COPYRIGHT © 1979 by 
Technical Systems Consultants, Inc. 
111 Providence Road 
Chapel Hill, North Carolina 27514 
All Rights Reserved 


 COPYRIGHT INFORMATION 

This entire manual is provided for the personal use and enjoyment of the purchaser. Its 
contents are copyrighted by Technical Systems Consultants, Inc., and reproduction, in 
whole or in part, by any means is prohibited. Use of this program, or any part thereof, 
for any purpose other than single end use by the purchaser is prohibited.

 DISCLAIMER 

The supplied software is intended for use only as described in this manual. Use of 
undocumented features or parameters may cause unpredictable results for which Technical 
Systems Consultants, Inc. cannot assume responsibility. Although every effort has been 
made to make the supplied software and its documentation as accurate and functional as 
possible, Technical Systems Consultants, Inc. will not assume responsibility for any 
damages incurred or generated by such material. Technical Systems Consultants, Inc. 
reserves the right to make changes in such material at any time without notice. 


 Index

 1. Introduction ....................... 2


 1.1 conventions .................. 3


 1.2 definitions .................. 3


 2. Getting the system started ......... 4


 3. Features ........................... 6


 3.1 variable names ............... 6


 3.2 line labels .................. 7


 3.3 continuation of lines ........ 7


 3.4 compiler options ............. 8


 4. Error messages ..................... 10


 5. Adapting to your system ............ 12 
Appendix .............................. 14 



BASIC PRECOMPILER User's Manual 

1. INTRODUCTION 
Technical Systems Consultants' BASIC PRECOMPILER (PC) and EXTENDED 
BASIC PRECOMPILER (XPC) are designed to give the BASIC user greater 
flexibility in writing programs, easier to read programs, and smaller 
'compiled' files. The precompilers accept BASIC source files and 
convert to BAsic Compile files (.BAC) similar to the COMPILE command in 
BASIC. This should not be confused with BASIC compilers that generate 
machine language code, because PC and XPC generate code that can only be 
used with BASIC. This is the manual of the precompiler for both BASIC 
and EXTENDED BASIC and for both the 6800 and 6809.

 PC and XPC execute in two passes and will accept any size file on 
the disk for input as long as enough memory is available for the symbol 
table. Two types of output can be generated. The first one is a source 
listing of the basic program complete with line numbered statements and 
any error messages. The second is the compiled version of the program 
ready to be executed by BASIC.

 It is assumed that the reader is familiar with BASIC so detailed 
programming examples are not given nor is the syntax of the BASIC 
language explained.

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 BASIC PRECOMPILER User's Manual 

1.1 Conventions 
As in the BASIC User's manuals the following conventions will be 
used. The statement or command being described will be printed in 
capital letters. Angle brackets (<>) will be used to enclose essential 
components of the statement. Square brackets ([]) will be used to 
enclose optional components.

 <essiental item> 
[optional item] 


1.2 Definitions 
LOGICAL LINE 
A logical line in BASIC can consist of one or more physical lines. 
It may also consist of one or more basic statements separated by 
either a back slash ('\') or a colon (':'). 

PHYSICAL LINE 
A physical line is defined to be one line on a terminal ending with 
a carriage return. It also can be thought of as one line in the 
editor. 

LETTERS 
The set of letters consists of the characters 'A' through 'Z' and 
'a' through 'z'. The underscore character ('_') is valid as a 
letter also. 

NUMBERS 
The set of numbers consists of the characters '0' through '9'. 

HEXADECIMAL NUMBERS 
Hexadecimal numbers will start with a dollar sign ('$') and be 
followed by four characters from the set of numbers and the set of 
letters 'A' to 'F'. 

SEPARATORS 
The set of separators consists of any character that is not a 
letter, number or an underscore.

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BASIC PRECOMPILER User's Manual 

2. GETTING THE SYSTEM STARTED 
Since there are not any built-in editing functions in the compilers 
-- you must have a previous created source file on disk before using PC 
or XPC. The source must must be a standard FLEX source file which is 
simply textual lines terminated with a carriage return. There should be 
no control characters in the source file except for the carriage return. 

