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Clean up 2nd printing changes

This commit is contained in:
T. Joseph Carter 2017-07-21 08:08:21 -07:00
parent 1e031e6a83
commit 9619707034
1 changed files with 44 additions and 46 deletions
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CHANGES-2nd-printing.txt
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@ -1,11 +1,8 @@
.na
.fi
.ll60
.br
SECOND PRINTING CORRECTIONS SECOND PRINTING CORRECTIONS
.sp3
3-3 3-3
.sp1
Data bits are recorded on the Data bits are recorded on the
diskette in precise intervals. For diskette in precise intervals. For
the purposes of this discussion, the the purposes of this discussion, the
@ -16,34 +13,35 @@ and read back from the diskette takes
the form shown in Figure 3.2. The the form shown in Figure 3.2. The
data pattern shown represents a data pattern shown represents a
binary value of 101. binary value of 101.
.sp3
3-10 3-10
.sp1
at least as long as a typical Gap 3 at least as long as a typical Gap 3
(in practice its length is usually (in practice its length is usually
more than 400 sync bytes, enabling it more than 400 sync bytes, enabling it
to serve as a Gap 3 type for Address to serve as a Gap 3 type for Address
Field number 0 (See Figure 3.7 for Field number 0 (See Figure 3.7 for
clarity). clarity).
.sp3
3-17 3-17
.sp1
page.* page.*
.sp1
diagrammed in Figure 3.21.* diagrammed in Figure 3.21.*
.sp1
*Figures 3.20 and 3.21 present the *Figures 3.20 and 3.21 present the
nibblizing process used by the "6 and nibblizing process used by the "6 and
2" encoding technique. However, the 2" encoding technique. However, the
concept is the same for the "5 and 3" concept is the same for the "5 and 3"
technique. technique.
.sp3
4-17 4-17
.sp1
.nf
occurred. Either a bad checksum was detected on the data in a occurred. Either a bad checksum was detected on the data in a
.fi
.sp1
program given there will read any program given there will read any
track/sector on an unprotected track/sector on an unprotected
diskette into memory, allowing the diskette into memory, allowing the
@ -53,67 +51,68 @@ diskette. Using such a program is
very important when learning about very important when learning about
diskette formats and when fixing diskette formats and when fixing
clobbered data. clobbered data.
.sp3
5-2 5-2
.sp1
The file manager, occupying about The file manager, occupying about
2.8K, is a collection of 2.8K, is a collection of
.bp
5-5 (note correction to correction - first $3F2 is ok) 5-5 (note correction to correction - first $3F2 is ok)
.sp1
.nf
change $3F2 to handle your own RESETs, EOR (exclusive change $3F2 to handle your own RESETs, EOR (exclusive
OR) the new value at $3F3 with a $A5 and store the OR) the new value at $3F3 with a $A5 and store the
result in the power-up byte. result in the power-up byte.
.sp3
.fi
6-5 6-5
.sp1
NOTE: RWTS uses zero-page location NOTE: RWTS uses zero-page location
$48, which is also used by the $48, which is also used by the
APPLE APPLE
monitor to hold the P-register value. monitor to hold the P-register value.
Location $48 should be set to zero Location $48 should be set to zero
after each call to RWTS. after each call to RWTS.
.sp3
6-11 6-11
.sp1
.nf
04/05 - Byte offset of current file position* 04/05 - Byte offset of current file position*
.sp1
.fi
*The current file position is updated *The current file position is updated
to point to the byte following the to point to the byte following the
data read or written. data read or written.
.sp3
8-5 8-5
.sp1
.nf
9E51-9E7F An image of the DOS page 3 jump vector which the 9E51-9E7F An image of the DOS page 3 jump vector which the
above routine copies to $3D0-$3FF. See Chapter 5 for above routine copies to $3D0-$3FF. See Chapter 5 for
a description of its contents. a description of its contents.
.sp3
8-36 8-36
.sp1
B9A0-B9FF SEEKABS routine. B9A0-B9FF SEEKABS routine.
Move disk arm to desired track. Move disk arm to desired track.
Calls arm move delay subroutine ($BA00). Calls arm move delay subroutine ($BA00).
.sp3
8-37 8-37
.sp1
BA00-BA10 Arm move delay subroutine. BA00-BA10 Arm move delay subroutine.
.sp3
A-3 A-3
.sp1
.fi
A diskette containing these five A diskette containing these five
programs is available at a reasonable programs is available at a reasonable
cost directly from Quality Software, cost directly from Quality Software,
6660 Reseda Blvd., Reseda, CA. or 6660 Reseda Blvd., Reseda, CA. or
telephone (213) 344-6599. telephone (213) 344-6599.
.bp
A-12 A-12
.sp1
at location $03 (the volume number at location $03 (the volume number
should match the volume number of the should match the volume number of the
other tracks), and then begin other tracks), and then begin
@ -124,9 +123,8 @@ some reason (eg. physical damage or
problems with the disk drive itself) problems with the disk drive itself)
a return code is printed. For a return code is printed. For
example: example:
.sp3
A-20 A-20
.sp1
.nf
800G (Run the COPY program) 800G (Run the COPY program)
.br