Tape Drive is not working

I am having Adaptec 1520B model scsi adapter. I have connected tanberg TDC 4100 tape drive. While booting scsi bios is detecting the attached tape drive. But whenever i tried to take backup it’s not working. I have downloaded the driver from www.adaptec.com web site for various os like dos,windows and unix. But it’s not happening.

below is my settings for host adapter. In scsi utilities it’s detecting host adapter and tape drive.

I/O port address 340h
IRQ – 11
DMA diabled
Bios addressC80000h

while trying to take backup it’s showing driverfile initiliation failure in dos. In win95 also the same thing. According to their help some bios address or i/o port address is conflict.

How to trouble shott and get things down. Kindlydo the needful at the earliest.