IBM PERSONAL COMPUTER DOS VERSION 2
AND IBM PERSONAL COMPUTER BASIC LANGUAGE
EXTENSIONS VERSION 2 ARE NOW AVAILABLE
Disk Operating System (DOS) Version 2 and BASIC
Language Extension Version 2 for operation with the IBM
Personal Computer and the IBM Personal Computer XT are
announced and available.
DOS Version 2
This version offers function not available in
previous versions (1 and 1.1) with a higher user memory
requirement. DOS 2 is approximately 12KB larger than DOS 1.1.
When standard (documented) programming protocols have been
observed, most DOS 1 and 1.1 programs should run under Version
2 without change. Examples of nonstandard protocols are: access
of absolute memory locations where DOS resides, and direct
calls to the BIOS. Since DOS 2 uses more memory, some programs
may no longer be able to fit in the same size machines. The
program will still require the same amount of user memory but,
with DOS 2 taking more memory, the amount remaining for the
program will be less. In these cases, a program may have to be
divided into smaller segments or more memory may be added to
Supports one or more 5 1/4-inch diskette drives, or
one or two fixed disks:
. Formatted capacity increased
- 180KB for single-sided diskettes
- 360KB for dual-sided diskettes
. Fixed Disk Initialization program for fixed disk support
. DOS can be started from diskette or fixed disk
. File space allocated dynamically as data is added
. Backup/restore commands to support fixed disk
. Tree-structured directories
. Command to display the directory structure
. Commands to create and remove subdirectories
. Sequential and direct access of data files
. File recovery utility
. Current date and time used in directory entries
. Supports "job stream" sequence of programs as batch files
with conditional (IF-THEN-ELSE) logic
. Automatic execution of program or job stream following
. Graphics screen dump to printer
. Global file name characters for file name searches
. Multiple disk I/O memory buffers for improved performance
. Accepts commands entered in upper or lower case
. Copies of DOS can be copied to formatted diskettes or to
. Line Editor, Debug, Disk Format, Disk Check, Diskette
Copy, Diskette Compare programs
. Linker for language compilers
. User-installable device drivers may be added for new
. Optional "verify" after "write"
. Redirected I/O (Example: keyboard input and direct output
to a file)
. Piping (Example: output from program "A" used as input to
. Divert parallel printer output to Asynchronous
Communications Adapter (Example: attach a serial
. Background file print utility permits simultaneous file
printing with other activity
. Extended device error trapping
Technical information: The IBM Personal Computer DOS
resides on the DOS Diskette. A second diskette contains the
Linker and the sample programs. If the DOS Diskette is present
in diskette drive A or if DOS is resident on the fixed disk,
when the system is started or restarted DOS will automatically
be loaded into random access memory. DOS can also be copied to
any formatted diskette or a fixed disk to provide the same
If automatic program execution is not used each time
DOS is initialized, it will ask the user for the current date
and time. This will be used to identify the most recent update
to a file. If the AUTOEXEC option is used and "unattended"
operation is desired, date and time prompting can be bypassed.
DOS Version 2 uses approximately 24KB of random
access storage. This is an increase over DOS Versions 1 and
1.1. On some systems, this means that additional memory may be
required to permit an application program to be loaded and run.
Prior to running a BASIC language program performing
diskette I/O, one of the two language extensions (Disk BASIC or
Advanced BASIC) must be loaded into memory. (See "the BASIC
Language Extensions" section of this letter.)
Packaging: DOS Version 2 is resident on two
diskettes. They also contain BASIC Interpreter extensions for
Disk BASIC and Advanced BASIC, and sample programs which
demonstrate BASIC and hardware features.
Publications: DOS 2 is described in the IBM Personal
Computer Disk Operating System manual. This manual is required
as a companion to any of the language compiler publications.
Prerequisites: DOS Version 2 requires a minimum of
one diskette drive and 64KB memory, although a minimum of 128KB
is recommended if a fixed disk is installed. Some applications,
because of program requirements, may need more than the minimum
64KB. A diskette may be the original DOS diskette, a copy of
the DOS diskette, or any diskette to which DOS has been
The IBM Personal Computer DOS is a prerequisite for
the BASIC disk and Advanced versions, and provides I/O for the
Macro Assembler, Pascal, FORTRAN, COBOL, and BASIC compilers,
and application programs created by them.
Customer responsibilities: The customer is
responsible for producing a backup copy of the original DOS
diskette, and creating a copy of DOS on other diskettes or
fixed disks as required. All newly purchased diskettes must
first be initialized using the DOS FORMAT utility. Fixed disks
must be initialized with both the FDISK and FORMAT utilities.
Common terms and conditions for both DOS Version 2
and BASIC Extension Version 2 are at the end of this letter.
BASIC language extensions
The IBM Personal Computer BASIC Interpreter is
structured in three functional levels: read-only memory (ROM)
interpreter (cassette), disk, and advanced.
The disk and advanced levels are both resident on the
DOS diskette. Version 2 of BASIC will work only with Version 2
Cassette BASIC not only provides the necessary
cassette input/output instructions, but a high level of support
for display, keyboard, printer, light pen and joysticks, and a
full complement of editing, logic, math, and string functions.
Cassette BASIC is provided with each computer in the form of
built-in ROM, and is operational at the time the system is
first turned on. The cassette port is not supported by the IBM
Personal Computer XT.
