The Frob - Reproducing it.

I know some of you are interested in making clones of The Frob (2600 gamedev system for Apple ][) based on the findings I'm getting from my research work.

I will go ahead and say that it may just be better to make a modern equivalent based on the functional description of the hardware in Chapter 2 of the Frob manual: https://archive.org/details/the-frob-a-connoisseurs-guide/page/n15/mode/2up

Functionally, 4K of SRAM, and two bi-directional 8-bit registers (where they split into read/write addresses on the VCS side), that connect to an EPROM cartridge adapter (socket + 74LS04) for the console, is what's needed.