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Darksoft

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THIS IS A REPRODUCTION PROJECT MADE BY @caius ALL INFORMATION HAS BEEN POSTED WITH HIS PERMISION. CREDIT AND MERIT GOES TO HIM.

Have you ever encountered the following scenario on your beloved arcade PCBs?

Konami_051550_broken.jpg


Probably sometimes.The cracked component is silkscreened ‘051550’, maybe now the name tells you something :

051550_good.jpg


It’s a custom IC in SIL package that can be found on countless boards manufactured by Konami (from mid 80s to late 90s).Here’s the pinout taken from a TMNT schematics:

051550_schematics.jpg


As you can see, it performs two functions :

  • master /RESET generation for the whole system and watchdog timer
  • coin counters handling

In the below scan of the “naked” component I have highlighted the part of circuit that handles the coin counters.The other part is the /RESET generation circuit which is built around a power supply monitor IC like the Fujitsu MB3773 :

Konami_051550_decapped.jpg


You can read its datasheet here:

http://www.jammarcade.net/files/Datasheets/MB3773.pdf

In this project I took into account only the /RESET function since it’s the most important and vital, coin counters can be now considered obsolete hence I intentionally omitted the relevant circuit.Anyway, for my repro I wanted to keep the dimensions of the original part:

Konami_051550_reproinstallation.jpg


Here’s final testing on a Lethal Enforcers PCB:

See you all to my next reproduction project!
 
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