Another Irem custom IC has been defeated and successfully reproduced.
After the 'KNA70H015(11)' and 'KNA70H016(12)'
Irem 'KNA70H015(11)' and 'KNA70H016(12)' reproduction
I took into account the 'KNA65005-17', a DIP48 part found on M72 and later hardware like M81, M82, M84 and M85 (although with scratched-off part name)
The functions of this custom IC were reversed by analyzing and comparing the signals between original and bootleg hardware.As always I ended up with a prototype made with TTLs gates:
After some tweaking, it worked fine on all PCBs I could try.
Here's testing on R-Type (M72 hardware) and Dragon Breed (M82 conversion)
View: https://www.youtube.com/watch?v=KoCWCHROAiA
View: https://youtu.be/HhcRps53jT4
Since the design has been validated a CPLD version of this TTL reproduction will follow later.And a full re-engineering of the entire Irem PCB is more possible now.
After the 'KNA70H015(11)' and 'KNA70H016(12)'
Irem 'KNA70H015(11)' and 'KNA70H016(12)' reproduction
I took into account the 'KNA65005-17', a DIP48 part found on M72 and later hardware like M81, M82, M84 and M85 (although with scratched-off part name)
The functions of this custom IC were reversed by analyzing and comparing the signals between original and bootleg hardware.As always I ended up with a prototype made with TTLs gates:
After some tweaking, it worked fine on all PCBs I could try.
Here's testing on R-Type (M72 hardware) and Dragon Breed (M82 conversion)
Since the design has been validated a CPLD version of this TTL reproduction will follow later.And a full re-engineering of the entire Irem PCB is more possible now.
Last edited:
