HELP!! mkisofs -no-emul-boot has problem !!

hi ALL:

        I'm trying to make a bootable CD, if i make the bootable_cd.ifs an floppy image, following command works:

/opt/bin/mkisofs -c boot.catalog -o /Qtm2.1.1.1.A.iso -b bootable_cd.ifs /new_iso_image

But if bootable_cd.ifs is NOT the size of the floppy, i have to use -no-emul-boot and -boot-load-size 4, the CD doesnt boot, , the problem is bootable_cd.ifs is greater than the size of a floppy, so i can’t make it an floppy image, can someone help???

/opt/bin/mkisofs -c boot.catalog -o /Qtm2.1.1.1.A.iso -b bootable_cd.ifs -no-emul-boot -boot-load-size 4 /new_iso_image