DRAPER PASCAL#
Version 2.1
Copyright 1989 by Norm Draper
For the Atari 400, 800, XL, or XE series computers
ATR-Images:#
- Draper Pascal/drpascal.atr
Draper Pascal - Disk A
- Draper Pascal/drpascb.atr Draper Pascal - Disk B
- Pascal Documentation.atr Pascal Documentation.atr
Description:#
- Draper Pascal 2.1.pdf Draper Pascal 2.1 description
- KYAN PASCAL - A PROGRAMMING LANGUAGE
Table of Contents
- DRAPER PASCAL
- ATR-Images:
- Description:
- Disk Based Documentation
- The Shareware Concept
- Features
- Introduction
- What is Pascal?
- What is Draper Pascal?
- About this manual
- What is Draper Pascal made of?
- About the DOS
- Ramdisk support
- Getting Started
- Main Menu
- Run Program
- Disk Directory
- Compile Program
- Edit a Program
- Exit to DOS
- List a file
- Trace on
- The Editor
Disk Based Documentation#
This document contains the "Getting Started" section plus other sections from the actual Draper Pascal manual. It is designed to get you up and running and doing useful things with Draper Pascal in a very short time. It does not, however, contain a detailed description of all the Draper Pascal definitions or pretend to be a comprehensive tutorial or user's reference. Registered users will receive the actual Draper Pascal manual which does contain a complete description of all definitions plus other information. Details on registering are in the last section titled "Registration Form".
The Shareware Concept#
Draper Pascal is distributed on a Shareware basis. You may use Draper Pascal without charge for the purpose of evaluating it's suitability for your use. If you find that Draper Pascal is worth continuing to use, then you are requested to become a registered user and gain the additional benefits that go along with it. Simply complete the registration form and mail it in to us with the very reasonable payment of only $15.00. When you register your copy of Draper Pascal, you'll receive the latest version of the software if your registered version is not current, along with a comprehensive printed user manual.
If you have received this copy from a Users' Group, "Software Library" or "SIG", and have paid a small fee (usually $3 to $10), you have NOT acquired the registered rights or continued right to use Draper Pascal. This fee was for the convenience of obtaining the diskette with Draper Pascal on it. The fee does NOT apply to the registration fee.
You may freely copy Draper Pascal for distribution under the Shareware concept, without charge.
You may NOT charge any fee for the Draper Pascal program or documentation without our written approval.
You may NOT distribute Draper Pascal or it's documentation in connection with ANY commercial venture, product, publication or service unless you obtain the royalty-free license by registering.
Features#
- Draper Pascal is a complete package allowing the user to create, compile, and execute programs written in the Pascal language.
- Many features from both UCSD and ISO standard Pascals plus many extensions, such as sound and graphics, to make use of the versatile Atari hardware.
- Pascal structured programming features, including IF-THEN-ELSE, WHILE-DO, CASE-OF-ELSE, FOR-TO/DOWNTO-DO, and REPEAT-UNTIL are included.
- FUNCTIONs and PROCEDUREs using local or global variables. Integer type variables can be passed directly.
- Data types supported include: Character, String, Integer, Real, Boolean, Record, and File. One and two dimension arrays are also supported for all data types other than File and Record.
- Only one disk drive and 48K RAM are required. Multiple, and double density, disk drives are supported.
- Machine language subroutines may be loaded and called.
- Program chaining is supported.
- No limit on source program size. "Include" files are supported.
- One-pass compiler generates pseudo code directly.
- Maximum program pseudo code size is about 30K bytes.
- Textual compiler error messages.
- Execution debugging features include instruction trace and stack display.
- Special options for error display and break key disable.
- Single keystroke program execution repeat, exit to DOS, or exit to Main Menu program are featured.
- Includes Editor program to create, modify, and print Pascal source files, or other text type files.
- Includes Main Menu program (Pascal source included) for easy select of Compiler, Editor, or utility functions, such as directory or file listing. Main Menu program may be replaced with a user written program to create a turnkey operation.
- Ramdisk support. Details provided to registered users.
- Works with most popular versions of DOS.
- Easy to use. No linking required. Compile and execute immediately.
- Royalty free license available to registered users.
- Includes sample programs.
- Comprehensive user manual provided to registered users. Complete examples and BASIC equivalents given for each reserved word.
Introduction#
Draper Software welcomes you to the world of Pascal for the Atari 400/800, XL, and XE series Computer systems.
What is Pascal?#
Pascal is a high-level structured programming language developed by Niklaus Wirth in 1971. It is easy to understand and well suited for program development and maintenance.
What is Draper Pascal?#
Draper Pascal is not a "standard" Pascal. It has a number of commands which are exactly like ISO and UCSD versions, some which are similar, and many "extensions" which bring out the true power of the Atari computer in an easy to use manner. It was designed to require only one disk drive for operation, but not be limited to only one. At this time, it has been shown to work with all hardware and software configurations where enough memory is provided. This implementation also has a number of commands which are familiar to Atari BASIC users, such as POKE, PEEK, SETCOLOR, NOTE, POINT, etc..
About this manual#
This manual is intended to familiarize you with all the features of Draper Pascal. It is not intended to teach you how to program in Pascal. However, if you already know Atari BASIC, then you can understand the Pascal statements more easily by referring to their BASIC equivalents shown after the definition of each Pascal reserved word in the complete manual provided to registered users. It is recommended that you read this manual completely to be familiarized with its features and restrictions.
What is Draper Pascal made of?#
This implementation of Pascal is made up of three main components. They are the Supervisor (sometimes referred to as runtime routines), the Compiler, and the Editor. The Supervisor is a high performance machine language program which simulates a 16-bit pseudo computer. The Compiler translates Pascal source code into pseudo-code instructions to be executed by the Supervisor. The Editor is used to enter and modify Pascal source programs. It may also be used to edit data files, or BASIC programs which have been LISTed to a disk or tape. These components are explained in detail within this manual.
For a description of the various files included on the supplied diskette, refer to the 'System Information' section.
