Konami ‘501’ reproduction

The Konami  ‘501’ is one of the many custom ICs you probaby encountered when dealing with PCBs from this manufacturer.Most of times the chip (28 pin 600 mil DIP package) comes with scratched-off part name, sometimes not like on my Rush’n Attack PCB:

It can be found on not so many PCBs like shown on this useful spreadsheet (credits to ‘mattosborn’ on KLOV forums)

https://docs.google.com/spreadsheets/d/1iB9BJaEpAufgKaz758FiDDekUH8JreoTn276yPqD-kk/edit#gid=0

Actually there is already a reproduction of it which uses the ColinD CPLD 28 pin board (based on Altera EPM7064S)  of which ‘Porchy’ wrote the code (available here for download).I simply made what I call a ‘poor man’s’ version using simple surface mounted TTLs gates:

Here’s final testing on the Rush’n Attack PCB: