Older style ecu's run a 27C1028 Chip.

There are some variants to this as the real deal is as rare as rocking horse shit, you can make an adapter board to use two 27C512k chips to mimic the 27C1028 . Its a headache to do it this way and i highly recommened going to someone who can supply real 27C1028's.

Also VOS chips are fairly blind in operation, would be wary about what actual "tune" is inside them. IF you do go down a blind tune map, have it checked out by a workshop of choice as you dont want to spend another 6 -8 k rebuilding a motor for a 250 blind tune.