November 2014 – JAMMArcade.net

Rainbow Islands repair log #4

Nov 272014

Another TAITO PCB on the bench.This time we have a Rainbow Islands one:

The first thing I noticed was (dust apart..) the lack of the TC0070RGB module.For the uninitiated this custom in SIL package is a DAC so it converts digital RGB output of the PCB into analog signals.I borrowed this custom from my Bonze Adventure PCB and installed the needed sockets as always.Once powered on the board, I was greeted by a solid black screen so I started investigating.Probing the main 68000 CPU I found there was no clock at all.Main clock is generated by a 16MHz oscillator @X1 and then divided by a near 74LS161 counter.I visually inspected this part of circuit and found this:

Replaced the oscillator gave me a fully working board but then it was time to find a proper replacement for the borrowed TC0070RGB.I knew this custom was reverse-engineered by Macro (thanks to him) some time ago:

https://www.arcades.plus.com/Taito-RGB.html

https://www.arcades.plus.com/Taito-RGB-Instructions.html

So I order a couple of bare PCBs and assembled one:

I can say it works like the original part, no differences at all, I higly recommnend this replacement.

Arduino game cartridge dumping

Arduino Comments Off

Nov 232014

Continuing on from the Gameking post I made yesterday. I have been working with Team Europe recently to help dump some cartridges for inclusion into MESS from the Leapster range of devices.
I adapted my Gameking dumper program a little to be more suited to the Leapster but in doing so I believe it made it more generic and therefore easier to be adapted to other devices too.

First off this program relies heavily on two additional IC’s being used in the circuit. These are 74HC4040‘s.
These chips are binary counters and they are great in the fact that they only require 2 inputs each from the Arduino and they cover 12 address bits out each too. So a simple bit of maths tells us that by using 4 output pins from the Arduino we cover 24 address pins. For those of you that thought my Gameking dumper wasn’t possible due to the low number of pins used on the Arduino then this is the reason why.
They are also good to use as they are both 5v and 3.3v tolerant and as a lot of these cartridges only use 3.3v its ideal.

If you are even just slightly familiar with how to hook up a ROM for reading then you will have no issues in wiring this circuit up.
Here is the circuit drawing made by Team Europe

And here is the circuit

Of course all of this is useless without the Arduino program itself which you can DOWNLOAD HERE
If you use this program for anything useful then please let me know and also please give credit where credit is due.

Thanks to Team Europe too for their testing, feedback and providing the pictures used in this post.
You can visit Team Europe’s blog here https://team-europe.blogspot.co.uk/

Gameking ROMs released

General Comments Off

Nov 222014

The eagle eyed among you may have noticed that I recently released the ROM dumps I made of the Gameking cartridges I own.
Haze has made a start on the driver for this system too but looks like we may need to dump the internal Rom of the Gameking in order to get this to work.

If anyone can supply this we would be very interested in getting hold of it in the hope that emulation will be possible.

Grand Striker 2 human HUM-0003-(A) PLD dumps added

PAL Updates Comments Off

Nov 212014

Luizwt (BRASIL) has sent in 3 PLD dumps from Grand Striker 2.
They are straight dumps from PEEL18CV8 devices so unless you convert them you will need to located these devices in order to use them.
Thanks to Luizwt (BRASIL) for these.

Crime City repair log

PCB Repair Logs, Repair Logs Comments Off

Nov 172014

Another board donated from my arcade operators friends.It’s time for Crime City.

For the uninitiated, Crime City is a beat ’em up developed by TAITO that can be played by one or two players simultaneous.Here are the technical specs of the hardware:

Hardware – Taito System B Hardware
Board Number – K1100470A
Main CPU – 68000 (@ 12 Mhz), Z80 (@ 4 Mhz)
Sound – YM2610 (@ 8 Mhz)
Screen Orientation – Horizontal
Resolution – 320 x 224
Refresh Rate – 60 Hz
Palette Colors- 4096
Players – 2
Buttons – 2
Joystick – 8 way

The board booted fine but I immediately noticed that there was no sound at all except for some scratching noises.Besides, some colours were wrong and some characters tended to pink compared to the correct ones from MAME (see wheels of car in the picture below, MAME screenshot is on the right) :

As usual I started my troubleshooting with a visual inspection of the PCB and found a broken track on the solderside which I promptly patched with some AWG30 wire:

This fix restored correct colours (the broken track was actually connected to the TAITO ASIC TC0260DAR which is a custom pallette generator and this explained the reason of the fault)

As I said board was silent, no sound at all except for some noise sign that the main MB3735 amplifier was working fine.Digital audio section is made by a Z80 CPU which commands a sound synthesis YM2610 chip.With my logic probe I could verify that all was working fine there so fault was elsewhere.So I started to suspect the YM3016F sound DAC:

Connecting its analog output to an external amplifier produced no sound (while digital input was present).This convinced me to replace it and so sound was fully restored .

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