THE FLEX COMMAND LINE

 The syntax for calling PC or XPC is as follows:

 PC <source file> [<compile file>] [+<options>]

 or

 XPC <source file> [<compile file>] [+<options>] 

Where all file names are standard FLEX file names and default to the 
current working drive. The <source file> is a previously edited file 
containing the BASIC source lines, <compile file> is optionally 
specified as the name of a file to contain the result of the 
compilation, and <options> is a list of options to be invoked when the 
compiler is called.

 The source file by default has an extension of .TXT as if it were 
generated by the Text Editor. Optionally one can specify a different 
extension (ie .BAS) or a drive other than the working drive (ie. 
1.PROG) by just including it in the file name. For example:

 +++PC PROG will default to PROG.TXT on the working drive

 +++PC PROG.BAS.1 over rides all filename defaults

 The binary file, if not specified, defaults to the same name as the 
source file but with the .BAC extension. Optionally, one may specify a 
different name by just including it in the command line. For example:

 +++PC PROG1.BAS P 

will use as source PROG1.BAS on the working drive and write the binary 
to P.BAC also on the working drive. If the file P.BAC already exists on 
the working drive PC will ask the user if the file should be deleted 
before starting. For example:

 +++PC PROG1.BAS P

 DELETE OLD BINARY (Y/N)? 

If N is typed after the prompt, PC will quit and return to FLEX. If Y

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 BASIC PRECOMPILER User's Manual 

is typed, the file will be deleted and PC will continue on its way. If 
anything else is typed you will be prompted again for either Y or N.

 Optionally, one may include compiler options on the command line. 
The list of options must start with a plus sign ('+'), may not have any 
imbedded spaces, and contain the following letters in any order. 

B 
Do not create the binary file. No binary file will be created even 
if a binary file name is specified. This is useful when compiling 
a program to check for any syntax errors or for a listing of the 
program. 

Suppress the source listing. If not specified, the compiler will 
print each line as it is read in pass two. Any lines containing 
errors will automatically be printed regardless of whether or not 
the option is specified. Also, imbedding a compiler $LIS or $NOL 
option into the source will turn on or off the source listing. 

S 
S has no meaning whatsoever. It is included just to be compatible 
with the ASMB command. 

N 
Turn off line numbers. By default, line numbers are printed at the 
beginning of each logical line. But if the source program already 
has line numbers, like a normal basic program, more line numbers 
would only be confusing. 

Y 
Yes, go ahead and delete the binary file. If binary is being 
generated and the file already exists then specifying Y will over 
ride the prompt to delete the file. 

Some examples:

 +++PC PROG1 +LY 
no listing, delete old binary

 +++PC PROG1.BAS +NB 
listing on, no line numbers or binary

 +++PC PROG1 T +SLY 
no listing, binary on T.BAC on the work drive, 
automatically delete existing binary file

 The compilers do not have a built-in method to output to a hardcopy 
device. However, this operation is available through I/O redirection in 
FLEX. For example:

 +++P PC PROG1 +B 

would cause the listing to be sent to whatever device was defined by the P 
command in FLEX. For further details of the P command see the FLEX 
User's Manual and the FLEX Advanced Programmer's Guide.

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BASIC PRECOMPILER User's Manual 

3. FEATURES 
Four things stand out as the main features of PC and XPC. They are:

 (1) unlimited length variable names; 
(2) unlimited length label names; 
(3) continuing logical lines across physical line boundaries; 
(4) pagination control for listings. 
Each feature will be discussed in detail below. 

3.1 Variable Names 
Variable names may be of any length and may contain letters, 
numbers, and the underscore character ('_'). The name cannot be a 
keyword (see appendix A for list of keywords), the first character must 
be a letter or an underscore, and the name must be terminated by a blank 
or separator. Also the name cannot start with the letters 'FN' unless 
it is a call to or definition of a USER DEFINED function. Lower case 
letters are automatically mapped into upper case, therefore the name 
'lower' is the same as the name 'LOWER'. Some examples of variable 
names are:

 THIS_IS_A_VARIABLE_NAME 
SO_IS_THIS 
THIS_IS_A_STRING_VARIABLE$ 
_SO_IS_THIS_$ 
this_is_too$ 
FUNCTION_IS_A_FUNCTION_NAME 
_THIS_IS_AN_INTEGER_VARIABLE% 
_SO_IS_THIS_% 
THIS_IS_A_DUPLICATE_NAME 
this_is_a_duplicate_name 


Some illegal variable names are:

 1_CANNOT_START_A_VARIABLE_NAME 
9CANNOT_START_A_VARIABLE_NAME_EITHER 
CLOSE variable names cannot be keywords

 Dummy variable names are an exception. They are limited to 30 
characters in length. Since the compiler must "remember" the dummy 
variable when defining the user defined function, a buffer of 30 
characters is set aside for the name. This is not really a restriction, 
since it is common practice to use a single character to define the 
dummy variable. For example:

 DEF FNCTION1(X) = SQR(X + X) 

Defines function 'FNCTION1' with dummy variable 'X'.

