dbstallman
Member
Recently I was able to aquire a LifeForce PCB with no sound. After getting the sound issues taken care of (dirty pins on the sound ROM), I got to work on my next task : Changing this version of Salamander/LifeForce to a better one.
For those that aren't familiar, this game had some noticable differences in the three versions of the game. In my opinion, the US LifeForce was the least of these with the JP LifeForce edging out the JP Salamander because if it's Gradius style weapon system.
MAME showed six ROMs needing to be replaced for the JP version : one 27C128, one 27C256, two 27C512s and two mask ROMs (TC531000P) that are 28 pin 1Mbit that I cannot find an EPROM equivalent of.
I have a friend in Japan who had mentioned to me a while back that he purchased a US LifeForce and had it converted to the JP version, so I got in touch with him and asked him what he used to replace those two mask ROMs. Unfortunately I had missunderstood his statement, he had converted his board to the JP Salamander, not LifeForce.
Determined, I looked up the pinout for the mask ROM and found that, other than a couple of pins, it was almost the same as a 27C1001/27C010. I have a lot of those sitting around, so I knew I would be able to give it a shot. There was only one problem : the 27C1001s have 32 pins. It was now time to build an adapter. I made a circuit board with a 32 pin socket on the top and two rows of 14 pin extensions on the bottom. I then wired the pins 1 to 1 except for the following : pin 2 on the socket connects to pin 22 on the extension, pin 24 on the socket connects to pin 20 on the extension (pin 22 on the socket also connects to pin 20 on the extension) and pin 32 on the socket connects to pin 28 on the extension. Pins 1, 30 and 31 on the socket are left floating.
When I finished I burned the data and fired up my board with the JP version of LifeForce. Success!
Since I couldn't find this info anywhere else on the net, I figured I would post what I did incase anyone else would like to try the conversion as well.
This is the board with the adapter in the lower left corner :
Here is a close-up of the adapter :
And finally, some pictures of the game in action :
Observe the Gradius wepon system at the bottom of the screen :
For those that aren't familiar, this game had some noticable differences in the three versions of the game. In my opinion, the US LifeForce was the least of these with the JP LifeForce edging out the JP Salamander because if it's Gradius style weapon system.
MAME showed six ROMs needing to be replaced for the JP version : one 27C128, one 27C256, two 27C512s and two mask ROMs (TC531000P) that are 28 pin 1Mbit that I cannot find an EPROM equivalent of.
I have a friend in Japan who had mentioned to me a while back that he purchased a US LifeForce and had it converted to the JP version, so I got in touch with him and asked him what he used to replace those two mask ROMs. Unfortunately I had missunderstood his statement, he had converted his board to the JP Salamander, not LifeForce.
Determined, I looked up the pinout for the mask ROM and found that, other than a couple of pins, it was almost the same as a 27C1001/27C010. I have a lot of those sitting around, so I knew I would be able to give it a shot. There was only one problem : the 27C1001s have 32 pins. It was now time to build an adapter. I made a circuit board with a 32 pin socket on the top and two rows of 14 pin extensions on the bottom. I then wired the pins 1 to 1 except for the following : pin 2 on the socket connects to pin 22 on the extension, pin 24 on the socket connects to pin 20 on the extension (pin 22 on the socket also connects to pin 20 on the extension) and pin 32 on the socket connects to pin 28 on the extension. Pins 1, 30 and 31 on the socket are left floating.
When I finished I burned the data and fired up my board with the JP version of LifeForce. Success!
Since I couldn't find this info anywhere else on the net, I figured I would post what I did incase anyone else would like to try the conversion as well.
This is the board with the adapter in the lower left corner :
Here is a close-up of the adapter :
And finally, some pictures of the game in action :
Observe the Gradius wepon system at the bottom of the screen :
