FME-7 is regular chip used in Sunsoft mapper 69 games, Sunsoft 5B chip is used in Gimmick! cart and contain build-in AY-3 sound chip. But i found Sunsoft 5A chip inside GREMLINS cart... I cannot found any info about it (?)
It's probably either a relabeled FME-7 (an earlier version?) or a functionally similar drop-in replacement. The two appear to be wired identically, and the ROM does use mapper 69.
What are the other two games there? I see one is using a Gremlins board with an FME-7, which leads me to believe that the 5A is just an earlier version.
If I were to guess, I'd say the 5A is an earlier revision of 5B, then later on they dropped the extra sound capabilities with the FME-7. The game in the lower right is Honoo no Doukyuuji - Dodge Danpei if I had to guess. The chips must be pin-compatible, or damn close (I see a jumper wire on Dodge Danpei)
I'm guessing the 5A and FME-7 are the same exact silicon inside, and 5B does some very minor pin shifting and added the YM2149/AY-3-8910-with-divider sound thing in. Since a FME-7 will very happily run Gimmick! if you supply an external AY-3-8910/2/3 or YM2149.
LN