Konami ‘503’ reproduction

 Reproductions  Comments Off on Konami ‘503’ reproduction
Sep 262018

The Konami ‘503’ is a custom chip we can find on some PCBs from this manufacturer.It comes in a DIP40 package with its part number scratched off in typical Konami style :

You can refer to this spreadsheet (courtesy of user ‘mattosborn’ on KLOV forums) for a list of boards (all with Konami Classic pinout) that carry this custom :


Technically speaking, the IC takes care of part of the sprites handling (along with the other custom ‘502’)  as schematics shows :

We already have a modern replacement of the Konami ‘503’ thanks to the wonderful work of people over FPGAArcade forum, this is the thread of reference :


What I made is a “poor man’s” reproduction of this custom chip with no use of CPLD or other complex programmable logics but I simply re-engineered with surface mounted devices the replacement daughterboard (silkscreened ‘KC001’) that Konami used in place of the IC :

Here’s the result:

It works fine on my Track & Field and Kicker PCBs and should do the same in all other boards that use this custom IC.

 Posted by at 10:08 pm

Vigilante repair log and Irem ‘RGLD8M472J221J’ – ‘RGSD10L471G’ reproduction

 PCB Repair Logs, Reproductions  Comments Off on Vigilante repair log and Irem ‘RGLD8M472J221J’ – ‘RGSD10L471G’ reproduction
Aug 152018

Got this Vigilante PCB (by Irem) in a trade some years ago:

Board was dead, stuck on a purple static screen:

As usually I started my troubleshooting with a visual inspection and noticed severe corrosion in some areas, especially around the 3.579545 MHz oscillator:

Analyzying the main Z80 CPU revealed no clock on pin 6.This signal was present on oscillator output but then was lost when routed to the inverter (a 74LS04 @IC30) :

Replacing the TTL restored clock on Z80 but board was still dead.Probing the /RESET pin 26 with an logic analyzer showed an unhealthy signal, there was no proper transition from LOW to HIGH but only some oscillations :

/RESET signal is generated by the MB3771 voltage monitor @IC31.I promptly replaced it:

In this way proper signal was restored:

But main Z80 was still inactive, data/address busses were silent as well as control lines.This lead me to think the CPU was faulty so I removed it:

Testing it in another board confirmed it was really bad.With a good CPU the board finally booted up but the sprites were mostly absent, I could see only some parts of them randomly flying over the screen:


After some time spent to check different things I pinpointed the fault in a bad interconnect ribbon cable.For safety I replaced both of them:

Board fully working again and a quite enjoyable game added to my collection.

The repair was accomplished but, as always I do, I visually inspected the board looking for some candidate parts for a reproduction and I spotted two possible ones.The first is marked ‘8M472J221J’  (‘RGLD8M472J221J’ on manual parts list)

It’s nothing more than a custom resistor network used for inputs, you can find it also on other Irem hardware like M72, M92 and M107.Here’s snippet from R-Type schematics:

I reproduced it this way  :

The latter, marked ’10L471G’ (‘RGSD10L471G’ on manual parts list)  is interesting since it’s a R2R  resistor ladder used to convert to analog the 5 palette digital bits outputted by the surface mounted ‘KNA91H014’ custom.You will find always three of them (one for each RGB color) coupled to one custom.

Its implementation on schematics:

From my experience and other references too the original part is not really reliable (it will crack or burn) so I reproduced it as well:

Testing both reproductions on the repaired Vigilante PCB:

 Posted by at 11:15 pm

Konami ‘054574’ reproduction

 Reproductions  Comments Off on Konami ‘054574’ reproduction
Jul 202018

The ‘Konami 054574’ can be found on some PCBs from this japanese manufacturer always along with the three RGB DACs ‘054573’ (see past article for this ) so this reproduction is the natural follow up.

It shares the same SIL package and pin counting :

As well as most of the internal circuitry with open collector buffers, R/2R and transistors:

Its functions are not really clear though, for sure it’s connected to the above mentioned ‘054573’ and the ‘054338’ (which is a color mixer for special effects) so possibly it’s a RGB mixer/filter.

I simply reproduced it at ‘low-level’ identifying all the parts with their values and figured out the circuit schematics.Here’s the result .

Testing was successfully carried out on a Wild West C.O.W.Boys of Moo Mesa PCB :

 Posted by at 8:51 pm

Konami ‘007593’ & ‘007327’ reproduction

 Reproductions  Comments Off on Konami ‘007593’ & ‘007327’ reproduction
Jul 142018

The ‘007593’ and ‘007327’ are two custom ICs found on some PCBs manufactured by Konami in end 80s.This should be a complete list:

‘007593’ on :

  • Black Panther
  • Fast Lane
  • Contra / Gryzor
  • Hyper Crash
  • Salamander/Life Force
  • City Bomber
  • Kitten Kaboodle / Nyan Nyan Panic
  • Labyrinth Runner/Trick Trap
  • Vulcan Venture / Gradius 2

‘007327’ on :

  • Combat School /Boot Camp
  • Rock ‘n Rage
  • Jackal/Top Gunner
  • Flak Attack
  • Devil World / Dark Adventure
  • Double Dribble
  • Rack ‘Em Up/The Hustler
  • Haunted Castle
  • Super Contra
  • Battlantis
  • Blades of Steel
  • Ajax
  • MX5000

Both ICs have strong similarities starting with how they appear:

Analogous package apart, they have same function as we can see from schematics:

But the ‘007593’ and ‘007327’ are not simple RGB DAC as  you can think of at first glance but they embed a complete palette color circuitry on a single chip.So not only RAMs but, as you can see, many other ICs in form of bare dies covered by coating as well passive parts :

Therefore, for this reproduction project I used a different approach.I studied previous Konami hardware figuring out how the color palette circuit was engineered without the use of the customs.After drawed my schematics I reproduced the ‘007593’ for first:

Once successful tested,  it was the turn of the similar ‘007327’ :

Testing on their respective boards:

The layout of both reproductions could be surely optimized (with consequent reduction of the size of the board) using moderm complex programmable logics but I’m happy enough with them since my primary goal was to study a working replacement for these two custom ICs which seems quite prone to failure making our beloved PCBs unusable.

 Posted by at 12:11 pm
Jul 132018

Recently I decided to take a look at another custom IC, the Taito ‘PC030CM’:

It’s a 20 pin chip in a brown-ish SIL package used on some PCBs like Arkanoid, Bubble Bobble, Big Event Golf, Tokio/Scramble Formation, Legend of Kage and few other.Like schematics shows, the ‘PC030CM’ handles coin inputs as well counters/lockouts:

If the part fails (most of times it breaks due its fragile nature), the board will no longer boot, an ‘I.O ERROR.’ is all you will get:

For this reproduction project I had no need to inspect or analyze the part but I simply re-engineered,using SMT devices, a replacement board that can be found on some Arkanoid bootlegs:

Then I compared my schematics to work previously done by ‘JROK’ on KLOV forums and, once verified everything, I  designed a proper PCB.Here’s the reproduction how looks fully assembled (I ordered it with red soldermask but manufacturer wrongly made it blue)

For the testing the user ‘manimani’ on Neo-Arcadia forum kindly sold me an original Arkanoid PCB :

The board was missing the ‘PC030CM’ custom :

Some workaround was made in such a way that the board could coin up the same using the SERVICE button instead :

So, this was a perfect platform test for my reproduction which worked fine:

Thanks again to ‘manimani’ and ‘JROK’.See you at my next reproduction project.

 Posted by at 10:07 am