3.3 will work but it does not allow any changes Uni bios is not free anyways
The free UNIVERSE BIOS versions below can be used for personal use only, before downloading you must accept and agree to the following terms;
That you own an original NeoGeo MVS, NeoGeo AES or CD system.
The UNIVERSE BIOS will be for your sole personal use only.
Not to distribute the UNIVERSE BIOS in any way (physical or digital).
Not to included the UNIVERSE BIOS in any product that is sold.
Not to sell the UNIVERSE BIOS on EPROM (or any other physical medium).
Not to alter the UNIVERSE BIOS image file in any way.
Not to hold me responsible for any damage caused by using the UNIVERSE BIOS.
I agree to all the above,
Download v4.0 for MVS / AES, Download v3.3 for CD
It's just as illegal as the normal bios to use.. still has copyright snk code in it..