Beneath Apple DOS OCR.pdf - ASCII Express

175 Pages·2011·21.21 MB·English

.ADPIE DOS
(cid:0) (cid:0) (cid:0) (cid:0) (cid:0) (cid:0) (cid:0) (cid:0) (cid:0) (cid:0)
and Pieler Lechner (cid:0) (cid:0) SOFTWJlRE
Fourth Printing. May t982
By Don Worth and Pieter Lechner
A product of
xi
aUJlUTY SOFTWJlRE
6660 Reseda Blvd., Suile 105 'L 1
1 I '1
Reseda, CA 91335
I .N ..
Fachhochschulbibliofhek Niederrheio
Abt. Mond ng!odbach
DISCLAIMER
Qualily Sollware shall haye no liability or re5ponslbilily \0 Ihe
r
, purchaser or any olher person or entity Wilh respect to any liabili'y,
loss or damage caused or alleged to be caused directly or indireclly
I by Ihis manual or lis use, Including bot not hmlled to any Interru!>"
,
lion in service, loss 01 business and anticipatory protils or
consequenllal damages rHulling Irom lhe use 01 this product.
I
• COPYRIGHT <>1981 BY QUALITY SOFTWARE
I
This manual is published and copyrighted by Quality Sollware.
All rights are reserved by Quality Sollware. COPYing, duplicating.
seiling or otherwise distribUling this producl IS hereby expressly
lOfbklden except by prior wnllen consent 01 Quality Sollwar• .
The word APPLE and the Apple logo are regIstered trademarkS
01 APPLE COMPUTER, INC.
APPLE COMPUTER, INC. was not in any way Involved In the
Willing or Olner preparation 01 this manual, nor were the lacls
j)fetented here reviewed lor accuracy by that company. Use oltha
hum APPLE shOuld not be construed 10 represen' any endor .....
mt)(It, olll(lal Of" otherwise, by APPLE COMPUTER. INC.
TABLE OF CONTENTS
INTRODUCTION
Chapter 1
THE EVOLUTION OF DOS
Chapter 2
0053
OOS 31
OOS 3.2
DOS 3.2 1
DOS 3.3
DISKETTE FORMATTING
Chapter 3
TRACKS ANO SECTORS
TRACK FORMATTING
DATA FIELD ENCODING
SECTOA INTERLEAVING
DISKETTE ORGANIZATION
Chapter 4
OISKETTE SPAce ALLOCATION
THE VToe
Us
THE CATALOG 0
J\
THE TRACK/SECTOR LIST
TEXT FilES
BINARY FILES
APPlESOFT AND INTEGEA FILES
OTHER FILE TYPES
EMERGENCY REPAIRS
Chapter 5 THE STRUCTURE OF DOS
OOS MEMORY USE
THE OOS VECTORS IN PAGE 3
WHAT HAPPENS DURING BOOTING
Ch.p'''.
USING DOS FROM ASSEMBLY LANGUAGE
OlReCT USE OF THE DISK DRIVE
CALLING AEAOIWRITE TRACK/SECTOR IAWTS)
AWTS lOB BY CALL TYPE
CALLING THE OOS FILE MANAGER
FilE MANAGER PARAMETEA LIST BY CALL TYPE
THE FILE MANAGER WORK AREA
COMMON ALGOAITHMS
TABLE OF CONTENTS
ChOp'O,7 CUSTOMIZING DOS
SLAVE VS. MASTER PATCHING
AVOIOING RELOAD OF LANGUAGE CARO
INSERTING A PROGRAM BETWEEN OOS AND ITS BUFFERS
8AUN OR EXEC A HELLO FILE
REMOVING THE PAUSE DURING A LONG CATALOG
Chop"'S DOS PROGRAM LOGIC
CONTROLLER CARD ROM - BOOT 0
FIRST RAM BOOTSTRAP LOADER - BOOT 1
OOS 3.3 MAIN ROUTINES
OOS FILE MANAGER
REAOIWRITE TAACK/seCTOR
OOS ZERO PAGE USE
Append'. A EXAMPLE PROGRAMS
TRACK DUMP PROGRAM
DISK UPDATE PROGRAM
REFORMAT A SINGLE TRACK PROGRAM
FINO TAACK/SECTOR liSTS PROGRAM
BINARY TO TEXT FILE CONVERT PROGRAM
Append' •• DISK PROTECTION SCHEMES
Append'. C GLOSSARY
Indell
ACKNOWLEDGEMENTS
Th,nks go to ViC Tolomei IOf his ,",Slance in di'Me,lng D05 3 I.oct to lou Rlyas'Of hili
pllient proofreading Thlnkl liso 10 my wlle Carley lor pulling up wilh the cllICkely clack 01
my Diablo long Into the nlghl.