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 BASIC PRECOMPILER User's Manual 

3.2 Line Labels 
BASIC normally requires an integer line number on every source line 
of the program. PC and XPC, on the other hand, only require a label on 
a line that program control will be transferred to. Also, the label 
need not be an integer, it can be any contiguous series of characters 
consisting of letters, numbers and underscores. Any other character 
terminates the label name. All statement labels must begin in column 
one, and statements must start in column two or beyond. Some examples 
are:

 THIS_IS_A_LABEL REM THIS IS A REMARK STATEMENT WITH A LABEL 
1000 REM THAT WAS THE LABEL '1000' 
THIS_IS_A_LABEL_WITHOUT_A_STATEMENT 
0000 REM NOTE THAT 0000 IS A LEGAL LABEL NAME

 GOTO 0000 \REM IS A VALID STATEMENT; BUT 
GOTOOOO0 \REM DEFINES A VARIABLE 'GOTOOOOO' 

3.3 Continuation of Lines 
PC and XPC allow BASIC lines (logical lines) to be split across 
physical line boundaries or in other words, a logical line consists of 
one or more physical lines. To do so, just place a backslash ('\') 
before the carriage return. PC and XPC treat the back slash-carriage 
return on continued lines simply as a blank. This means that variable 
names and keywords cannot be continued onto the next line since the 
blank is a separator. Also, the total length of the logical line must 
not exceed 255 characters or the error message 'LINE TOO LONG' will be 
generated. It should be noted that multiple spaces are ignored except 
inside of strings where they are significant. For example:

 IF DELTA% <= GAMMA% THEN PRINT 'DELTA ='; DELTA% \<CR> 
ELSE PRINT 'GAMMA ='; GAMMA% <CR>

 * DEFINE RECORD I/O BUFFER 
FOR I=0 TO NUMBER_ELEMENTS :

 FIELD 1, I*ELEMENT_SIZE AS G$, \<CR> 
15 AS FIRST_NAME$(I), \<CR> 
15 AS LAST_NAME$(I), \<CR> 
09 AS SOC_SEC_NU$(I), \<CR> 
02 AS INDEX$(I) : \<CR>

 NEXT I <CR>

 In the first line of the example, the IF-THEN-ELSE statement is 
compiled as one logical line even though it is split across two physical 
lines. Notice that a REMark statement after the THEN portion would

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BASIC PRECOMPILER User's Manual 

cause the ELSE statement to be ignored, since REMarks stop at the end of 
the LOGICAL line. The next logical line is the line that begins with an 
asterisk in column one. This is a REMark line and is ignored by the 
compiler. The last logical line consists of seven physical lines 
starting with the FOR statement and ending with the NEXT statement. 
Even though seven physical lines are involved, only three basic 
statements are used. If more than one statement is on a logical line, 
the statement must be seperated by either a colon (:) or a backslash 
(\). A backslash-carriage return does not act as a statement 
terminator. 

3.4 Compiler Options 
As the above example shows, any line that starts in column one with 
a separator is considered to be a comment line. In most cases, a 
comment line is ignored by PC and XPC. If the comment starts with a 
dollar sign ('$') in column one then the line is checked to see if it is 
a compiler option line. The following options are recognized: 

TTL <string> 
TTL sets the program title to <string>. The title may be 0 to 35 
characters long. If the <string> is longer, anything past the 
35th character is ignored. The title string is printed left 
justified on the same line as the date and compiler name. 

STTL <string> 
STTL sets the program sub-title to <string>. The sub-title may be 
O to 80 characters long. If the <string> is longer than 80 
characters, anything past the 8Oth charcter is ignored. The 
sub-title string is printed left justified under the title line. 

PAG 
The PAG option causes a page eject to occur. Normally, a page 
eject is performed every 55 lines but by using the PAG option one 
can cause a premature page eject. See also Adapting to Your 
System. 

