Hi thanks for your reply, but it's not that either!
verifyroms for saa5050 works:
C:\mame>mame -verifyroms saa5050 saa5050 : saa5050 (960 bytes) - NEEDS REDUMP romset saa5050 is best available
C:\mame>mame -verifyroms bbca romset "bbca" not found!
C:\mame>mame -verifyroms bbcb romset "bbcb" not found!
C:\mame>mame -verifyroms bbcm bbcm : saa5050 (960 bytes) - NEEDS REDUMP romset bbcm is best available 1 romsets found, 1 were OK.
so saa5050 and bbcm are found with -verifyroms, but bbca.zip and bbcb.zip are not. My bbca.zip is correct and contains these files: Testing files from .ZIP: C:\c\roms\bbca.zip Testing: basic2.rom OK Testing: os12.rom OK