Don 0 Wor1h
TNinks to !he people It Computer'and 01 Sooth Bay (CAlhlornl') wM lent me syppot'l
bOth ollheirlime and equIpment. arid speci.1 th.nk,loJohn 00111.1$0. whoseencour.gement
helped me to complete Ihe 'ask
BAG OF TRICkS
.3. ...
A Supet' DI" UtNlty by the Authors oj 8_.th (cid:0) (cid:0) (cid:0)OOS
1/ you linG BENEATH APPlE OOS 1.1"'1.11, you iIoI'IOuIO allo find BAG OF TRICKS an Impo,,.nl
help In ...m lnlng .nd (cid:0) (cid:0) (cid:0) (cid:0) (cid:0) (cid:0) (cid:0) (cid:0)up ";'OUr di. ..." ".
BAG OF TRICKS I, I package ollouf mlehlno (cid:0) (cid:0) (cid:0) (cid:0) (cid:0) (cid:0) (cid:0) (cid:0).",brO\lllntt wh!eh go I., beyond thl
....m pte prOOf.tnt In AppendiI A 01 tl'ris tIOOII. Ute< frleOOly and _II aocurMntld. (cid:0) (cid:0) (cid:0) (cid:0)dl'k
(cid:0)(cid:0) (cid:0)(cid:0)(cid:0)(cid:0)(cid:0)(cid:0) (cid:0)'-undoubtedly the besl one ,w"Jlble'or m. Apple II, (cid:0) (cid:0) (cid:0) (cid:0) (cid:0) (cid:0) (cid:0)" !he low prIc.
(cid:0) (cid:0) (cid:0) (cid:0) (cid:0) (cid:0)
The 1000f prog,.ml and thel, lunelions .ra:
I TRAX durnjM .nd ..." ". .... "'11' !tICk. -'1!let t l-MeIOf Of .8-Mc:IOf. dltpllp tne Inter".!
Apple d,p.". !Otll'lllthng InfOfll'lllllOtl, .....:j ". exception' to , ..n OIIrd formalS
2 ,I!N\eITm .... ,11 ,.IOtIl'lllI one Ot fIlOI" tr.cU on dl ....n ., ... hile Inempling to Pf_ Iny atl on
Both 13-MeIOt Ind l6-MelOt IOtm,1S 1'1 Iuppoflld Mo,.
3. ZAP pro¥idn IhtI buIc capabihly to f'IIId. (cid:0) (cid:0) (cid:0)(cid:0)Ind uPCIIII di,kln. MeIOfi thin
50 eomtnllldt _ IVI,lebie 10 ...." IIIe u_ In Ioc:Iting. COInpII"ng, Ind chlngitlg tnedl"
Of! the d,1io;1'I11 Prinler IUppofl. 100. You won'I "-lieve now mlny UMlul OPIioM ZAP ha,
.. flllCAT lutomttMth, P'o(;M,ol 'eeo. ... 'ng.d.mIlgldClI.logtrlC. TII.ditloetl.etnOfo
(cid:0) (cid:0) (cid:0) (cid:0) (cid:0) (cid:0) (cid:0)lOt trac. HCtor h. ... theEnn ,",,,.. UHf can .uIgn.".me to """ound Irf flllCA
and '"lOtI IhenIIO the CI"1og ClI. .. mIIy be , ..t OtId In tllll ... ..,..
