Wednesday, 15 June 2022

Konami '005924' reproduction

 The '005924' is another custom IC from Konami used on arcade PCBs of the mid / late 80s like : 

  • Nemesis hardware
  • Twin 16 hardware
  • Contra
  • Jackal
  • Combat School 
  • WEC Le Mans 24

The chip comes in a ceramic SIL package (11 pin) covered by epoxy :

 

Technically speaking the '005924' is for main CPU reset generation, it acts as watchdog timer and handles coin counters, too.

Recently I have been asked me too look at this chip in order to made a replacement that would help people to fix their boards with faulty '005924'.

An arcade collector friend of mine sent me a chip which he had started decapping (thanks to him!)  :

 


I continued the work and exposed all the ceramic package drawing the schematics at same time.Then I routed a board layout :


Gerger files were sent to manufacturer and, after received the bare PCBs, I populated one with the needed parts :


The test on an Hard Puncher PCB (Twin 16 hardware) was successful, here's a video showing that all functions of original custom chip  (including the watchdog timer feature) were correctly implemented in the reproduction :


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