About the DOS#
Draper Pascal can be used with most popular Disk Operating Systems. It has been tested with Atari DOS 2.5, SpartaDOS 3.2d, and MYDOS. You should format a diskette with DOS on it to contain the Draper Pascal system. Since the Draper Pascal Supervisor is named AUTORUN.SYS, it will execute immediately after the disk is booted. For XL and XE computers, you do not need to hold down the Option key while booting unless you are using SpartaDOS. If using SpartaDOS, you may want to rename AUTORUN.SYS to PASCAL.COM and create a STARTUP.BAT file containing the following two lines:
BASIC OFF PASCALThis documentation file is not required to be on that same diskette.
Ramdisk support#
Draper Pascal supports the use of the "Ramdisk" capability provided by using a DOS that supports a ramdisk like Atari DOS 2.5 or SpartaDOS 3.x with an Atari computer system having sufficient memory to support the ramdisk. While using this feature, the Editor takes less than two seconds to load and the Compiler takes less than three seconds. Details on setup and use of this feature are provided in the complete manual provided to registered users.
Getting Started#
This section is intended to show by example how to use the Draper Pascal system. You will edit, compile, and run a sample program. Information displayed by the computer is shown in normal type while responses to be entered by you are shown underlined with dashes (---). To begin with, make sure you have 48K RAM installed and no cartridge in place. Boot the disk now by placing it in disk drive 1 and turning on the power to the Atari computer. After the Supervisor has finished loading, you will see a screen that looks like this:
DRAPER PASCAL 1 - Run Program 2 - Disk Directory 3 - Compile Program 4 - Edit a Program 5 - Exit to DOS 6 - List a file 7 - Trace on
DRAPER SOFTWARE
EDITOR
A - Add line(s) at end
C - Change line(s)
D - Delete line(s)
E - Edit a line
F - Filer menu
I - Insert before line
L - List line(s)
M - Menu
P - Print line(s)
Q - Quit
S - Scan line(s)
X - Exit to Compiler
A,C,D,E,F,I,L,M,P,Q,S,X,?->F Select Filer menu
-
A - Append file
D - Directory list
L - Load file
S - Save file
L Load a file
-
Enter filename -> SAMPLE1 Enter the name of the file
------- to be loaded. The name of
the last file edited,
compiled, or run will be
filled in by the Editor.
You may have to overtype
it with the name shown.
A,C,D,E,F,I,L,M,P,Q,S,X,?->L List the file on the
- screen
Line from -> Just press RETURN for
- 'Line from' and 'Line to'.
Line to -> This will give a list of
- the entire program in
memory.
1:PROGRAM KALEIDOSCOPE;
2:VAR I,J,K,W,X:INTEGER;
3:BEGIN
4: MAXGRAPH(19);
5: GRAPHICS(19);
6: X:=0;
7: REPEAT
8: FOR W:=3 TO 50 DO
9: BEGIN
10: FOR I:=1 TO 10 DO
11: BEGIN
12: FOR J:=0 TO 10 DO
13: BEGIN
14: K:=I+J;
15: COLOR(J*3/(I+3)+I*W/12);
16: PLOT(I+8,K);
17: PLOT(K+8,I);
18: PLOT(32-I,24-K);
19: PLOT(32-K,24-I);
20: PLOT(K+8,24-I);
21: PLOT(32-I,K);
22: PLOT(I+8,24-K);
23: PLOT(32-K,I)
24: END
25: END
26: END
27: UNTIL X=99 (* UNENDING LOOP *)
28:END.
A,C,D,E,F,I,L,M,P,Q,S,X,?->I Let's insert a comment
- before line 15.
Line -> 15
--
15: (* MY FIRST EDIT *) Enter the data to be
------------------- inserted when prompted for
16: line 15. Just press RETURN
- when prompted for line 16.
This will terminate insert
mode.
A,C,D,E,F,I,L,M,P,Q,S,X,?->L List again to verify that
- the change was made
correctly.
Line from ->
-
Line to ->
-
1:PROGRAM KALEIDOSCOPE;
2:VAR I,J,K,W,X:INTEGER;
3:BEGIN
4: MAXGRAPH(19);
5: GRAPHICS(19);
6: X:=0;
7: REPEAT
8: FOR W:=3 TO 50 DO
9: BEGIN
10: FOR I:=1 TO 10 DO
11: BEGIN
12: FOR J:=0 TO 10 DO
13: BEGIN
14: K:=I+J;
15: (* MY FIRST EDIT *)
16: COLOR(J*3/(I+3)+I*W/12);
17: PLOT(I+8,K);
18: PLOT(K+8,I);
19: PLOT(32-I,24-K);
20: PLOT(32-K,24-I);
21: PLOT(K+8,24-I);
22: PLOT(32-I,K);
23: PLOT(I+8,24-K);
24: PLOT(32-K,I)
25: END
26: END
27: END
28: UNTIL X=99 (* UNENDING LOOP *)
29:END.
A,C,D,E,F,I,L,M,P,Q,S,X,?->F Let's save the program
- back to disk drive 1
under the same name.
A - Append file
D - Directory list
L - Load file
S - Save file
S
-
Enter filename -> SAMPLE1
-------
A,C,D,E,F,I,L,M,P,Q,S,X,?->X Now let's exit directly to
- the Compiler.
Draper Software
Pascal Compiler
Version 2.1
Copyright 1989
by Norm Draper
Enter Filename:
SAMPLE1 Enter name of program to
------- be compiled. The name of
the last program edited,
compiled, or run will be
filled in by the
Compiler.
Enter List Output Filespec
Default is E: Just press RETURN at this
- point to have the compile
list directed to the
screen.
