April 23, 2000 ASC 4 vax

### 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.

### SEE ALSO

cd(4), ch(4), esp(4), intro(4), scsi(4), sd(4), st(4)

### HISTORY

The asc driver first appeared in NetBSD1.5.