Number And Size Of Diskette Files; Types Of Data Files - IBM 5110 User Manual

Number and Size of Diskette Files
The diskette volume/owner identification (7 sectors) and file header
information are contained on the index cylinder. The remaining
cylinders on each type of diskette can have the following maximum
number of files:
Maximum Number
of Files
Diskette 1
19
Diskette 2 Diskette 20
45 71
Note: For a type 2D diskette, see the disk initialization function in the
IBM 5110 Customer Support Functions Reference Manual, SA21-9311,
for information on how' to get additional file headers.
If you mark the maximum number of files without using all the
available file space, the remaining file space becomes unavailable for
storing data. For example, assume you have an unmarked Diskette 1
with 128 bytes per sector. This diskette has 246,272 bytes available
for storing data; however, you issue the following command:
)Mt~I~K :1.0 :1.9 :/.:1.:1.
L
In this example, diskette drive 1 is used.
The starting file number.
--'-The number of files to be marked.
The size of each file to be marked.
This command marks the diskette with the maximum 19 files. Because
each file is 10K bytes, a maximum of 190K (194,560) bytes of storage
is allocated for the files. Now, if you subtract the allocated diskette
storage from the available diskette file space:
246,272
-194,560
51,712 "'·---For this example, this much diskette storage is
unavailable for you to store data.
Types of Data Files
How to generate the various types of diskette data files is discussed
under Input/Output Control. Two types of data files can cause
diskette file storage to be unavailable for storing data: U (unblocked)
and M (mixed).
Diskette Concepts 91