0000 PROGRAM KALEIDOSCOPE;
0000 VAR I,J,K,W,X:INTEGER;
0003 BEGIN
0003 MAXGRAPH(19);
0017 GRAPHICS(19);
001B X:=0;
001E REPEAT
0022 FOR W:=3 TO 50 DO
002A BEGIN
0035 FOR I:=1 TO 10 DO
003D BEGIN
0048 FOR J:=0 TO 10 DO
004F BEGIN
005A K:=I+J;
0062 COLOR(J*3/(I+3)+I*W/12);
008A PLOT(I+8,K);
0098 PLOT(K+8,I);
00A6 PLOT(32-I,24-K);
00B8 PLOT(32-K,24-I);
00CA PLOT(K+8,24-I);
00DC PLOT(32-I,K);
00EA PLOT(I+8,24-K);
00FC PLOT(32-K,I)
010A END
010A END
010C END
011C UNTIL X=99 (* UNENDING LOOP *)
0142 END.
0147
ADDR NAME
---- --------
0003 I
0004 J
0005 K
0006 W
0007 X
5 Compiler table entries used
*** Program Execution Completed *** Press the SELECT key at
Highest Stack Address Used = $AFF8 this point to take us to
<START>Repeat,<SELECT>Menu,<ESC>Exit the main menu.
DRAPER PASCAL
VERSION 2.1
1 - Run Program
2 - Disk Directory
3 - Compile Program
4 - Edit a Program
5 - Exit to DOS
6 - List a file
7 - Trace on
Copyright 1989
by Norm Draper
1 Select '1' to run the
- program that was just
compiled.
Enter name of program to be run
SAMPLE1 The name of the last
------- program edited, compiled,
or run will be filled in
by the main menu program.
Overtype the name if you
want to run a different
program.
At this point you should have a nice kaleidoscope pattern being displayed on your television screen. To stop it, press the BREAK key. To repeat execution, press the START key. To return to the main menu, press the SELECT key. To exit to DOS, press the ESC key.
Another program, SAMPLE2, is also provided for you to practice with. It will display Roman numerals for powers of two between 1 and 4096. Compile it, turn on the trace via the main menu, and run it. After it is finished, press CTRL-T to display the trace table, and CTRL-S to display the stack contents. When prompted for 'Where? Filespec', enter 'E:'. For a description of the stack display line, refer to the 'DUMPSTK' command in the 'Pascal Definitions' section of the manual provided to registered users.
Main Menu#
The Main Menu is the initial program to be run by the Supervisor. It is written in Pascal. The source code is provided for it and you may customize it as you see fit. The disk filename for the source is 'INIT.PAS'. The pseudo code program that is initially executed is 'INIT.PCD'. It would be wise to copy 'INIT.PCD' to another name to be used in case your compile of the menu program is not successful. Or, you could rename INIT.PAS to something else, like NEWINIT.PAS, and compile it to produce NEWINIT.PCD. Then you can use the 'run' option (mentioned below) to test your modified program.
The Main Menu appears as follows:
DRAPER PASCAL
VERSION 2.1
1 - Run Program
2 - Disk Directory
3 - Compile Program
4 - Edit a Program
5 - Exit to DOS
6 - List a file
7 - Trace on
Copyright 1989
by Norm Draper
Each of the menu options will now be explained:
Run Program#
Use this option to execute a program that has previously been successfully compiled. You will see the following prompt:
Enter name of program to be run
The Main Menu program will fill in the name of the last program
edited, compiled, or run. If this is the one you want, all you
have to do is press RETURN. If it is not the one you want, just
overtype the name shown with the one you want.
Disk Directory#
This option will provide you with a list of all, or selected, files on one of your disk drives. You will receive the prompt 'Filespec?'. If you just press RETURN at this point, you will see a list of all files on the default drive. If you enter 'D2:', you will see all files on drive 2. To show only selected files, use wildcards in the normal manner. For example, enter 'D1:INIT.*' to show only files named INIT with any suffix from drive one. At the end of the list, you will be prompted to press any key to continue. After pressing any key, the Main Menu will be re-displayed.
Compile Program#
This option sends you directly to the Pascal compiler. You will be prompted for the name of the program to be compiled, after the Compiler is loaded. If you have already edited, compiled, or run a program, the name will be shown and may be used by just pressing the RETURN key. For more information, refer to the section of this manual on 'The Compiler'.
Edit a Program#
Control is transfered to the Draper Pascal Editor when this option is chosen. For more information, refer to the section of this manual on 'The Editor'.
Exit to DOS#
Pascal execution is terminated by this option. Control is passed to the Disk Operating System.
List a file#
This convenience entry is provided to allow you to view, on the screen, any text file on disk or tape. You are prompted to enter the name of the file to be listed. The file is assumed to reside on the default drive if a colon (:) is not found within the name you specify. At the end of the list, you will be prompted to press any key to continue. After pressing a key, the Main Menu will appear again.
Trace on#
The wraparound internal trace may be turned on (or off) with this option. The trace is used only for debugging purposes and may be viewed at program termination time by pressing CTRL-T. Program execution speed is slightly degraded while the trace is active. You will be prompted to enter the number of trace entries to be maintained by the system. Each trace entry requires 10 bytes of storage at the high end of memory. The trace may not be used during graphics displays because screen memory is also at the high end of memory. To turn the trace off and remove the memory allocation of the trace table, enter zero when prompted for the number of entries to maintain. The trace format is described in the manual provided to registered users.
The Editor#
The Editor is used to create, modify, and save Pascal source files. It may also be used to process other text type files, like BASIC programs which have been LISTed to disk or tape. It is a line oriented editor. Combined with some type of formatting program, it may be used for word processing applications. The entire source to be edited must be in memory at one time. If your Pascal program will not fit within the limits of the Editor, then you can use the INCLUDE feature of the Compiler to allow segments of a program to be edited separately. Refer to the section on "THE COMPILER" for more information on the INCLUDE feature. Source code for the Editor is listed in the manual provided to registered users. Some key points to be noted about this editor are as follows:
- Each line is referred to by line number, however, no line numbers are stored either internally or on the disk or tape.
- Each line may contain up to 80 characters. This may be changed by altering the constant called MAXLENGTH and re-compiling the Editor. A source listing of the Editor is provided to registered users.
- A maximum of 250 lines of text may be edited at one time. This may be changed by altering the constant called MAXLINES and re-compiling the Editor. An increase in MAXLINES should correspond with a decrease in MAXLENGTH, and vice versa. A source listing of the Editor is provided to registered users.
