Cleanup of Chapter 2

ch02.txt

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-CHAPTER 2 - THE EVOLUTION OF DOS
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+## CHAPTER 2 - THE EVOLUTION OF DOS
+
+Since its introduction, Apple DOS has gone through three major versions.  All of
+these versions look very much the same on the surface.  All commands supported
+by DOS 3.3 are also supported in 3.2 and 3.1.  The need for additional versions
+has been more to fix errors in DOS and to make minor enhancements than to
+provide additional functionality.  Only DOS 3.3 has offered any major
+improvement in function; an increase in the number of sectors that will fit on a
+track from 13 to 16.
 
-Since its introduction, Apple DOS has
-gone through three major versions.
-All of these versions look
-very much the same on the surface.
-All commands supported by DOS 3.3
-are also supported in 3.2 and 3.1.
-The need for additional versions has
-been more to fix errors in DOS and to
-make minor enhancements than to
-provide additional functionality.
-Only DOS 3.3 has offered any major
-improvement in function; an increase
-in the number of sectors that will
-fit on a track from 13 to 16.
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 DOS 3   - 29 June 1978
-.br
 DOS 3.1 - 20 July 1978
 
-The first release of DOS was
-apparently a victim of a rush at
-Apple to introduce the DISK II. As
-such, it had a number of bugs. With the
-movement towards the APPLE II PLUS
-and the introduction of the AUTOSTART
-ROM, a new release was needed.
-.sp1
+The first release of DOS was apparently a victim of a rush at Apple to introduce
+the DISK II. As such, it had a number of bugs. With the movement towards the
+APPLE II PLUS and the introduction of the AUTOSTART ROM, a new release was
+needed.
+
 DOS 3.2 - 16 February 1979
 
-Although DOS 3.2 embodied more
-changes from its
-predecessor than any other release of
-DOS, 90% of the basic structure of DOS 3.1
-was retained. The major differences
-between DOS 3.1 and 3.2 and later versions of DOS
-are listed below:
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+Although DOS 3.2 embodied more changes from its predecessor than any other
+release of DOS, 90% of the basic structure of DOS 3.1 was retained. The major
+differences between DOS 3.1 and 3.2 and later versions of DOS are listed below:
 
-- NOMON C,I,O is the initial default
-under DOS 3.2.  MON C,I,O was the
-default under DOS 3.1.
+- NOMON C,I,O is the initial default under DOS 3.2.  MON C,I,O was the default
+  under DOS 3.1.
 
-- Input prompts (>,],*) are echoed
-when MON O is in effect, not under
-MON I as was the case under 3.1.
+- Input prompts (>,],*) are echoed when MON O is in effect, not under MON I as
+  was the case under 3.1.
 
-- When a DOS command was entered from
-the keyboard, DOS executed it and
-then passed a blank followed by a
-carriage return to BASIC under 3.1. Under 3.2
+- When a DOS command was entered from the keyboard, DOS executed it and then
+  passed a blank followed by a carriage return to BASIC under 3.1. Under 3.2
   only a carriage return is passed.
 
-- Under 3.2, certain commands may not
-be entered from the keyboard but may
-only be used within a BASIC program
-(READ, WRITE, POSITION, OPEN,
-APPEND).
+- Under 3.2, certain commands may not be entered from the keyboard but may only
+  be used within a BASIC program (READ, WRITE, POSITION, OPEN, APPEND).
 
-- Under 3.2, when LOADing an APPLESOFT program,
-DOS automatically
-converts from APPLESOFT ROM format to
-APPLESOFT RAM format if the RAM version of
-BASIC is in use and vice versa.
+- Under 3.2, when LOADing an APPLESOFT program, DOS automatically converts from
+  APPLESOFT ROM format to APPLESOFT RAM format if the RAM version of BASIC is in
+  use and vice versa.
 
-- DOS 3.1 could not read lower case
-characters from a text file; DOS 3.2
-can.
+- DOS 3.1 could not read lower case characters from a text file; DOS 3.2 can.
 
