User Guide

Ampex 1308911-02 6-11
DD-2 Utilities Manual Pages dd2_format_tape
Initialize Indicates a tape that is initialized but not formatted. The
tape holds only a single group A partition that occupies the
entire tape and is formatted on the fly during I/O operations.
Default element values for the Initialize option are listed
below. A hyphen (-) indicates there is no default and you
must enter a valid value for that element.
volid -
asize 0
acount 1
bsize 0
bcount 0
layout Pack
spacing If field is empty, spacing determined from
cartridge size and drive density
volid The volume ID written to the VFI area on the tape. This is an arbitrary
6-byte value. Each byte can be any value, except all 6 bytes cannot be
binary zero. On input, you can specify the volume ID in one of two
ways:
• You can supply six or fewer printable ASCII characters. If you
supply fewer than six characters, the function left-justifies your input
string and pads the right part of the volume ID with ASCII spaces.
• You can supply a 12-digit hexadecimal number prefixed by 0x. This
number can be any value that is not all zeroes. The command does
not pad your input; you must supply all 12 digits.
Note:Ampex suggest that volume ID be equal to cartridge barcode ID.
asize The size, in physical blocks, of the Group A partitions on the tape.
Minimum partition size is 235 physical blocks. However, you can use
zero to indicate that the partition takes up the remainder of the tape.
Values in the range 1-234 are not allowed. Of the specified size, 35
physical blocks are reserved for system information and therefore not
available for user data, leaving a usable minimum size of 200 physical
blocks (roughly 240 million bytes).
If the format type is Initialize, zero is the only valid value.
acount The number of Group A partitions per partition pattern. This value must
be in the range 1-255.
If the format type is Initialize, one is the only valid value.
bsize The size, in physical blocks, of the Group B partitions on the tape.
Minimum partition size is 235 physical blocks. However, you can use a
zero value here to indicate that the partition takes up the remainder of
the tape. Values in the range 1-234 are not allowed. Of the specified size,