Some years ago I came across to a Rolling Thunder PCB where the custom marked ‘130’ was replaced by a small sub-board (don’t know if made from Namco or bootlegers, from manufacturing I presume the latter)

It seems the original custom is used only on Rolling Thunder PCB where, indeed, you can find it marked as ‘130’ in form of a DIP40 IC:

Whereas on schematics it’s shown as ’41’  like in Metrocross and Baraduke PCBs but it’s not the same and changes from game to game (the custom is basically an address decoder for generating the memory map which, indeed, is specific to a certain game)

After some time I sold the board but before doing this I took a couple of high-res scans of parts and solder side of this replacement PCB with the intention to reproduce it someday in a modern way.That’s what I successfully made recently :

I hope this will help to repair our Rolling Thunder PCBs with a faulty ‘CUS130’ as it seems it’s a quite prone to failure part.

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

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

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:

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 :

You can read its datasheet here:

https://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:

 

Here’s final testing on a Lethal Enforcers PCB:

See you all to my next reproduction project!

They are little but not for this less important so for joke we will call them the “Little Fab Four”.They are four small custom components we often see on our beloved arcade PCBs, this post is about the reproductions I made of them.

 

• Konami ‘007324’

This is a part we can find on Lethal Enforcers PCB (and maybe other but I never encountered it), as schematics show it’s used to interface data busses of the 63C09E main CPU and its program ROM:

Techically speaking it’s a simple resistor pack.Here’s its reproduction

Testing the repro on its own PCB:

 

 

 

• Konami ‘005273/005273A’ – Taito ’48CR-1′ – Technos ‘TRJ-001’                  

I put these three together since they have the same function, design and SIL package.They are 10 pin resistors/capacitors array used for inputs.The bigger resistors (from 1K to 10K Ohm) are used as pull-up of the inputs from edge connector, the smaller ones  (10o-200 Ohm) to route the signal to the remaining inputs circuit (which could be simple logics or ASIC).Lastly the capacitors (ceramic, 100-300 nF) are for filtering possible disturbs.

Here are the repro and their installation:

 

Testing on different PCBs:

 

 

Good things come in small packages!

See you all to my next reproduction project.