This self-extracting file contains various ASPI*.SYS files for DOS. I successfully installed the ASPI4DOS.SYS and the ASPICD.SYS files in order to be able to use my SCSI hard drives and CD-ROM drive. Also included are AFDISK (Adaptec's SCSI paritioning program) and SCSIFMT, a low level formatter (looks identical to the SCSI Disk utility that the 1542 has in ROM).
Also supported are a ton of other Adaptec SCSI adapters, too many to list here.
Hope ya find this file helpful.