Although this is a bootleg it follows the original PCB closely.
Couple of easy fixes on this one.
First a character issue and second a sound issue.
As you can see in the video above, the screen is filled with “A”s and none of the text is correct
There is a seperate EPROM used for characters on this game.
Pulling this and reading back with my programmer yielded a valid dump for Black Tiger.
Checking the adjacent associated 74LS273’s and 74LS245 showed I had at least one pin floating.
I traced this back to a nearby TMM2016 which had D7 floating.
Replacing this fixed the screen
The sound issue was even easier. The sound program EPROM was completely smashed. Replacing it fixed the issue.
ReproductionsComments Off on Taito MB112S146 custom reproduction
Jun122018
Recently I have been working on reproducing the MB112S146 custom chip for my friend BanjoGuyOllie.
This module is found on Arkanoid, Darius and probably some other titles too.
This has now been done and is available in the downloads section. It required the adapter board from ColinD but I will soon compile for MikeJ’s module too.
So far its only tested on Arkanoid but probably will never get a chance to test on other hardware.
The PLD Archive is currently in the process of being moved to a new wiki.
There may be a delay is adding new files while the wiki get populated. This is currently over half way done but the process is long and tedious bear with us.
In addition to the normal PLD files there is also scope to add more detail and pictures so if anyone has any good quality PCB pictures or extra information like missing PLD IC location details or names then please let us know.
ReproductionsComments Off on Seibu ‘HB-45A’ reproduction
Jun082018
The ‘HB-45A’ is a custom IC used on some PCBs manufactured by Seibu like Raiden II/DX, Zero Team.It can be considered an evolution of the ‘HB-41’ that we already treated in a past article:
It shares the same 20 pin SIL package embedding most of the analog sound system.Its function is to mix and pre-amplify both music and sound FXs :
Here’s how it look “naked” of its external coating:
Design is almost identical to its predecessor with the presence of two OP-AMPs (a dual and a quad one) although they operate from a single supply (+12V) and not dual (+5V/-5V) like the ‘HB-41’.All other components are ceramic/tantalum capacitors and resistors (surface mounted and printed film ones) which are part of the application circuit of the two OP-AMPs
It took some time to draw schematics not without some difficulty due the presence of some hidden printed film resistors located under the quad OP-AMP:
Schematics were then routed to a PCB which looked pretty good on a 3D preview :
The real thing assembled in all its parts :
For a while I was not able to test this reproduction due the lack of a working PCB (the “decapped” original part was taken from a dead board) until the user ‘opt2not’ from Arcade Projects and KLOV forums kindly volunteered.The test platform was his working Raiden DX PCB.He first removed the original ‘HB-45A’ in a very clean way (he used an Hakko FR-300 desoldering gun)
Installed some female 2.54mm round machined headers:
Lastly the reproduction fitted onto the board:
Then he made recordings of audio of both original custom and reproduction redirecting it to a PC from a HAS supergun using a SPDIF breakout from the SCART connection.
Here ‘s capture using the original HB-45A:
Here’s the one using my reproduction:
Comparing the music and FXs at the beginning and end of the recordings sound identical.No differences in quality can be noticed (the slight background noise is normal when there is silence).
For this successful reproduction project I would like to thank again ‘opt2not’ for his precious testing and all material (pictures and audio captures) he provided me.I recommend you to check out his blog :
