Article View: comp.os.msdos.misc
Article #854Re: Limit on number of files per directory
From: Young
Date: Fri, 27 Jul 1990 22:52
Date: Fri, 27 Jul 1990 22:52
49 lines
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2221 bytes
Limit on Number of Directory Entries
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1. Each directory entry (usually file) requires
32 bytes for sttributes and specifications.
^^^^^^^^
2. One sector usually provides 512 Kbytes.
^^^^^^^^^^
3. Each disk type uses different number of sectors
for directory entry information. High-density
disks use _14 sectors_ (7168 bytes), double-sided
double-density disks use _7 sectors_ (3584 bytes),
and single-sided double-density disks use
_4 sectors_ (2048 bytes), regardless the size
of disk (e.g. 5.25" or 3.5").
Note: In case of double-density 5.25" disks,
both 9 and 8 sector formats use the same
amount of sectors for directory entry
information.
4. Now, one can easily :-) calculate the maximum number
of directory entries:
DSSD (160 or 180 Kbytes) - 64 entries
DSDD (320, 360, 720 Kbytes) - 112 entries
DSHD (1.2 or 1.4 Mbytes) - 224 entries.
5. As Mr. Glenn L. Austin @ Apple Comp. Inc.
(austing@apple.com) posted on 7/26/90,
most hard disks support(ed) up to 512 directory
entires. But, under a DOS 4.xx, the number
may be different. In addition, the number is
dependent on the physical design of a hard disk.
6. Finally, let me quote Mr. Glenn L. Austin's words:
> Don't forget that the Label uses one directory entry,
> two are used for the low-level DOS (xxxIO, xxxDOS),
> one is needed for CONFIG.SYS, one is needed for
> COMMAND.COM (unless you specify otherwise in CONFIG.SYS),
> and one is used for each subdirectory in the root directory.
These are important things that are frequently overlooked.
Young @ the University of Texas at Austin
young@emx.utexas.edu (Arpa/Internet)
BGBG767@UTAIVC (Bitnet)
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!ut-emx!young From: young@ut-emx.UUCP (Young) Newsgroups: comp.os.msdos.misc Subject: Re: Limit on number of files per directory Message-ID: <34573@ut-emx.UUCP> Date: 27 Jul 90 22:52:24 GMT Reply-To: young@ut-emx.UUCP (Young U. Ryu) Organization: UTexas Computation Center, Austin, Texas Lines: 49