- When entering or editing a line, the line must be terminated by pressing the RETURN key.
- As lines are inserted into, or deleted from, the source file, the remaining lines are automatically renumbered.
- A line of source may extend onto more than one screen line.
- Due to operation of the Atari operating system, a blank line may not be directly entered. To enter a blank line, you must first enter a non-blank character (like a period), then use the Editor Change command to change the character to a space.
- Input operations (Append and Insert) are terminated by entering a null line (just pressing the RETURN key).
- The BREAK key is disabled by the Editor to prevent loss of data. It is enabled again at termination of the Editor.
- If you enter or change data then try to Quit or exit to the Compiler without first saving the data onto disk, you will receive an option to either save the data or ignore it and continue.
- Cassette tape files may be loaded, edited, and saved by the Editor. The Compiler does not support tape input, though. You would first have to load the file from tape, with the Editor, then save it to disk.
Wiki-Editing pending
EDITOR COMMANDS
General Prompts
The following prompts are general in nature and are common among
many of the editor commands to be described below.
Line ->
You are prompted to enter one line number, as opposed to a range
of line numbers. It is used by the INSERT Editor command and
refers to the line before which the inserted line(s) will be
placed.
Line from ->
This is the first prompt for a range of line numbers. Enter the
low number of the range. If you just press RETURN, line number 1
is assumed.
Line to ->
Enter the high line number in the range desired. If only one line
is to be acted upon, that number must be entered in both this
prompt and the one mentioned above. If you just press RETURN, the
highest line number in the buffer will be assumed. If the number
you enter is less than the 'Line from' value, the 'Line from'
value will be used here.
18
Draper Pascal 2.1 The Editor
Enter filename ->
This prompt is shown when loading, appending, and saving files.
The last filename used is filled in after the arrow. If this is
the file you wish to use now, then all you have to do is press
RETURN. A full filespec may be entered, but is not required. If a
colon (:) is not found within the filename specified, then the
default drive is assumed. If the filename given does not contain a
period (.), then a suffix of .PAS is assumed.
The Commands
A - Add line(s) at end
This command is used to add lines after the last line currently in
the buffer. If the buffer is currently empty, then line 1 will be
assumed as the starting point. In this manner, you can create a
new file if one has not been loaded. You can append as many lines
as you like. When you are finished entering lines, just press
RETURN without entering any data on the line (null line).
Prompts used: None
C - Change line(s)
The Change command allows you to change one specified string
pattern to another for the first occurance in each line within the
range of lines specified. After being prompted for the line number
range, you are asked for the data to 'Change from ->' and 'Change
to ->'. Enter any string of characters at each prompt. Imbedded
blanks are allowed. If you just press RETURN for the 'Change to'
prompt, the first occurance of the 'Change from' data within each
line will be deleted.
Prompts used: 'Line from', 'Line to', 'Change from', 'Change to'
D - Delete line(s)
This command allows you to delete a line or a range of lines from
the file in memory. The whole file in memory will be deleted if
you just press RETURN when prompted for both 'Line from' and 'Line
to'. Be aware that all lines following the range deleted will be
renumbered, to fill the gap just made. If you desire to delete a
number of line ranges, delete those with the highest numbers first
and proceed toward the beginning of the file. That way, you won't
have to do a LIST after each range delete to find out what the new
line numbers for the following lines are.
Prompts used: 'Line from', 'Line to'
19
Draper Pascal 2.1 The Editor
E - Edit line(s)
The Edit command is used to edit (or make individual changes to) a
line or range of lines that already exist in memory. If a range is
specified, the lines are presented to you one at a time. As each
line is presented, you may use any of the normal Atari editing
keys (like right and left cursor, insert, delete), to alter the
data. Just press RETURN when you are finished with each change. If
you don't want to make a change to a line shown, just press
RETURN.
Prompts used: 'Line from', 'Line to'
F - Filer menu
The Filer is a subsystem which handles communication with an
external device (disk or tape). The features provided are as
follows:
A - Append file
A file is read from disk or tape and added to the end of the
file currently in memory. The data in memory prior to the
append remains unchanged.
Prompts used: 'Enter filename'
D - Directory list
This command is used to provide a directory list of the
different files on a diskette. You are prompted for
'Filespec?'. Enter the disk drive number and selection
criteria for the directory list. If you just press RETURN you
will see a directory list of all files on the default drive.
To see all files on drive two, enter 'D2:' or 'D2:*.*'. To see
only files with a suffix of PAS on drive one, enter
'D1:*.PAS'.
Prompts used: 'Filespec?'
L - Load file
This is the way to load a file into memory from disk or tape.
If any data was currently in memory, it is deleted and
replaced by the file read in.
Prompts used: 'Enter filename'
20
Draper Pascal 2.1 The Editor
S - Save file
Data is copied from memory to disk or tape with this command.
The data currently in memory remains unchanged. You are
prompted for filename and may use whatever name you wish. It
is not necessary to save a file under the same name as was
used to load the file. You should save data to disk frequently
if you are making extensive changes. That way you won't have
to re-do as much if something goes wrong.
Prompts used: 'Enter filename'
I - Insert before line
This command allows you to insert one or more lines at any point
within the file in memory. The inserted data is placed before the
line number you specify. To terminate insert mode, just press
RETURN without entering any data on the same line (null line).
Note that all lines after the point of insertion will
automatically be renumbered.
Prompts used: 'Line ->'
L - List line(s)
One or more lines of data from memory are listed on the screen
with this command. During the list, you may stop the scrolling by
pressing either the space bar or RETURN. To resume scrolling,
press any other key other than ESC. The ESC key may be pressed to
prematurely terminate the listing.
Prompts used: 'Line from', 'Line to'
M - Menu
The main Editor menu is presented in response to this command. A
question mark (?) may also be used to display the main menu.
Prompts used: None
P - Print line(s)
This command is used to create a list of data in memory on a
printer attached to the Atari parallel port (P:). Internal line
numbers are also directed to the printer although they do not
actually exist within the file on disk or tape.
