| ASC(4) | Kernel Interfaces Manual (VAX) | ASC(4) | 
NAME
 asc — VAXstation 4000 SCSI controller
SYNOPSIS
 asc* at vsbus? csr 0x200c0080 (VS-4000/60 or VLC)
asc* at vsbus? csr 0x25000080 (VS-4000/9x)
asc* at tc? (Not yet supported)
scsibus* at asc?
DESCRIPTION
 The asc driver provides support for the NCR 53c94-based SCSI host adapter on the VAXstation 4000 series, and for the PMAZ-AA and related TURBOchannel SCSI adapter option boards (also on the VAXstation 4000 series models which include support for the TURBOchannel adapter).
CONFIGURATION
 The 
asc driver supports the following 
flags for use in 
config(1) files:
- 
bits 0-7:
- 
disable disconnect/reselect for the corresponding SCSI target
- 
bits 8-15:
- 
disable synchronous negotiation for SCSI target
“Target” is synonymous with SCSI ID number.
Note that SCSI tape drives should be allowed to perform disconnect/reselect or performance will suffer.
 
HISTORY
 The asc driver first appeared in NetBSD 1.5.