Using Toshiba XM3301B scsi cdrom on old MACs...help?

Hi Bought several XM3301B Toshiba CDROM drives very cheap. (I am looking for some caddys by the way...anybody got some they wanna throw out?) Trying to use these on old compact MACs and MAC IIs using Mac OS 7.5.5 Used a driver that sees cdrom drive (icon with scsi id for drive appears on os startup) as soon as iso9660 format cd is inserted, it reports that it cant read the disk, it reports the size of the data used up on disk and asks if I wanna format it or eject it... All support files are in the extensions folder (high sierra, foreign files acces...etc...) I am using a driver that says it supports the xm3301 is the readme file. (something from lacie company...off a www page with older MAC drivers.) I have tried apple generic cdrom support. Does not see the xm3301b. (whats the b for anyways?) I have used a newer Pionner scsi cdrom with pionner driver on the same system with success. The newer pionner drive with same driver/support file does same thing.... This must be something simple I cant see...but I am no MAC OS expert... Thanks for reading Claude