The SIDE-A of the cartridge connector it is front side facing toward the substance.
Being something which was analyzed individually, being to do, it is non guarantee. After turning this schematic to the origin, it does not have responsibility altogether in regard to the trouble which occurs.
You utilized the BSch in compilation in the schematic.
As for the 74LS139N, you think it is recognized that it is used for the selection of the RAM. From the decoding result of the address bus, it can presume the address which is really allotted, don't you think?.
As for read-out of the ROM, just enables the ROM SEL and the RD terminal, address decoding is not done, but it is thought as the thing which has been controlled on M5 itself side.