Prompts used: 'Line from', 'Line to'
21
Draper Pascal 2.1 The Editor
Q - Quit
This command is used to exit from the Editor when you are finished
editing your data. Control is given to the Main Menu program. If
you have changed the data in memory and have not saved it prior to
quitting, you will be given the option of saving the data or
ignoring the changes and exiting. If you are going to compile a
Pascal program immediately after quitting the Editor, you may use
the 'X' command described below.
Prompts used: None
S - Scan line(s)'
This command allows you to display all lines within a specified
range which contain a specified character string. The character
string may contain any characters, including imbedded blanks. To
temporarily stop the listing, press either the space bar or
RETURN. To abort the listing, press ESC. Press any other key to
continue as normal.
Prompts used: 'Line from', 'Line to', 'Scan for'
X - Exit to Compiler
This command terminates the Editor and transfers control directly
to the Compiler. If the file in memory has been changed but not
saved prior to the Exit command, you will be prompted to either
save the file or ignore the changes and proceed to the Compiler.
Prompts used: None
22
Draper Pascal 2.1 The Compiler
The Compiler
The Compiler is used to translate words that we humans understand
into "words" that the computer can understand. The computer words
are referred to as pseudo-code, or p-code for short. These
pseudo-code instructions are understood and executed by the
Supervisor.
This is a single pass goal oriented compiler. It expects the
proper syntax for a statement. If correct syntax is not found, the
compilation stops, and an error number with associated text
description is displayed. At this point, you are given the option
of quitting or returning to the Editor to correct the problem and
do the compile again.
The Compiler itself is written in Draper Pascal and occupies about
28K of RAM memory space.
The first prompt from the Compiler is 'Enter filename:'. The name
of the last program edited, run, or compiled is filled in for your
convenience. If this is the one you want, just press RETURN. If it
is not the one you want, just overtype it with the name you
desire. The name you provide will become the new default name for
the Editor, Compiler, and Main Menu 'Run' option. No suffix is
allowed when specifying filename. The Compiler will add the
standard '.PAS' to it for you. If the source does not reside on
the default disk drive, then you must prefix the filename with
'Dn:' where 'n' is the disk drive number where the source resides.
The default disk drive is normally disk drive number one, but is
changed to the Ramdisk drive number if you are taking advantage of
the Ramdisk feature of a Disk Operating System that supports it.
Ramdisk initialization is explained in the manual provided to
registered users.
The next prompt is 'Enter List Output Filespec'. The default (if
you just press RETURN) is the screen (E:). The list output may go
to any normal output device, such as printer (P:) or disk
(D:LISTNAME.PRN).
A number of additional points are mentioned below:
1. Comments are delimited by '(*' on the left end and '*)' on the
right end. Any characters may appear within comments. Comments
may appear anywhere within the program.
2. 'Include' files are supported. You may have procedures,
functions, or any part of a program included in a compile,
even though it is not actually part of the file being
compiled. It is a variation of a comment which allows you to
do this. The format is as follows:
(*$I XXXXXXXX *) or (*$I D1:XXXXXXXX *)
23
Draper Pascal 2.1 The Compiler
The dollar sign and 'I' must be right next to '(*' and must be
followed by one space. Then you may mention the 'D' for disk
and drive number (if other than the default drive is to be
used). Follow it with a colon (:) and the filename. A suffix
of '.PAS' will be automatically added to the file name. Then
have at least one space and '*)'.
3. Pascal source files must reside on disk.
4. The output pseudo-code from the compile will be directed to
the same disk drive that the Pascal source resides on. It will
be created with a filename suffix of '.PCD'. If you have
multiple disk drives and the source and pcode will not both
fit on one disk, have a small file on the output disk with an
'include' for the source which resides on the other disk.
5. The hexadecimal offset of the pseudo instructions generated is
given at the left side of the output listing. This offset may
be useful for debugging purposes. It may be referred to when
looking at a program trace (see TRACEON in the Pascal
Definitions section of the manual provided to registered
users). It also may be referred to in case of an error message
or termination caused by pressing the BREAK key. The offset
shown may not always be accurate. If not exact, the values are
very close.
6. The name and stack offset of each variable defined is shown at
the end of the compile listing. The offset value is shown in
hexadecimal. Each stack entry is two bytes wide. The first
three stack entries are reserved for system use. Therefore,
the offset of the first variable will be 0003, which is
actually six bytes into the stack. If a variable is defined
within a procedure or function, the offset shown is relative
the beginning of that procedure or function.
7. The program is ready to run immediately after the compile is
finished. No linking is required. (Some Pascal systems require
linking of output code after the compile and before
execution).
8. Nested procedures are supported. You may define one procedure
within another.
9. Recursive procedures are supported. A procedure may call
itself. If variables are defined within the procedure, they
are cleared with each entry into the procedure and refreshed
upon exit from the recursive procedure call.
10. No forward references are allowed. A procedure may not be
referenced before it is defined. In most cases, nesting the
procedures will take care of this problem.
24
Draper Pascal 2.1 The Compiler
11. Double density disk drives are supported for both source and
pcode files. The pcode will be written to the same drive that
the initial source is taken from.
12. Only integer type parameters may be passed to procedures and
functions. Other types of data may be passed by using global
type variables setup at the beginning of the program (not
within a procedure or function).
13. A function may only return an integer type value. Procedures
do not return values.
14. Hexadecimal constants and literals are prefixed by dollar
signs ($).
15. To write out an integer in hexadecimal format, precede the
variable name with a percent sign (%).
16. A total of 170 compiler table entries may be used. One table
entry is used for each variable definition, procedure name,
function name, and parameter name used with procedures and
functions. Table entries for variables defined within
procedures are re-used following the 'END' for that procedure.
The number of table entries used within a compile is displayed
at the end of the output list from the Compiler.
