Here's a little guide to deconnect the Chip Select on the game cartridge F-1 Spirit and use it as simple SCC cartridge while keeping the normal use by a switch.

But what's the interest to modify a such beautiful cartridge as F-1 Spirit !?

Let's go back to the beginning ...

We are in the eighties. you are at home and your friend, a MSX fan just like you, is calling you to announce he has finally found Metal Gear 2 English, but this is disk version !! You are very happy and waiting impatiently for your friend ... When he inserts nervously the disk of this great game in your brand new MSX2, you are expecting anything but not that : no any music comes from the machine, only some "beep" and other "beat", it's a great deception ! ...sniff... You have just found that the MSX computer can't produce a correct sound without the SCC cartridge, produced by Konami and dedicated to the audio environment.

But how to get the correct sound?

There are different solutions, more or less risky ...

• Insert a Konami game with the SCC chip in cartridge slot 2 when the MSX is on; very risky option !! I call it the barbaric method.
• Use a Konami cartridge Konami with only the SCC chip, but it's not evident to find this kind of cartridge !!
• Modify one of your Konami cartridges with the SCC chip, making possible to use it to play the game or to produce SCC sounds. We will choose this solution.

Requested hardware

• A F-1 SPIRIT cartridge (in our example).
• A soldering iron
• A fine flat screwdriver .
• A cutter.
• A drilling machine with a drill of 5 or 6mm.
• Some tin.
• A switch with 2 positions (run, stop).
• A resistance 4.7 kOhm (Yellow, Purple, Red).
• Two fine electric wires.
• Much PATIENCE !!

Step 1 : dismounting the cartridge

The cartridge is kept in position at 4 different places by "click" notches, not by screws ! Attention ! Don't break the cartridge !
As showed on the picture on the right, you need to insert delicately a screwdriver to open a little the cartridge and loosen the notches.

Step 2 : modifying the cartridge

You need first to find a location inside the game cartridge to insert the F-1 Spirit/Cartridge SCC switch. The only possible location is on the top right of the plastic case. You need therefore to cut out a plastic piece, but you must avoid to damage the tracks on the back side ! Follow carefully the dotted lines as indicated on the picture.
Then you need to make the required solderings for the implementation of the switch, the wires and the resistance. If you don't know what is a soldering iron, I recommand strongly to rebuild immediately your cartridge and be happy with the "beep" and other "beat", because there's a real risk that you should no more play F-1 Spirit.
You can see here a zoom of the surgical zone, so you can see better the parts that must be soldered. Besides, you need to cut a track with the cutter (link between the ROM and the SCC chip); this track is indicated with a little red arrow on the picture.
Here's the final result you must achieve.

Step 3 : fixing the switch

You are almost at the end of this modification; you have only now to fix the switch on the side of the game cartridge. You need therefore to bore a hole on the ledt side of the cartridge, at the level of the relief with the form of a black disk.
Finally, the home finishing with the addition of a small label to indicate that upwards, a car race is waiting for you and downwards, the SCC cartridge is available for direct using. I must here thank our friend JIPE as he has given me the modification plans and many explanations ! Besides, I must also thank BIfi for his complete guide in English on his website.