Viper Phase 1 Old/New Version Switchable Cartridge

[alamone]

I made a switch to select Old/New version on Viper Phase 1.

Seibu1-4: 27C040 -> 27C801
Seibu5: 27C1024 -> 27C4096 (I did not have any 27C2048 handy)
Seibu6: 27C512 -> 27C010 (Need to tie pins 32 and 30 for VCC)

Youtube video