Recent content by caius

If there are jailbars then the problem is in data bus of sprites circuit.Assuming that the object ROM board is good (no broken traces, good ROMS and logics, good connection with motherboard, etc..) you should draw the sprites generation circuit to figure out what processes the data from...

Are the devices 28 pin?if yes, they are 1Mbit MASK ROM with non-JEDEC pinout.You can read them as 27C010 but you have to use an adapter to swap /OE and A16. P.S. Yes, they are 28 pin 1Mbit MASK ROMs, I attach datasheet.

The new design is for the '054986A' only. I did it mainly because the DAC used on this modue (as well as on the '054544') is nowadays hard to find and existing stock are quite expensive.So, I found another type of DAC which is more common and affordable.The new '054986A' uses also a new OP-AMP...

Who among you does not know and has never played Bubble Bobble in his arcade life? Personally I love this game and I was looking for an original board since ages but never been lucky to get one so I always ended up settling for bootlegs.But recently I spotted on eBay a legit PCB from Taito.The...

The PLS153 is not a PAL but a PLA (Programmable Logic Array), it has a different architecture.So you can't use PALTOGAL to convert it to GAL but you need to disassemble it (with JEDUTIL or other tool) and then manually recompile the equations (like Apocalypse did) Just to carify that the dump of...

It's a solution I obviously took into account but then discarded because surface mounted devices are not easily serviceable by intermediate users. Then, you know, we are old school :)

For sale the whole CD-ROM assembly for FM TOWNS Marty console.I no longer need it since I have the DocBrown (v2) ODE inside. I have no means to test it again so I sell it as untested but it was working fine when pulled out.Price is 130 euro including shipping worldwide via UPS carrier (2-3 days...

For those hard of hearing : https://www.arcade-projects.com/threads/thunder-hoop-pcb-help.18083/post-283634

Yes, most of Gaelco PCBs have missing video GPROUND on PIN 14 parts side of the JAMMA edge connector.Try to jumper with a wire this pin 14 to a whatever GROUND pin of JAMMA connector (pin 1-2-27-28 of both sides)

Recently I've been asked to look at the Taito 'PC050CM' in order to study a replacement.It's another custom IC you can find on arcade PCBs from '80 like Rastan, Rainbow Islands, Operation Wolf, Chuka Taisen, Dr. Toppel Tankenkai, Kuri Kinton, Continental Circus and others.The chip has a SIL28...

Thanks for your interest.Please, contact me in private.

The only HxC floppy emulator is not enough for the Marty since you need also to adapt the floppy FFC cable of the Marty to the HxC connector.I made this adapter for first and sold many of them, it was so popular that some poor man ripped off my design (after he bought from me an adapter), now he...

Some years I made some work on the Fujitsu FM Towns Marty, a home video game console released in 1993 by Fujitsu, exclusively for the Japanese market.Specifically I found the way to use a FDD emulator (HxC or Gotek) with this console, you can read my past article here : Using the HxC Floppy...

The bottom video board uses ony two DIP40 custom ICs marked 'KNA6034201' that are indeed like two big counters connected to data lines of the tiles ROMs so they are most likely the cause of your issue judging from how fault appear.I reproduced it years ago while I was fixing my R-Type that...

The litte daughterboards are TTL replacement of the '86S100' custom IC : I reproduced it time ago making two versions (one with SMD TTL, the other with a small CPLD) I think Capcom chose to use TTL replacement for a better reliability (the 86S100 fails quite often).I have both revision of...