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-- Some DOS commands are allowed to
-create a new file, others will not.
-Under DOS 3.1, any reference to a
-file that didn't exist, caused it to
-be created. This forced DOS 3.1 to
-then delete it if a new file was not
-desired. (LOAD XYZ under 3.1 if XYZ
-did not exist, created XYZ, deleted
-XYZ, and then printed the file not
-found error message.) Under 3.2, OPEN
-is allowed to create a file if one
-does not exist, but LOAD may not.
+- Some DOS commands are allowed to create a new file, others will not.  Under
+  DOS 3.1, any reference to a file that didn't exist, caused it to be created.
+  This forced DOS 3.1 to then delete it if a new file was not desired. (LOAD XYZ
+  under 3.1 if XYZ did not exist, created XYZ, deleted XYZ, and then printed the
+  file not found error message.) Under 3.2, OPEN is allowed to create a file if
+  one does not exist, but LOAD may not.
 
-- Under 3.1, exiting to the monitor
-required that the monitor status
-register location ($48) be set to
-zero before reentering DOS. Under DOS
-3.2 this is no longer necessary.
+- Under 3.1, exiting to the monitor required that the monitor status register
+  location ($48) be set to zero before reentering DOS. Under DOS 3.2 this is no
+  longer necessary.
 
-- The Read/Write-Track/Sector (RWTS)
-section of DOS disables interrupts
-while it is executing. Under 3.1,
-RWTS could be interrupted by a
-peripheral while writing to a disk,
-destroying the disk.
+- The Read/Write-Track/Sector (RWTS) section of DOS disables interrupts while it
+  is executing. Under 3.1, RWTS could be interrupted by a peripheral while
+  writing to a disk, destroying the disk.
 
-- The default for the B (byte offset) keyword is 0
-under 3.2.
+- The default for the B (byte offset) keyword is 0 under 3.2.
 
-- DOS was reassembled for 3.2 causing most of
-its interesting locations and
-routines to move slightly. This
-played havoc with user programs and
-utilities which had DOS addresses
-built into them.
+- DOS was reassembled for 3.2 causing most of its interesting locations and
+  routines to move slightly. This played havoc with user programs and utilities
+  which had DOS addresses built into them.
 
-- Additional file types (beyond
-T, I, A, and B) are defined within
-DOS 3.2, although no commands yet
-support them. The new types are S,
-R, a new A, and a new B.
-R has subsequently been used by the
-DOS TOOLKIT for relocatable object
-module assembler files.  At present,
-no other use is made of these
-extra file types.
+- Additional file types (beyond T, I, A, and B) are defined within DOS 3.2,
+  although no commands yet support them. The new types are S, R, a new A, and a
+  new B.  R has subsequently been used by the DOS TOOLKIT for relocatable object
+  module assembler files.  At present, no other use is made of these extra file
+  types.
 
-- Support was added under 3.2 for the
-AUTOSTART ROM.
+- Support was added under 3.2 for the AUTOSTART ROM.
 
-- All files open when a disk full
-condition occurs are closed by DOS
-3.2.
+- All files open when a disk full condition occurs are closed by DOS 3.2.
+
+- As with each new release of DOS, several new programs were added to the master
+  diskette for 3.2. Among these was UPDATE 3.2, a replacement for MASTER.CREATE,
+  the utility for creating master diskettes. UPDATE 3.2 converts a slave into a
+  master and allows the HELLO file to be renamed.
 
-- As with each new release of DOS,
-several new programs were added to
-the master diskette for 3.2. Among
-these was UPDATE 3.2, a replacement
-for MASTER.CREATE, the utility for
-creating master diskettes. UPDATE
-3.2 converts a slave into a master
-and allows the HELLO file to be
-renamed.
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 DOS 3.2.1 - 31 July 1979
 
-DOS 3.2.1 was essentially a
-"maintenance release" of DOS 3.2.
-Minor patches were made to RWTS and
-the COPY program to correct a timing
-problem when a dual drive copy was
-done. Additional delays were added
-following a switch between drives.
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+DOS 3.2.1 was essentially a "maintenance release" of DOS 3.2.  Minor patches
+were made to RWTS and the COPY program to correct a timing problem when a dual
+drive copy was done. Additional delays were added following a switch between
+drives.
+
 DOS 3.3 - 25 August 1980
 