17. The time needed to compile a program can be reduced by turning
off the ANTIC chip within the computer. This turns off the
display to the screen yet gives a fairly significant increase
to the Atari's internal speed. In a normal Pascal program, you
can have POKE(559,0) to turn it off and POKE(559,34) to turn
it back on. But a special compile time option is provided to
make use of this feature to speed up compiles. It is as
follows. Have a statement (*$S+*) to turn the ANTIC off
(increase speed), and use (*$S-*) to turn the ANTIC on (resume
normal speed). These options may appear anywhere within a
program. The ANTIC is automatically turned back on at compile
termination and at time of error (if any).
25
Draper Pascal 2.1 The Supervisor
The Supervisor
The Supervisor is a high performance machine language program
which simulates a pseudo 16-bit stack oriented computer. It
executes the pseudo code that is generated by the Compiler.
It is loaded into memory by disk operating system at the hex
location $1D7C, which is just above DOS in memory. It should work
with any DOS that allows a program to load at that address, such
as Atari DOS 2.1S, Atari DOS 2.5, or SpartaDOS version 2.x or
higher. A message will be displayed if the Supervisor cannot be
loaded at the proper location.
The disk filename for the Supervisor's object code is
'AUTORUN.SYS'. It may be renamed to anything you desire, such as
'PASCAL.COM', but will not be automatically loaded when the disk
is booted if the name is other than 'AUTORUN.SYS'. To start the
Pascal system from the DOS menu, use the 'L', binary load, option
to load 'AUTORUN.SYS' into memory. Execution will begin
automatically.
The Supervisor begins execution by loading and executing the
Pascal program 'INIT.PCD' from the default drive, which is always
disk drive 1 immediately after loading the Supervisor. 'INIT.PCD'
is the name of the main menu program. You may substitute any
compiled Pascal program of your own by naming it 'INIT.PCD'. In
this manner, you can have a true turnkey system where your program
begins execution after booting the disk.
After termination of each Pascal program, the Supervisor gives you
a choice of what to do next. You are prompted with the following
line:
<START>Repeat,<SELECT>Menu,<ESC>Exit
If you press the START key, your Pascal program will execute again
from the beginning. If you press the SELECT key, control will be
transfered to the main menu program (INIT.PCD). If you press the
ESC key, you will exit to the DOS utility menu. You also have two
other options at this point. They are both used for debugging
purposes. If you press CTRL-S (the 'S' key while holding down the
CTRL key), the stack values, at termination time, will be
displayed. If you press CTRL-T, the internal trace table, if
active, will be displayed. With either of these two debugging
options, you will be asked where the display should be sent by the
prompt 'WHERE? (FILESPEC)'. To see it on the screen, enter 'E:'.
It also may be sent to printer or disk by following normal
filespec naming conventions. If the display is sent to the screen,
you may stop the scrolling by use of the space bar. Press the ESC
key if you have seen enough and wish to return to the Supervisor
termination prompt. Any other key causes scrolling to continue as
normal.
26
Draper Pascal 2.1 Pascal Definitions
Pascal Definitions
Syntax is shown below for each of the Draper Pascal reserved
words. The complete manual provided to registered users, however,
contains COMPLETE definitions, COMPLETE sample programs
demonstrating the use of each reserved word, as well as BASIC
equivalents.
ABS FUNCTION ABS(Number):INTEGER;
ADDR FUNCTION ADDR(Var):INTEGER;
AND
ARCTAN FUNCTION ARCTAN(Var):REAL;
ARRAY ARRAY[Number1] OF Type
ARRAY[Number1,Number2] OF Type
ASC FUNCTION ASC(Cvar):INTEGER;
BEGIN
BLOAD PROCEDURE BLOAD(Program);
BOOLEAN
CALL PROCEDURE CALL(Address);
CASE CASE expr1 OF const1 : stmt1;
const2 : stmt2;
...
constn : stmtn
END;
CASE expr1 OF const1 : stmt1;
const2 : stmt2;
...
constn : stmtn
ELSE stmtx
END;
CHAR
CHR FUNCTION CHR(expr1):CHAR;
CLOSE PROCEDURE CLOSE(File);
COLOR PROCEDURE COLOR(Number);
27
Draper Pascal 2.1 Pascal Definitions
CONCAT PROCEDURE CONCAT(Parm1,Parm2,...):STRING;
CONST CONST name1=value1; name2=value2; ...
COPY FUNCTION COPY(Source,Index,Length) : STRING;
COS FUNCTION COS(Var):REAL;
CVTREAL FUNCTION CVTREAL(Ivar):REAL
DEG PROCEDURE DEG;
DELETE PROCEDURE DELETE(Source,Index,Size);
DIV
DOS PROCEDURE DOS;
DRAWTO PROCEDURE DRAWTO(X,Y);
DUMPSTK PROCEDURE DUMPSTK;
DVSTAT PROCEDURE DVSTAT(A,B,C,D);
END
EOF EOF(File);
EOLN EOLN(File);
EXIT PROCEDURE EXIT;
EXP FUNCTION EXP(Var):REAL;
EXP10 FUNCTION EXP10(Var):REAL;
FALSE
FILE
FOR FOR var := expr1 TO expr2 DO statement;
FOR var := expr1 DOWNTO expr2 DO statement;
FUNCTION
GOTOXY PROCEDURE GOTOXY(X,Y);
GRAPHICS PROCEDURE GRAPHICS(Number);
HIMEM PROCEDURE HIMEM(Value);
28
Draper Pascal 2.1 Pascal Definitions
IF IF expr1 THEN stmt1;
IF expr1 THEN stmt1 ELSE stmt2;
INSERT PROCEDURE INSERT(Source,Destination,Index);
INTEGER
IORESULT FUNCTION IORESULT:INTEGER;
KEYPRESS FUNCTION KEYPRESS:INTEGER;
LENGTH FUNCTION LENGTH(svar):INTEGER;
LN FUNCTION LN(Var):REAL;
LOCATE FUNCTION LOCATE(X,Y):INTEGER;
LOCK PROCEDURE LOCK(Filename);
LOG FUNCTION LOG(Var):REAL;
LPENH, LPENV FUNCTION LPENH:INTEGER;
FUNCTION LPENV:INTEGER;
MAXGRAPH PROCEDURE MAXGRAPH(Mode);
MOD
NOT