II you hive _ "-d • ditlo c,ull, you know ... h.\. good dilk (cid:0) (cid:0)(cid:0)(cid:0)(cid:0)(cid:0)(cid:0)II wortll. e.gln,.,.,. ... ,11
.pprecilot. tile "hind-hOldIng" IUIOtIaII Ihll ... 11I.u,.1 him In repairing hll CllmII!JId di. ..." H •
.....:j trtl ."panenc.ct .......... 11 .ppreelol'- now lut (cid:0) (cid:0) INtily ne can perIorm .f'I.Ilpll and
r.palfl
BAG Of TAICI<S ,eq ... J'M I .81< Apple II Ot Appl. \I Plu •.
1
CHAPTER
INTRODUCTION
i)cne!'th Apple OOS is intended to serve as a companion to
A.pple's DOS Manual, providing additional information for the
advanced programmer or the novice Apple user who wants to
know more about the structure of diskettes. It is not the
Intent of this manual to replace the documentation provided
bV Apple COlllputer Inc. Although, for the sake of
continuity. some of the material covered in the Apple manual
I. also covered here, it will be assumed that the reader is
re.aonably familiar with the contents of the DOS Manual.
Since all chapters presented here may not be of use to each
Apple owner, each has been written to stand on its own.
The information presented here is a result of intensive
disassembly and annotation of various versions of DOS by the
authors and by other experienced systems programmers. It
also draws from application notes , articles, and discussions
with knowledgeable people. This manual was not prepared
with the assistance of Apple Computer Inc. Although no
guarantee can be made concerning the accuracy of the
Information presented here, all of the material included in
o neath Apple DOS has been thoroughly researched and
tested.
There were several reasons for writing Beneath Apple DOS:
TO show direct assembly language access to DOS.
To help you to fix clobbered diskettes.
TO correct crrors and omissions in the Apple documentation.
TO allow you to customize DOS to fit your needs.
TO provide complete information on diskette formatting .
I NI., WUE SEVEMl fIfAS(ljS (cid:0) (cid:0)(cid:0) (cid:0) (cid:0) (cid:0) (cid:0) (cid:0) "BENEATH API'lE (cid:0) (cid:0) (cid:0) (cid:0) (cid:0) .(cid:0)...
,-,
When Apple Computer Inc. introduced its Disk Operating
System (DOS) version 3 in 1978 to support the new DISK II
drive, very little documentation was provided. Later, when
DOS 3.2 was released, a 178 page instructional and reference
manual became available covering the use of DOS from BASIC
in depth and even touched upon some of the internal working'
of DOS. With the advent of DOS 3.3, the old 3.2 manual waa
updated but the body of information in it remained
essentially intact. Beyond these Apple manuala, there have
been no significant additions to the documentation on DOS,
apart from a few articles in APPLE user group magazines and
newsletters. This manual takes up where the Disk Operating
System Manual leaves off .
Throughout this manual, discussion centers primarily on DOS
version 3.3. The reasons for this are that 3.3 was the most
recent release of DOS at the time of this writing and that
it differs less from DOS 3.2 than one would imagine.
Wherever there is a major difference belween the various DOS
releases in a given topic, each release •• 11 be covered.
In addition to the DOS dependent information provided, many
of the discussions also apply to other operating systems on
the Apple II and Apple III . For example, disk formatting at
the track and sector level is, for the most part, the same.
14
2
CHAPTER
THE EVOLUTION OF DOS
Since its introduction, Apple OOS has gone through three
major versions. All of these versions look very much the
same on the surface. All commands supported by 005 3.3 are
a180 supported in 3.2 and 3,1. The need for additional
versions has been more to fix errors in DOS and to make
.tnor 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.
