I'll look and see if I've decapped one yet. I sent Armor Battle to Kevin to see if it could be dumped similarly to HD38750/HD38800, but I don't think he had any luck.
I'm assuming they are MCUs, likely in the HMCS40 family, but the only 2 28-pin parts that I've found have a different pinout: HMCS42/HD38702 and HMCS43S/HD38757.
http://project-megs.blogspot.com/ also shows Tandy Space Shot with HD38138S (S might mean SDIP). And it shows Parker Bros Wild Fire with a TMS1400! I picked up another one recently and it has an AMI S2152 like the first one I got. The first one didn't work and I wasn't able to dump it, but this one works so I'll try to dump it again.
Edit: I had decapped the Sub Chase HD38132 and it is an MCU, but I can't discern 1s and 0s in the ROM. I'll whink it and see if that helps. If not, it's likely implant ROM and I probably won't be able to read it visually. I had also decapped the HD38800 from Kingman, and I can't see those ROM bits, either.
The only text on the Sub Chase die is TD38132.
Also, the S in HD38138S probably doesn't mean SDIP; my Tandy Golf is actually HD38135S and is DIP.