Namco '04XX' reproduction

After the recent reproduction of the Namco '02XX' custom IC I took into account the one marked '04XX ' (where 'XX' digits identifies date/lot production).It has same DIP28 600 mil package but different functions being a motion object controller/scratch RAM to CPU bus interface :

It can be found on these PCBs :

• Dig Dug
• Galaga
• Pacland
• Mappy
• Pole Position
• Super Pac-Man

Replacements of this Namco '04XX' are available in CPLD or FPGA but, as always, I made my own reproduction using a different approach.Bootleg boards came handy for my purpose as they usually re-engineer the functions of custom ICs with common parts.I traced the equivalent circuit by comparing a bootleg to an original board and made a first "quick and dirty" prototype with thru-hole parts just to validate the design:

 It worked flawlessly on all different boards I tried (Dragon Buster, Galaga, Pac-Land and Toypop)

Now that the replacement circuit has been verified I can think about an SMD or even CPLD version of my Namco '04XX' custom IC reproduction.Stay tuned.