DOS 3 • 2t June 1978
I DOS 3.1 - 20 July 1978
,
The first release of DOS was apparently a victim of a rush
1 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 Febru.ry 1979
Although OOS 3.2 embodied more changes from its predecessor
than any other release of OOS, 9o, of the basic structure of
OOS 3.1 was retained. The major differences between DOS 3.1
and 3.2 and later versions of OOS 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.
- Input prompts (>,1,*) are echoed when MON 0 is in effect,
not under MON I as was the case under 3.1.
- When a DOS command was entered from the keyboard, OOS
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, 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.
,-,
- Some OOS co. .a nds are allowed to create a new file, other.
will not. Under OOS 3.1, any reference to a file that
didn't exist, caused it to be created. This forced OOS 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 IDOnitor required that the
MOnitor status register location ($48) be set to zero
before reentering OOS. Under DOS 3.2 this is no longer
nece •• ary.
- The Read/Write-Track/Sector (RWTS) section of DOS disable.
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 8 (byte offset) keyword ts 0 under
3.2.
- DOS was reassembled for 3.2 causing most of it.
interesting locations and routines to move slightly. This
played havoc with user programs and utilities which had
DOS addressea built into them.
- Additional file types (beyond T, I, A, and B) are defined
within DOS J.2, although no commands yet support the • . Th.
new types are S, R, a new A, and a new B. R has
aubsequently been used by the DOS TOOLKIT for relocatable
object .odule assembler files . At present, no other uae
ia aade of these extra file types.
- Support was added under 3.2 for the AUTOSTART ROM.
- All tilea open when a diak full condition occurs are
closed by DOS 3.2.
- As with each new release of DOS, several new programs were
added to the I114ster diskette for 3.2. Among these was
UPDATE 3.2, a replacement for MASTER CREATE, the utility
for creating master diskettea. UPDATE 3.2 converta a alave
into a ..a ter and allowa the HELLO file to be renamed.
001 3.2.1 • 31 July 1171
OOS 3.2.1 vas essentially a -maintenance cele• •• - of DOS
3.2. Minoc patches were ..d e to RWTS and the COPY progr ••
to correct a timing problem when a dual drive copy was don ••
Additional delaya vere added folloving a switch between
drivea.
2-2
DOS 3.3 - 25 AugUll1t1C1
Introduced in mid 1980 as a hardware/software upqrade from
OOS ).2.1, the OOS 3.) package includes new bootstrap and
.tate ROM chips for the disk controller card which provide
the capability to format, read, and write a diskette with 16
'ectors. (These ROMs are the same ones used with the
I.ANCUAGE SYSTEM.) This improvement represents almost a 25'
Inc rease in available disk space over the old 13 sector
rorMat. Also included in the ).) package is an updated
version of the OOS manual, a BASICS diskette (for 13 sector
boots) , and a master diskette. Although the RWTS portion of
OOS was almost totally rewritten, the rest of 005 was not
reassembled and only received a few patches:
- The initial 005 bootstrap loader was moved to $800 under
3.1. It was at $)00 under 3.2. In addition, as stored on
I the diskette (track 0 sector 0) it is nibbilized in the
• . ame way as all other sectors under ).1 .
- A bug in APPEND which caused it to position improperly if
I
the file was a multiple of 256 bytes long was fixed under
• ) .1 .
I - A VERIFY command is internally executed after every SAVE
or BSAVE under 1.1.
- All • bytes are used in the Volume Table Of Contents
(VTOC) free sector bit map when keeping track of free
sectors. This allows 005 to handle up to )2 sectors per
track. Of course, RWTS will only handle 16 sectors due to
hardware limitations.
If a LANGUAGE CARD is present, OOS stores a zero on it at
$EOOO during bootstrap to force the HELLO program on the
master diskette to reload BASIC.
OOS is read into memory from the top down (backwards)
under 3.3 rather than the bottom up. Its image is st ill
stored in the same order on the'diskette (tracks 0, I, and
2) , however.
Additional programs added to the master diskette under 3.3
include FlO, 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 11, 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 BOrne drives prevented
their use together with the OOS COpy program. Because the
COpy program was rewritten under 1.3, that restriction no
longer applies.
2-3