NOTE PROCEDURE NOTE(Iocbno,Sector,Byte);
ODD FUNCTION ODD(iexp);
OPEN PROCEDURE OPEN(Fileno,Aux1,Aux2,Filename);;
OPTIONKEY
OPTIONS OPTIONS(Opt1,Opt2,...,Optn);
OR
ORD FUNCTION ORD(Realvar):INTEGER;
PADDLE FUNCTION PADDLE(Number):INTEGER;
PEEK FUNCTION PEEK(Address):INTEGER;
PLOT PROCEDURE PLOT(X,Y);
POINT PROCEDURE POINT(Iocbno,Sector,Byte);
29
Draper Pascal 2.1 Pascal Definitions
POKE PROCEDURE POKE(Address,Value);
POS FUNCTION POS(Pattern,Source):INTEGER;
PROCEDURE PROCEDURE Name;
PROCEDURE Name(Parm1,Parm2,...,Parmn);
PROGRAM PROGRAM Name;
PTRIG FUNCTION PTRIG(Number):INTEGER;
PURGE PROCEDURE PURGE(Filespec);
RAD
READ, READLN PROCEDURE READ(File,Var1,Var2,...Varn);
REAL
RECORD
REPEAT REPEAT Stmt1; ... ;Stmtn UNTIL Condition;
RESET PROCEDURE RESET(File,Filespec);
REWRITE PROCEDURE REWRITE(File,Filespec);
RND FUNCTION RND(Iexp):INTEGER;
SELECTKEY
SETCOLOR PROCEDURE SETCOLOR(Register,Hue,Luminance);
SHL Expr1 SHL Expr2
SHR Expr1 SHR Expr2
SIN FUNCTION SIN(Var):REAL;
SOUND PROCEDURE SOUND(Voice,Pitch,Distortion,Volume);
SQR FUNCTION SQR(Var):REAL;
SQRT FUNCTION SQRT(Var):REAL;
STARTKEY
STATUS PROCEDURE STATUS(Iocbno,Ivar);
STICK FUNCTION STICK(Number):INTEGER;
30
Draper Pascal 2.1 Pascal Definitions
STR FUNCTION STR(Var):STRING;
STRIG FUNCTION STRIG(Number):INTEGER;
STRING
TRACEOFF PROCEDURE TRACEOFF;
TRACEON PROCEDURE TRACEON;
PROCEDURE TRACEON('Number);
TRUE
UNLOCK PROCEDURE UNLOCK(Filespec);
VAL FUNCTION VAL(Svar):INTEGER or REAL;
VAR VAR Name1,Name2,...,Namen : Type;
VAR Name1,Name2,...,Namen : ARRAY[Number]
OF Type;
WAIT PROCEDURE WAIT(Number);
WHILE WHILE Condition DO Statement;
WRITE WRITE(File,Expr1,Expr2,...);
WRITE(File,Expr1:Fldwdth...);
WRITE(File,Expr1:Fldwdth:Numdec...);
WRITELN WRITELN(File,Expr1,Expr2,...);
WRITELN(File,Expr1:Fldwdth...);
WRITELN(File,Expr1:Fldwdth:Numdec...);
XCTL PROCEDURE XCTL(Filespec);
XIO PROCEDURE XIO(Number,File,Aux1,Aux2,Filespec);
31
Draper Pascal 2.1 System Information
System Information
The Supervisor uses zero page locations $A0 - $BF. Locations $80 -
$9F are available for your use if desired. Various locations
between $D4 and $FD are used by the floating point routines. Page
six ($600 - $6FF) is available for your use and not used by the
Pascal system.
The Supervisor is loaded into memory by DOS at the address $1D7C.
If this memory location is not available, then an error message is
given, along with an explanation of the probable cause of the
problem. The pseudo code program to be executed is loaded in
memory immediately after the end of the Supervisor. The pseudo
machine stack extends from the end of the pseudo code program to
the MEMTOP position, just before screen memory.
Filename Descriptions
The files named below are included in this ARC file:
AUTORUN.SYS Supervisor object code
COMPILER.PCD Compiler pcode
EDITOR.PCD Editor pcode
INIT.PCD Main Menu pcode
INIT.PAS Main Menu Pascal source
EXPLNERR.PCD Error code explainor (used by Compiler)
RSVDWRDS.TXT Reserved word list (used by Compiler)
ERRORS.TXT Text for compile errors (used by
EXPLNERR.PCD)
RAMDISK1.DAT Ramdisk setup (See complete manual)
RAMDISK2.DAT Ramdisk setup (See complete manual)
RAMDISK3.DAT Ramdisk setup (See complete manual)
NOTITLE.OBJ Used to suppress title (See complete
manual)
SAMPLE1.PAS Kaleidoscope sample program source
SAMPLE2.PAS Roman numeral sample program source
PASCAL.DOC This introduction manual
32
Draper Pascal 2.1 Reserved Word List
Reserved Word List
ABS DEG FUNCTION ODD READLN STRING
ADDR DELETE GOTOXY OF REAL THEN
AND DIV GRAPHICS OPEN RECORD TO
ARCTAN DO HIMEM OPTIONKEY REPEAT TRACEOFF
ARRAY DOS IF OPTIONS RESET TRACEON
ASC DOWNTO INSERT OR REWRITE TRUE
BEGIN DRAWTO INTEGER ORD RND UNLOCK
BLOAD DUMPSTK IORESULT PADDLE SELECTKEY UNTIL
BOOLEAN DVSTAT KEYPRESS PEEK SETCOLOR VAL
CALL ELSE LENGTH PLOT SHL VAR
CASE END LN POINT SHR WAIT
CHAR EOF LOCATE POKE SIN WHILE
CHR EOLN LOCK POS SOUND WRITE
CLOSE EXIT LOG PROC SQR WRITELN
COLOR EXP LPENH PROCEDURE SQRT XCTL
CONCAT EXP10 LPENV PROGRAM STARTKEY XIO
CONST FALSE MAXGRAPH PTRIG STATUS
COPY FILE MOD PURGE STICK
COS FOR NOT RAD STR
CVTREAL FUNC NOTE READ STRIG
33
Draper Pascal 2.1 Operators
Operators
Operator Operation
________ _________
:= assignment
arithmetic:
+ addition
- subtraction
* multiplication
/ or DIV division
MOD modulo (remainder after
division)
Relational:
= equality
<> inequality
< less than
> greater than
<= less than or equal to
>= greater than or equal to
Logical:
OR
AND
NOT
34
Draper Pascal 2.1 Error Messages
Error Messages
COMPILE TIME ERROR MESSAGES
01: Compiler table overflow (max 170)
02: Number expected
03: '=' expected
04: Identifier expected
05: Constant type identifier, number, or string constant expected
06: 'BEGIN' expected
07: Too many nesting levels
08: ':' expected
09: '.' expected
10: ';' expected
11: Undeclared identifier
12: Invalid type of identifier
13: ':=' expected
14: 'END' expected
15: ';', 'ELSE', or 'END' expected
16: 'THEN' expected
17: '#' expected
18: 'DO' expected
19: '#' or FILE type identifier expected
20: '[' expected
21: ']' expected
22: ')' expected
23: Illegal factor or identifier type
24: INCLUDE file nesting too deep
25:
26: 'OF' expected
27: Mismatched data types
28: 'TO' or 'DOWNTO' expected
29: 'UNTIL' expected
30: Range error
31: '(' expected
32: ',' expected
33: Literal too long or missing end quote (')
34: 'END' but no RECORD started
35: Incorrect number of parameters
