E-mu Proteus Keys - sound ROMs on mainboard?

Hello all,
For the E-mu Proteus synths with keyboard (circa 2000-2002) - e.g.
*** PK-6 Proteus Keys
*** XK-6 Xtreme Keys
*** MK-6 Mo’Phatt Keys

These synths require at least 1 Sound ROM (SIMM) to work, correct?
They do not have a “default” set of sound ROMs soldered to the mainboard?

Thanks for reading,

I determined that these require at least 1 sound ROM (SIMM) to function.
No default set is on the mainboard.