PAL UpdatesComments Off on Nichibutsu High Rate DVD System PAL dumps added
Aug202017
We have some new dumps from an unusual arcade hardware called High Rate DVD, a DVD-based mahjong system released by Nichibutsu in different volumes, you can read more about here:
256KB binary dumps have been provided by ‘system11’ on Dumping Union list, I took care of reversing them to GAL16V8 targeting devices.Each PAL (identified by a colored stripe or dot on chip) is shared among more than a volume and other Mahjong games too, you will find info on database.Thanks to ‘system11 who also successfully tested dumps back on hardware.
PAL UpdatesComments Off on Cross Blades, Multi Game III, Poosho Poosho PAL dumps added
Aug182017
New PAL dumps today.We have the ones from :
Poosho Poosho.Game was unemulated until I spotted a PCB and bought it thanks to Dumping Union donations.Game will be included in next MAME release.Device was a secured PALCE22V10 which I reversed into a GAL22V10.
Multi Game III.This is an hacked clone of the Nintendo Play-Choice system but hardware is based on the Famicom/Nes home console, you can select 21 games.Devices were three in total, I reversed them in GAL devices ( GAL20V8 and GAL22V10 replacements available for the original PAL20L8)
Cross Blades (Japanese release of Blade Master!).The game runs on Irem M92 hardware, device was a secured PAL16L8 (labeled ‘M92-D-3J-‘ @IC26 on ROM board) which I reversed and successfully tested in a GAL16V8
Received some Irem 92 boardsets mostly for replacing preventively the infamous ELNA brown electrolytic capacitors but two of them were faulty too.
The first was a Cross Blades (japanese version of Blade Master!), board had green ELNA capacitors so no strict need to replace them.
But it suffered from sprites isssue, they were missing some parts:
Pressing the board in the area of ‘NANAO GA22’ custom ASIC restored the sprites :
A closer inspection of this custom revealed three liften pins :
Reflowed them fixed the issue :
The second board was Hook (World version) :
Game booted up but sound was missing, I could hear only a rustling noise.Besides, video had some interferences:
Usually the two issues are strictly related, the cause is some bad electrolytic capacitor in audio circuit which affects video output too.The board mounted ELNA brown capacitors which are well known to age poorly.Sure enough :
The 470uF 25V @C202 was clearly leaking, this capacitor is used as filter for the +12V for the amplifier, this explained the issue.Measuring it out of circuit confirmed it was bad with an increased ESR of 150 Ohm :
I replaced this and all other electrolytic capacitors, this fixed board completely:
Here’s for reference the capacitors list with value and location :
Game was resetting over and over right after the first stating screen without even the possibility to see the diagnostic screen “RAM ROM OK”
The code was running and the watchdog was triggered by some event which I eventually found in a faulty 2114 SRAM @E15 on the video board
Marked in red on the actual pcb:
After changing it, the boot process went on until it displayed RAM and ROM OK but it reset again just before screen with the white grid.
At this time I was complete blind , missing any programming skills I couldn’t check what the code missed to go on.
I had a suspect on the sound part and after checking the clocks on the 8039 MCU I noticed it was completely missing.
The oscillator was working correctly and from the schematics I could see that the clock for the 8039 and the AY is generated using some 4bit binary counters 74ls293, very difficult to find on other boards.
Probing pin 9 of 74ls293@A12 it was stuck high while on pin 10 I had the clock.
I proceeded to test it out of circuit but was tested good.
Not sure about the reliability of the tester, I found a Starforce boot which use one 74ls293 and I installed it in a socket on megazone.
Still reset and no clock from pin 9
The output of the IC@A12 goes to pin 8 of a 74ls240, therefore I decided to test pin 8 of IC @D14 against +5V and it gave me a short.
After changing it the game finally booted without any other faults
This is a quick double repair log of Liquid Kids, a cute platform game release by Taito in 1990 on “F2 System” hardware.
The first PCB:
It played fine but sprites were blocky:
This Taito board like many other uses 4Mbit MASK ROMs to store GFX data, they are well known to be prone to failure.When I went to read the one @IC54 containing sprites data my programmer complained about pin 32:
The device was internally damaged and its dump was bad so I replaced it with a pin to pin compatible 27C400 EPROM, this fixed the issue and board completely.
The second PCB:
It was dead giving just a black screen on power up.Probing the main 68000 CPU revealed the /RESET and /HALT lines were both asserted all the time.The /RESET signal (and /HALT which is derivated from the first) is generated by the usual circuit made of a voltage monitor (in this case an MB3771) and some external components but it’s not directly tied to 68000 but it goes to the custom IC marked ‘TC0220IOC’ (which handles I/O too) which outputs it on its pin 8 :
Lifting this pin confirmed the custom was generating a stuck /RESET signal.Since by-passing the IC is not possible (device is addressable by main CPU) the only choice was replacing it, this is for sure another part very prone to failure, I can say from my experience that when a board that uses it is not booting then this custom is most likely bad :
