The Taito 'TC0220IOC' is a custom IC manufactured by Taito, used across their arcade hardware (such as Taito Z, F2 and L systems ).It comes in a QFP80 package.
Technically speaking it's an Input/Output (I/O) and reset controller: it manages I/O operations and provides the master reset signal.It's not a ery reliable component, a frequent cause of damage is plugging a JAMMA harness backwards, which can route +12V into the chip and fry it.And if this happens, you’ll end up with a completely dead board in your hands (with no or stuck reset signal output coming from pin 8 of the chip).In this case nothing can be done to by-pass the chip since it handles also some data and address lines from main CPU as you can see from pinout (taken from Final Blow schematics).
The only chance to fix a board with a faulty 'TC0220IOC' would be find a spare part from a donor board but you have to sacrifice a working board most of times.Someone had some luck finding NOS or pulled parts from electronics suppliers but you may risk to get counterfeits, mislabeled chips, or dead-on-arrival components.So, I took into account to study some kind of replacement.As always I do I looked at previous hardware where the functions of this chip were accomplieshed by simple TTLs gates (later they embedded the logics into a single chip).The main obstacle for a replacement of a surface mounted part (QFP80 in this case) is how to interface it on the original fooprint but, like other projects of mine, castellated half holes design was the right solution.The 'hearth' of the reproduction is a little CPLD running the logics I reverse-engineered.
The replacement worked good at first try when I tested it on a Crime City PCB.
Another custom IC preserved and a way to save boards that would otherwise be often beyond repair.
Technically speaking it's an Input/Output (I/O) and reset controller: it manages I/O operations and provides the master reset signal.It's not a ery reliable component, a frequent cause of damage is plugging a JAMMA harness backwards, which can route +12V into the chip and fry it.And if this happens, you’ll end up with a completely dead board in your hands (with no or stuck reset signal output coming from pin 8 of the chip).In this case nothing can be done to by-pass the chip since it handles also some data and address lines from main CPU as you can see from pinout (taken from Final Blow schematics).
The only chance to fix a board with a faulty 'TC0220IOC' would be find a spare part from a donor board but you have to sacrifice a working board most of times.Someone had some luck finding NOS or pulled parts from electronics suppliers but you may risk to get counterfeits, mislabeled chips, or dead-on-arrival components.So, I took into account to study some kind of replacement.As always I do I looked at previous hardware where the functions of this chip were accomplieshed by simple TTLs gates (later they embedded the logics into a single chip).The main obstacle for a replacement of a surface mounted part (QFP80 in this case) is how to interface it on the original fooprint but, like other projects of mine, castellated half holes design was the right solution.The 'hearth' of the reproduction is a little CPLD running the logics I reverse-engineered.
The replacement worked good at first try when I tested it on a Crime City PCB.
Another custom IC preserved and a way to save boards that would otherwise be often beyond repair.