-Introduced in mid 1980 as a
-hardware/software upgrade from DOS
-3.2.1, the DOS 3.3 package includes
-new bootstrap and state ROM chips for
-the disk controller card which
-provide the capability to
-format, read, and write a
-diskette with 16 sectors.
-(These ROMs are the
-same ones used with the LANGUAGE
-SYSTEM.)
-This improvement
-represents almost a 25% increase in
-available disk space over the old
-13 sector format.
-Also included in the 3.3
-package is an updated version of the
-DOS manual, a BASICS diskette (for 13
-sector boots), and a master diskette.
-Although the RWTS portion of DOS was
-almost totally rewritten, the rest of
-DOS was not reassembled and only
-received a few patches:
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+Introduced in mid 1980 as a hardware/software upgrade from DOS 3.2.1, the DOS
+3.3 package includes new bootstrap and state ROM chips for the disk controller
+card which provide the capability to format, read, and write a diskette with 16
+sectors.  (These ROMs are the same ones used with the LANGUAGE SYSTEM.) This
+improvement represents almost a 25% increase in available disk space over the
+old 13 sector format.  Also included in the 3.3 package is an updated version of
+the DOS manual, a BASICS diskette (for 13 sector boots), and a master diskette.
+Although the RWTS portion of DOS was almost totally rewritten, the rest of DOS
+was not reassembled and only received a few patches:
 
-- The initial DOS bootstrap loader
-was moved to $800 under 3.3. It was
-at $300 under 3.2. In addition, as
-stored on the diskette (track 0
-sector 0) it is nibbilized in the
-same way as all other sectors under
-3.3.
+- The initial DOS bootstrap loader was moved to $800 under 3.3. It was at $300
+  under 3.2. In addition, as stored on the diskette (track 0 sector 0) it is
+  nibbilized in the same way as all other sectors under 3.3.
 
-- A bug in APPEND which caused it to
-position improperly if the file was a
-multiple of 256 bytes long was fixed
-under 3.3.
+- A bug in APPEND which caused it to position improperly if the file was a
+  multiple of 256 bytes long was fixed under 3.3.
 
-- A VERIFY command is internally
-executed after every SAVE or BSAVE
-under 3.3.
+- A VERIFY command is internally executed after every SAVE or BSAVE under 3.3.
 
-- All 4 bytes are used in the Volume
-Table Of Contents (VTOC) free sector bit map when
-keeping track of free sectors.  This
-allows DOS to handle up to 32 sectors
-per track. Of course, RWTS will only
-handle 16 sectors due to hardware
+- All 4 bytes are used in the Volume Table Of Contents (VTOC) free sector bit
+  map when keeping track of free sectors.  This allows DOS to handle up to 32
+  sectors per track. Of course, RWTS will only handle 16 sectors due to hardware
   limitations.
 
-- If a LANGUAGE CARD is present, DOS
-stores a zero on it at $E000 during
-bootstrap to force the HELLO program
-on the master diskette to reload
-BASIC.
+- If a LANGUAGE CARD is present, DOS stores a zero on it at $E000 during
+  bootstrap to force the HELLO program on the master diskette to reload BASIC.
 
-- DOS is read into memory from the
-top down (backwards) under 3.3 rather than the
-bottom up. Its image is
-still stored in the same order on the
-diskette (tracks 0, 1, and 2),
-however.
+- DOS is read into memory from the top down (backwards) under 3.3 rather than
+  the bottom up. Its image is still stored in the same order on the diskette
+  (tracks 0, 1, and 2), however.
 
-- Additional programs added to the
-master diskette under 3.3 include
-FID, a generalized file utility which
-allows individual files or groups of
-files to be copied, MUFFIN, a
-conversion copy routine to allow 3.2
-files to be moved to 16 sector 3.3
-diskettes, BOOT 13, a program which
-will boot a 13 sector diskette,
-and a new COPY program
-which will also support single drive
-copies.
+- Additional programs added to the master diskette under 3.3 include FID, a
+  generalized file utility which allows individual files or groups of files to
+  be copied, MUFFIN, a conversion copy routine to allow 3.2 files to be moved to
+  16 sector 3.3 diskettes, BOOT 13, a program which will boot a 13 sector
+  diskette, and a new COPY program which will also support single drive copies.
+
+- Under 3.2, speed differences in some drives prevented their use together with
+  the DOS COPY program.  Because the COPY program was rewritten under 3.3, that
+  restriction no longer applies.
 
-- Under 3.2, speed differences in
-some drives prevented their use
-together with the DOS COPY program.
-Because the COPY program was rewritten
-under 3.3, that restriction no longer
-applies.
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 .nx ch3.1