36: INTEGER type identifier expected
37: STRING type identifier expected
38: REAL type identifier expected
39: CHAR type identifier expected
40: FILE type identifier expected
41: HEX type identifier expected
42: STRING constant expected
35
Draper Pascal 2.1 Error Messages
EXECUTION TIME ERROR MESSAGES
INDEX TOO HIGH
This message occurs if an attempt is made to
store a string array element into an occurance
that is higher than defined for the variable.
For example, if you tried to store the
twentieth entry of an array that was only
defined to hold ten occurances, you would get
the message. This message only applies to
string arrays since other array types are not
checked for valid occurance numbers.
UNABLE TO OPEN DEBUG IOCB (7)
This message is issued if the list output
device you specify in response to the 'WHERE?
(FILESPEC)' prompt cannot be opened. The
prompt is issued only for the debug features
trace and stack display.
CIO ERROR xxx FOR IOCB # y
Some kind of Input-Output operation was
performed which resulted in an abnormal return
code from the Atari operating system. Refer to
your BASIC or DOS manual for the meaning of
the error number 'xxx'. 'y' is the IOCB number
which the error occured on. Note that this
message will not be printed if OPTIONS(0) is
in effect. In this case it is your
responsibility to check the return code by
interrogating IORESULT after each I/O type
instruction.
AT OFFSET
This message accompanies some other error
message and refers to the offset within the
pseudo code of the instruction that had the
error. Refer to the offset shown on your
compile listing to determine the Pascal
instruction that experienced the error.
36
Draper Pascal 2.1 Error Messages
STOPPED BY <BREAK> KEY
This message indicates that execution of the
program was stopped because the BREAK key was
pressed. The offset of the instruction
executing is shown in the 'AT OFFSET' message.
Note that this message will not occur (and the
program will not stop after BREAK is pressed)
if OPTIONS(4) is in effect.
INSUFFICIENT MEMORY
This message indicates that an attempt was
made to increase the value of the stack
pointer to a value which would overlay screen
memory or the trace buffer, if the trace was
active. It may also be caused by manipulation
of a record without sufficient room between
the top of the stack and the top of available
memory (MEMTOP) to temporarily hold it.
INVALID OPCODE
This message should not occur. It indicates
that a pseudo instruction was encountered
which is invalid. If you get this message, it
means that your '.PCD' file has been corrupted
somehow or an XCTL was made to a file that was
not a pseudo code file. To correct, re-compile
the program in question. It may also occur if
you attempt to run a Draper Pascal program
which was compiled under a previous release of
this software.
37
Draper Pascal 2.1 Registration Form
Registration Form
When you register for a fee of only $15.00, you will receive a
copy of the latest version of the Draper Pascal manual. Also, if
a later version of the software is more current than the version
you are registering, you will receive a diskette containing it.
In addition to all relative information in this manual, the
complete manual provided to registered users contains the
following:
* Complete Draper Pascal reserved word definitions
* Complete Draper Pascal example programs demonstrating the use
of each reserved word
* BASIC equivalents for each reserved word, where applicable
* Information on setup and use of a Ramdisk for Draper Pascal.
After proper initialization, the Editor will take less than two
seconds to load and the Compiler will take less than three
seconds. Also, the default drive will be automatically set to
the Ramdisk.
* A royalty-free, non-exclusive license to allow you to
distribute software developed using Draper Pascal
* Complete Draper Pascal source listings for the Editor, Main
Menu program, Ramdisk initialization program, and sample
programs
* Editor command summary
* Information on how to suppress the title screen from being
displayed
* Trace format descriptions
* Internal data format descriptions
* Notes on printer usage with Draper Pascal
* Technical support, by mail, at no charge
If you purchased Draper Pascal directly from Draper Software in
your own name, then your copy is already registered and you will
recieve all the benefits of registration. You do not need to send
in a registration form.
If you received Draper Pascal some other way, you may register
your copy by filling out the following form and mailing it to the
listed address along with your check or money order.
38
Draper Pascal 2.1 Registration Form
================================================================
Draper Pascal 2.1 Registration Form
Mail payment to: Draper Software
307 Forest Grove Drive
Richardson, TX 75080-1939
Texas residents: Please add 8% tax.
Note: Please allow three to five weeks for delivery.
NAME _________________________________________
COMPANY (if any) ______________________________
ADDRESS ______________________________________
CITY/STATE ___________________________________
ZIP __________________
Where did you obtain this copy of Draper Pascal?
_________________________________________________
_________________________________________________
_________________________________________________
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