PAL UpdatesComments Off on Thunder Blaster and Rabio Lepus PAL dumps added
Mar292017
Today we have some new PAL dumps from these boards:
Thunder Blaster (japanese release of Lethal Thunder, Irem M92 hardware).Devices were two secured PAL16L8 located on ‘M92-C-B’ ROM board.The one labeled ‘M92-C-2L-‘ @IC7 is present also on all other revision of M92 ROM boards although under different labels.The one labeled ‘M92-C-7H-‘@IC43 is specific to this game.256KB binary PAL dumps has been sent in by ‘robotype’ and I took care of reversing them.Lastly I re-organized all the IREM M92 dumps in the database adding notes about shared PALs and indication of ROM board hardware revision where they come from.
Rabio Lepus (japanese release of Rabbit Punch, Video Systems).Two secured devices dumped and reversed : one PAL16L8 on CPU board and one EPL16P8BP on video board.
All dumps have been successfully tested back on respective PCBs using GAL16V8 targeting devices.
Some months ago I received for a repair this Tatsujin Oh PCB (known outside Japan as Truxton II)
As you can see from the above picture, the custom ‘HK-1000’ (used for inputs) in front of JAMMA edge was missing but this was not the main problem, board won’t sync up:
All the graphics and video timing signal (HSYNC, VSYNC, etc..) are generated by a large surface mounted ASIC (208 pins QFP package) marked ‘GP9001’:
You can find its pinout on page 32 of the Knuckle Bash schematics:
The IC was previously reworked by someone in a bad way, many pins were bridged together, flux residuals were not cleaned.So I decided to remove it :
and solder it again:
Happy with the result I powered up the board again and I was greeted but this static garbage screen:
Probing the main 68000 CPU revealed no activity on data bus.Doing a visual inspection of PCB I found a couple of severed traces on solderside just around the CPU area:
Patching them allowed the board to boot but, obviously, due the lack of the ‘HK-1000’, the game was stuck on a ‘TILT’ error message:
Input check in TEST mode reported ON most of them :
Now some words on the ‘HK-1000’.As said, this custom handles all inputs and it’s has been adopted in later Toaplan PCBs.There are two revisions of it, the early one has a ceramic package and due this nature it’s very prone to damage and failure.This revision is used on Truxton II/Tatsujin Oh and FixEight:
The newer revision is more robust and it’s used on Ghox, Pipi & Bibis:
Back to repair, from available info it seems the functions of this custom can be reproduced using a couple of 74LS240 (actually the custom handles also the coin counters and lockout but we can omit it), this is not a suprise for me since a lot of previous Toaplan boards use same design with these TTLs (see for example Truxton, Wardner, Hellfire and other).Doing some tests with a single 74LS240 I was able to successfully map some inputs turning off the TILT error
This allowed me to enter in game :
Later, owner of the board installed the missing HK-1000 and confirmed the board was perfectly working after my repair:
P.S.
I’m currently drawing schematics for the replacement of the HK-1000 and I will post here my results.Stay tuned.
PAL UpdatesComments Off on Gunbird 2 PAL dump added
Mar182017
I dumped the only PAL from a Gunbird 2 PCB.Original device was a secured PALCE16V8H marked ‘PS5-1’ @U18.Dump has been successfully tested onto a GAL16V8 targeting device.