Disk BASIC and Advanced BASIC are optional, and may
be loaded into the computer's random access memory from the DOS
diskette or fixed disk. Disk BASIC extensions to the language
provide a full set of instructions, commands, and built-in
function which support the companion Disk Operating System
(DOS), and add date, time-of-day, and communications
Advanced BASIC extensions include the disk functions,
the Graphics Macro Language*, and the Music Macro Language*
(*trademarks of Microsoft, Inc). They enhance display graphics
and support languages, light pens and joysticks, interrupts for
light pens, game controllers, communications, and function
. Superset of function to many microcomputer BASIC
. Disk BASIC is a superset of cassette-level (ROM) BASIC,
and Advanced BASIC is a superset of both.
. Supports new graphics, music, and function key
. Improves programmer productivity by reducing the need for
special machine language subroutines.
. Compatible with IBM Personal Computer DOS.
. Compatible with IBM Personal Computer BASIC compiler.
. High-level communications support for BASIC programmer.
. Current date and time-of-day.
. Double precision transcendental functions (SIN, COS,
. Path name support for tree-structured directories.
. Store and play musical notes (Music Macro Language).
. Advanced graphics: Paint, circle, GET/PUT display
contents, store and draw line segments (drawings),
line styling, tiling, viewports, and windows.
. Advanced light pen and joystick support.
. Event trapping of communications, function key, joystick
or light pen, music, and timer activity.
. Supports up to three printers.
Installation/operation: Either of the two extensions
to BASIC (Disk or Advanced) may be invoked via a simple DOS
keyboard command or loaded automatically with the AUTOEXEC
capability of DOS. Once loaded into the computer's random
access memory, the additional language instructions are
supported, and any BASIC programs written to use disk I/O or
advanced language features will run correctly.
The Disk and Advanced extensions to the BASIC
interpreter reside on the DOS diskette which may be purchased
for any diskette system. Either of the two extension files may
be called as a DOS command:
BASIC Language Level DOS Command
All remaining memory (up to a maximum of 64KB) is
directly addressable from a BASIC language program.
Packaging: BASIC Language Extensions reside on the
DOS diskette which also contains the IBM Personal Computer
DOS. They are described in the BASIC reference manual which is
packaged with each computer. The extensions are DOS
diskette-resident as files named BASIC and BASICA.
Publications: The IBM Personal Computer BASIC
Reference Manual is provided with the system unit and describes
all three levels of BASIC.
Prerequisites: The BASIC Language Extensions require
an IBM Personal Computer with a minimum 48KB memory and at
least one diskette drive. For most applications, however, 64KB
or 96KB will be required. Since the BASIC Interpreter (all
three levels) does not address more than a 64KB working space,
more than 96KB of user memory is normally not used. Personal
Computer DOS is a prerequisite for either the Disk or Advanced
extensions, and is also resident on the DOS diskette. While DOS
can only be loaded from Drive A or a fixed disk, BASIC
extensions may be loaded from any diskette drive or fixed disk.
Since, like DOS, the memory used by the BASIC
extensions is not available for programs or data, consideration
should be given to the minimum memory configuration required.
For total system memory sizes of:
Cumulative 32KB 48KB 64KB 128KB
Memory The approximate remaining user
Used memory is:
(ROM) 4KB 28KB 44KB 60KB 124KB
DOS 2 24KB 8KB 24KB 40KB 104KB
Option 39KB N/A 9KB 25KB 89KB
w/default Comm. 41KB N/A 7KB 23KB 87KB
Option 49KB N/A N/A 15KB 79KB
w/default Comm. 51KB N/A N/A 13KB 77KB
Note: The above are estimates only, provided for guidance.
Customer responsibilities: The customer is
responsible for producing a backup copy of the original DOS
diskette. The customer is also responsible for creating any
AUTOEXEC file that might be desired to cause the automatic
loading of language extensions at each power-on. Disk or
Advanced BASIC extensions may be copied over to program
diskettes for the convenience of the user.
Common terms and conditions
Data security: The customer is responsible for the
protection of data from unintended modification, destruction,
or disclosure, and for the accuracy and integrity of the
Technical assistance: The IBM Personal Computer
Assistance Center (Boca Raton) will provide telephone
assistance to IBM customers who have signed a volume
procurement agreement. The customer will designate a
coordinator who may call the Personal Computer Assistance
Center. Assistance for this coordinator will be available
during the VPA period.
Customers purchasing quantities of less than 20
should contact their IBM marketing representatives who will
provide a local branch office contact who will respond to
Educational allowance: See Notice to IBM Customers,
IBM Personal Computer volume discount schedules and educational
allowance improved," dated March 8, 1983.
Warranty: IBM Program License Agreement provisions
The IBM Personal Computer Program License Agreement:
A copy is packaged and shipped with each program and is visible
to the customer before the diskette package is opened. The
customer is advised that opening the diskette package indicates
acceptance of these terms and conditions. No signature is
The IBM Personal Computer Licensed Program Volume
Licensing Agreement (VLA): See the Notice to IBM Customers
entitled IBM Personal Computer volume discount schedules and
educational allowance improved, March 8, 1983.
DOS/BASIC 2 (6024061) $60
For more information, see your IBM marketing
representative or call the National Marketing Center at the
following toll-free numbers:
In the continental United States
(but outside New York State) (800) 431-2670
New York State (800) 942-1918
Alaska, Hawaii, and Puerto Rico
(call collect) (914) 696-6840
Write to the IBM Corporation, National Marketing Center,
Department 86R, 1133 Westchester Avenue, White Plains, New York