SPC <n> [, <m>] 
The SPC command causes <n> blank lines to be inserted into the 
listing. Optionally the <m> parameter can be specified which is a 
keep count. If there are less than <m> lines left on the page 
then instead of spacing <n> lines, a page eject is performed and 
processing of the space command is terminated. This is useful to 
prevent a block of lines from being split across a page.

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 BASIC PRECOMPILER User's Manual 

LIS 
LIS is used to turn on the listing option. If the list option is 
already on then the LIS option is ignored. 

NOL 
NOL is used to turn off the listing option. If the list option is 
already turned off then the NOL option is ignored. 

LIB <file name> 
The LIB option tells the compiler to start reading the source from 
an alternate file. The <file name> should be in the normal FLEX 
format, and will have the same defaults as the source file name 
did on the command line. A file that is being 'LIBed' in cannot 
have a LIB option in it. That is, LIB options cannot be nested or 
recursive. 

SCALE <n> 
The SCALE command is available only in XPC. It sets the SCALE 
factor to <n> where 0 <= n <= 6. The SCALE option must be the 
first line of the original source file. If an error occurs in the 
SCALE option the SCALE factor is set to zero. See the EXTENDED 
BASIC User's manual for use of the SCALE factor. 

Some examples using options are:

 $ SCALE 3 set scale factor to 3, on the first line 
$ TTL this is the title up to 35 chr long 
$ STTL this is the sub title, up to 80 characters long 
$ PAG perform a page eject 
$ SPC 3 skip 3 lines 
$ NOL turn listing off for FILE1 
$ LIB FILE1 read FILE1 
$ LIS Turn listing back on for FILE2 
$ LIB FILE2 read FILE2

 END

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BASIC PRECOMPILER User's Manual 

4. Error Messages 
There are two types of error messages that can be generated by the 
compilers. The first type is from errors found on the command line 
calling PC or XPC from FLEX. The errors are: 

ILLEGAL OPTION SPECIFIED 
An unknown option character was found after the plus sign. 

ILLEGAL FILE NAME 
A file name was specified that was not in the standard FLEX 
format. 

MEMORY OVERFLOW 
Not enough memory was available to insert a symbol into the symbol 
table area. This can mean that the program has too many symbols 
to compile or that the MEMEND value in FLEX was set too low. Each 
program label requires the number of characters in the label plus 
5 bytes for flags. Each variable requires the number of 
characters in the variable name plus 1 byte plus 8 bytes for 
double precision, 4 bytes for single precision, or 4 bytes for 
strings, arrays, and user defined functions. 

The second type of errors are source code errors. 

UNBALANCED PARENS 
An expression has unbalanced parentheses. 

UNRECOGNIZABLE CHARACTER 
A character was seen that has no meaning to the compilers. 

MISSING QUOTE 
A closing quote was missing from a string constant. Since strings 
cannot cross physical line boundaries, if an end of line is seen 
before a closing quote this error is generated. 

DUPLICATE LINE LABEL 
Two lines have the same label. 

UNDEFINED LINE LABEL 
A reference to a label that does not exist was made. 

BAD CONSTANT 
An error was detected when trying to convert an ASCII number to 
binary. The number could be too large, too small, or contain an 
illegal character. 

DUMMY VARIABLE NAME TOO LONG 
Dummy variable names can be a maximum of 30 characters long. 

ILLEGAL SCALE FACTOR 
This error is in XPC only. The SCALE factor was too large, too

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 BASIC PRECOMPILER User's Manual

 small, or the SCALE option was not on the first line of the 
original source file. 

NESTED 'LIB' FILES NOT ALLOWED 
A file being read in via 'LIB' had a 'LIB' option in it. 

LINE TOO LONG 
One of two things can cause this error. If the error occurred and 
went immediately back to FLEX then the input source was longer 
than 255 characters (including continued lines). If the error 
message was printed and the compiler continued on to the next 
line, then the binary generated for that line was greater than 255 
bytes.

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BASIC PRECOMPILER User's Manual 

5. 
Adapting to your system 
Since the precompilers run under the FLEX operating system, there is 
very little adapting to be done. 
constants that the user can change;
None the less, there are three 
(1) the page eject string that is sent to a printer, 
(2) the number of lines on a page and, 
(3) the number of blank lines at the top of a page. 
The page eject string is sent to the printer to position the print 

head to the top of the next page. The eject string consists of a 
carriage return, line feed, form feed, and three null characters 
terminated by an ETX ($0004) character. The user may change the first 
six characters to anything else as long as the string is no more than 
six characters long and is terminated by the ETX character. One can 
disable the page eject string completely by placing an ETX as the first 
character of the string.

