mirror of
https://github.com/iKarith/beneath-apple-dos.git
synced 2024-12-21 00:31:36 +00:00
Add chapter 4 to root, fix bit rot
Fixing the bitrot in chapter 4 after moving it meant looking at the OCR'd text on archive.org, which is not good. Here's how not good it was: > A tiL. (be it APPLESOFT, INTEGER, BINARY. or TEXT type) con,i a t a of one > or more sectors containing data. Since the •• ctor i, the smallest unit of > allocatable space on a di s kette, a file will use up at least one sector even > if it i a Ie •• than 256 bytes long; the remainder of the sector is w • • ted. > ThuB , a file containing 400 characters (or bytes) of data will occupy one > entire sector and 144 bytes of another with 112 bytes wasted . Knowing these > facts, one would expect to be able to use up to 16 times 35 times 256 or > 143,360 bytes of space on a diskette for files. Actually, the largest file > that can be stored is about 126,000 bytes long. The reason for this is that > some of the sectors on the di a kette .uat be used for what is called > ·ove[head- . > > <Figure 4.1> > > Overhead sectors contain the iMage of DOS which is 10ad •• 1 when booting the > diskette, a list of the nallles and loes,lollll of the files on the diskette, > and an accounting of the sectors which are free for use with new files or > expon.lu". of existing files. An example of the way DOS uses lectDr. ,. > given in Pigure 4 . 1 . Yeah.... You see why I was so excited by the source text? :)
This commit is contained in:
parent
fe4c578ff9
commit
4461e45278
@ -13,34 +13,24 @@ The way DOS allocates these tracks of
|
||||
sectors is the subject of
|
||||
this chapter.
|
||||
|
||||
A file (be it APPLESOFT,
|
||||
INTEGER, BINARY, or TEXT type)
|
||||
consists of one or more sectors
|
||||
containing data. Since the sector is
|
||||
the smallest unit of allocatable
|
||||
space on a diskette, a file will use
|
||||
up at least one sector even if it is
|
||||
less than 256 bytes long; the
|
||||
remainder of the sector is wasted.
|
||||
Thus, a file containing 400
|
||||
characters (or bytes) of data will
|
||||
occupy one entire sector and 144
|
||||
bytes of another with 112 bytes
|
||||
wasted. Knowing these facts, one
|
||||
would expect to be able to use up to
|
||||
16 times 35 times 256 or
|
||||
143,360 bytes of space on a diskette
|
||||
for files. Actually, the largest file
|
||||
that can be stored is about 126,000
|
||||
bytes long. The reason for this is
|
||||
that some o\x86PL@\x85TCESHWV\x87HK\x86PL@)ALUOCQP@\x85HQUS\x84DB\x85PUCA\x84@JW\x86PODQ\x84LU*FGIH@@\x87\x85HQAUOCGA\x85\x8b\x86\x84hSAVNCGB\x86UCDSHWV+EKKRDMI\x86PL@\x85LIEAC\x85HC\x86`hw\x87POLEO\x84LU+IHGA@A\x84PO@I*EJKSNJC\x86QMA\x87@OVNBSPC\x8a\x87E\x86KLVQ\x85JC\x85QM@)IFIAU\x87DIB\x84HHGGQLIKV\x87HC\x86PL@\x85@NI@U\x87HK*QL@\x85@LUOCQP@\x89\x84DIB\x87EI\x86EEDJPKPNIB\x87HC)RMB\x85VCGPKVW\x26 which are free for use
|
||||
with new files or expansions of
|
||||
existing files. An example of the way
|
||||
DOS uses sectors is given in Figure
|
||||
4.1.
|
||||
A file (be it APPLESOFT, INTEGER, BINARY, or TEXT type) consists of one or more
|
||||
sectors containing data. Since the sector is the smallest unit of allocatable
|
||||
space on a diskette, a file will use up at least one sector even if it is less
|
||||
than 256 bytes long; the remainder of the sector is wasted. Thus, a file
|
||||
containing 400 characters (or bytes) of data will occupy one entire sector and
|
||||
144 bytes of another with 112 bytes wasted. Knowing these facts, one would
|
||||
expect to be able to use up to 16 times 35 times 256 or 143,360 bytes of space
|
||||
on a diskette for files. Actually, the largest file that can be stored is about
|
||||
126,000 bytes long. The reason for this is that some of the sectors on the
|
||||
diskette must be used for what is called "overhead".
|
||||
.sp1
|
||||
*** INSERT FIGURE 4.1 ***
|
||||
.sp1
|
||||
Overhead sectors contain the image of DOS which is 1oaded when booting the
|
||||
diskette, a list of the names and locations of the files on the diskette, and an
|
||||
accounting of the sectors which are free for use with new files or expansions of
|
||||
existing files. An example of the way DOS uses sectors is given in Figure 4.1.
|
||||
|
||||
DISKETTE SPACE ALLOCATION
|
||||
|
||||
The map in Figure 4.1 shows that the
|
Loading…
Reference in New Issue
Block a user