Viper 60s Theory Of Operation And Maintenance Manual page 114

VIPER SCSI 60, 125 & 150 THEORY OF OPERA TlON AND MAINTENANCE
5.20 ERASE (19h)
The ERASE command erases the tape. To begin erasing, the tape must be positioned at BOT
when the command is issued. Upon completion of the operation, the tape repositions to BOT.
5.20.1 ERASE Command Descriptor Block
BITS 7
I
6
5 4 3
2 1 0
BYTE
0 0 0 0
1
1 0 0 1
1
I
0 0 0
0
0 0
IMMED Long
2 0
0
0 0 0 0 0 0
3 0 0 0
0
•
0
0
0
4 0 0
I
0
0
0
0 0
0
5 X X 0 0 0 0
5.20.2 Command Descriptor Block Field Descriptions
Long
o
5-56
The Long Bit specifies that the entire tape is to be
erased. This bit must be set to one. Viper drive
does not support the short erase option.
The Immediate Bit specifies that status is to be
returned as soon as the ERASE command is
accepted and verified. When this bit is zero,
status is not returned until the tape is Positioned
at BOT.