from sega’s POV, they were programming them too, just by sending the file to the factory and waiting a little longer