 The page size is the number of lines to be printed on a page before 
a page eject is to be performed. Initially, this is set to 55 lines. 
That is, the page is assumed to be 55 lines long PLUS the number of 
lines defined by the margin count PLUS five lines for the page heading. 
The margin count is initially set to 3. This means, after the page 
eject is performed three blank lines are printed. Then the title and 
sub-title lines are printed followed by three blank lines. Then 55 
lines of source followed by a page eject and so on and so forth.

 It should be noted that printing the page eject string is suppressed 
if output is going to the terminal. So if you are listing a program at 
a terminal that understands form feeds, the page eject won't clear the 
screen on every new page.

 The precompilers use as end of memory the address MEMEND defined in 
FLEX. As the precompilers read in source, labels and variable names are 
put in a symbol table. The symbol table starts at the end of the 
program and "grows" towards the end of memory. As a consequence, any 
other program to be kept in memory with the precompilers must be higher 
(read greater) than the address stored at MEMEND. The address of MEMEND 
in FLEX 1.0 and FLEX 2.0 is $AC2B, and MEMEND in FLEX 9.0 is $CC2B. 

For all versions of the precompiler the constants are located at:

 EJECT STRING $0002

 PAGE SIZE $0009

 MARGIN COUNT $OOOA 

To change any of these constants do the following:

 load the precompiler into memory with FLEX's GET command, 
go into your systems monitor using FLEX's MON command,

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 BASIC PRECOMPILER User's Manual

 change the constant(s), 
go back into FLEX at the warm start entry point 
($ADO3 for FLEX 1.0 and FLEX 2.0, 
$CDO3 for FLEX 9.0), 
save the precompiler back out on the disk using FLEX's SAVE command, 
where the syntax is: 
SAVE <file name> <start address> <end address> <transfer address> 
and you have a new version of the precompiler. 

The following table defines the start, end and transfer 
addresses for each precompiler.

 precompiler start end transfer 
address address address 
-------------------------------PC 
for 6800 $0002 $12FF $0100 
XPC for 6800 $0002 $16FF $0100 
PC for 6809 $0000 $12FF $0000 
XPC for 6809 $0000 $16FF $0000

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BASIC PRECOMPILER User's Manual 

Appendix 
The following is a list of all keywords defined in PC.

 ABS GOSUB 
AND GOTO PTR 
AS HEX PUT 
ASC IF READ 
ATN INPUT RECORD 
CHAIN INT REM 
CHR$ KILL RENAME 
CLOSE LEFT$ RESTORE 
COS LEN RESUME 
CVT$F LET RETURN 
CVTF$ LINE RIGHT$ 
DATA LOG RND 
DEF LSET RSET 
DIM MID$ SGN 
ELSE NEW SIN 
END NEXT SPC 
ERL NOT SQR 
ERR OLD STEP 
ERROR ON STOP 
EXEC OPEN STR$ 
EXP OR TAB 
FIELD PEEK TAN 
FN PI THEN 
FOR POKE TO 
FRE P0S USR 
GET PRINT VAL

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BASIC PRECOMPILER User's Manual 

The following is a list of all keywords defined in XPC.

 ABS FOR POS 
AND FRE PRINT 
AS GET PTR 
ASC GOSUB PUT 
ATN GOTO READ 
CHAIN HEX RECORD 
CHR$ IF REM 
CLOSE INCH$ RENAME 
COS INPUT RESTORE 
CVT$2 INSTR RESUME 
CVT$F INT RETURN 
CVT2$ KILL RIGHT$ 
CVTF$ LEFT$ RND 
DATA LEN RSET 
DATE$ LET SGN 
DEF LINE SIN 
DIGITS LOG SPC 
DIM LSET SQR 
DPEEK MID$ STEP 
DPOKE NEW STOP 
ELSE NEXT STR$ 
END NOT SWAP 
ERL OLD TAB 
ERR ON TAN 
ERROR OPEN THEN 
EXEC OR TO 
EXP PEEK USING 
FIELD PI USR 
FN POKE VAL