User's Manual

AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI) LABELED TAPES
1-10 XEROX LASER PRINTING SYSTEMS TAPE FORMATS MANUAL
HDR2, EOV2, EOF2 labels
These labels are optional. EOF2 and EOV2 may be formatted
differently by different operating systems.
The HDR2 label is optional but is provided automatically by some
operating systems. When used, it must directly follow HDR1. HDR2
generally provides data relating to the physical parameters of the
recorded file, including record format, record length, and block
length. Table 1-4 describes the format of HDR2 labels.
The EOV2 label is optional and is provided automatically by some
operating systems. When used, it must directly follow EOV1. In some
operating systems, EOV2 is identical to HDR2. Table 1-4 describes
the format of these labels. In other operating systems, EOV2 has the
format described in table 1-5. (Refer to next section.)
The EOF2 label is optional but is provided automatically by some
operating systems. When used, it must follow EOF1 directly. In some
operating systems, EOF2 is identical to HDR2. Table 1-4 describes
the format of these labels. In other operating systems, EOF2 has the
format described in table 1-5. (Refer to next section.)
Table 1-4.HDR2, EOV2, and EOF2 labels (ANSI tapes)
Name
Character
position(s)
Field Description
Label identifier 1-3 1 This is the 3-character identifier HDR, EOV, or EOF.
Label number 4 2 This is the number 2.
Record format* 5 3 F = fixed length.
D = variable length with the number of characters in
the record specified in decimal.
U = undefined length.
Block length* 6-10 4 This specifies the maximum number of characters per
block and is a 5-digit numeric field.
For Burroughs large systems ANSI format, this field
represents Burroughs' words (6 characters per word)
rather than a character count.
Record length* 11-15 5 This specifies record length if record format is F,
maximum record length including any count fields if
record format is D or V, or undefined if record format
is undefined. Record length is a 5-digit numeric field.
Reserved for operating
systems
16-49 6 This field may have any of the characters defined in
the ANSI Standard X3.27—1969 as “a” characters.
Block attribute*
(IBM only)
50 7 In the HDR2 label for IBM labels only, this field is the
block attribute.
Buffer offset* 51-52 8 This is a 2-digit numeric field specifying the character
length of any additional field inserted before a data
block (e.g., block length). This length is included in
block length (field 4).
Reserved 53-80 9 Spaces
* Fields 3, 4, 5, 7, and 8 are used by the operating system.