
ATAPISCSI(4)              OpenBSD Programmer's Manual             ATAPISCSI(4)

NAME
     atapiscsi - ATAPI<->SCSI adapter

SYNOPSIS
     atapiscsi* at wdc? channel ?
     atapiscsi* at pciide? channel ?
     scsibus* at atapiscsi?

DESCRIPTION
     The atapiscsi driver supports ATAPI (also called IDE) devices such as CD-
     ROMs, ZIP drives, LS-120 floppy drives, and tape drives.  All ATAPI de-
     vices talk a subset of the SCSI protocol.

     The atapiscsi driver acts like a SCSI adapter.  Thus, the ATAPI devices
     connected to the system will appear as SCSI devices.  ATAPI CD-ROMs will
     appear as cd(4) devices, ATAPI tape drives as st(4) devices, and ATAPI
     floppies as sd(4) devices.

     For performance reasons, one should avoid putting an ATAPI device and a
     hard disk on the same cable.  The driver does not support bus release
     and, even if it did, many ATAPI devices do not support it.  There is only
     one command outstanding on a cable at a time.  For example, if a hard
     disk and a CD drive are placed on the same cable, the hard disk requests
     may get queued behind slower CD operations.

SEE ALSO
     cd(4), intro(4), pciide(4), scsi(4), sd(4), st(4), wdc(4)

BUGS
     Slow devices, like tape drives, could do a better job of sharing the
     channel.  For now, we recommend you put the tape device on its own chan-
     nel.

OpenBSD 2.8                      July 25, 1999                               1
