Inhoud
 

• Inleiding
• Statements and functions
• Program heading
• Multi-dimensional arrays
• String-functions
• Expanding the P-Charme Interpreter
• Error Messages
• NL version

AUTO - first line 10, each next one 10 higher.
AUTO 40 - first line 40, each next one 10 higher.
AUTO ,20 - first line 10, each next one 20 higher.
AUTO 100,100 - first line 100, each next one 100 higher.

BEEP <expr>,<expr>

10 CASE J-48 OF
20 2 PRINT "THIS IS EVEN"'
30 3 PRINT "THIS IS "
40 PRINT "ODD"'
50 1 PRINT "J = 49"'
60 CEND

10 CASE $A OF
20"SWEET" PRINT "NICE"'
30"BORING" PRINT "DULL"'
40$A PRINT "NO IDEA"'
50 CEND

If a case expression does not equal a case label, program execution is resumed right behind CEND. In the second example, the case label at line 40 always satisfies, and is therefore executed if the others do not. CASE statements may not be nested.

COPY expr, expr, expr

The first expression is the start address, the second is the end address of the area that is to be copied. The last expression is the destination memory address. If this one is within the boundaries of the source area, the COPY statement effectively is a FILL command. For example

COPY #2000,#3000,#2004

The result of this command is the the area between 32000 and 33004 repeatedly contains the same four bytes.

COS 0 - 300 baud
COS 1 - 1200 baud

DEL 200,300 - Delete lines 200 to 300.
DEL /REM/,300L - Lines 0 to 300, containing the text 'REM'.
DEL /STOP/V - All lines that contain the text 'STOP'.
DEL - Delete all lines (be careful!).

If the Veto option (V) is selected, a line is printed on screen first and a query will be made Y/N? There are several possible answers:

Y - YES proceed with the operation,
N - NO do not execute the operation,
C - CONTINUE proceed with the operation and disable the veto option,
L - LIST execute the operation and go on without the veto
option, however, do list all the lines that are changed,
S - SKIP do not execute the operation and go on to the next line,
ESC do not proceed with the operation and go back to direct mode.

Syntax is:

 EVEN (factor)

10 PROGRAM FTEST
20
30 FUNCTION ADD(A,B)
40 ADD=A+B
50 FEND
60
70 PRINT 2*ADD(5,6)
80 END

Recursive functions are allowed as well:

FUNCTION GCD(M,N)
XIF N=0 THEN GCD=M
ELSE GCD=GCD(N,M%N)
FEND

It is NOT allowed to used DIM inside functions and procedures.

HEX <expr>

HTAB 16

DO
INKEY A
PRINT $A
UNTIL A=CH"."

INSTR (string var,string right)

The brackets ( and ) are obligatory. The functions starts seaching in the first string for the second string. If found, INSTR is assigned the value of the position, otherwise it's zero.
INSTR may also be used in a logical expression. Examples:

P=INSTR($A,"HALLO")
R=INSTR($B+6,$C); REM search from 6th position in $B onwards.
IF INSTR($D,$E) THEN PRINT "FOUND"'

ODD (factor)

 10 INPUT S
20 ON S GOSUB 100,110,50,a,70
30 PRINT"*"'
40 GOTO 10
50 PRINT "THREE";RETURN
70 PRINT "FIVE";RETURN
80aPRINT "FOUR";RETURN
100 PRINT "ONE";RETURN
110 PRINT "TWO";RETURN

Examples:

 10 PROGRAM EXAMPLE
20
30 PROC FIX-PRINT (%A),Z,@
40 Z=%(%A*1000+5)/10;PRINT Z/100
50 @=0;Z=Z%100
60 PRINT "."Z/10,Z%10
70 PEND
80
90 @=11
100 FOR I=1 TO 5
110 READ %F
120 FPRINT %F;FIX-PRINT(%F)
130 PRINT'
140 NEXT I
150 END
160
170 DATA 10,1/3,2/3,10.9999,0

Herein %A is a value parameter. Z and @ are local variables.

 10 PROGRAM EXTREME
20
30 PROC MINMAX (A,B:G,S)
40 XIF A>B THEN G=A
50 ELSE G=B
60 XIF A <B THEN S=A
70 ELSE S=B
80 PEND
90
100 MINMAX(3,7,X,Y);PRINT X,Y'
110 A=1;B=2;G=3;K=4
120 MINMAX(G,12,X,Y);PRINT X,Y'
130 PRINT A,B,G,K'
140 END

Herein A and B are value parameters. G and S are ouput variables.
The output of the program is:

 7 3
12 3
1 2 3 4

Recursion is allowed as well. Example:

PROC STAR(N)
IF N>1 PRINT "*";STAR(N-1)
IF N=1 PRINT "*"
PEND

It is NOT allowed to used DIM inside functions and procedures.

1. Automatical RESTORE at the start of the program,
2. Initialization of procedures and functions,
3. Initialization of built-in functions (INSTR, EVEN etc),
4. Initialization of error pointer routines,
5. Initialization of multi-dimensional arrays,
6. Initialization of WHILE loops,
7. Recognition for the CAT statement.

Item 2 effectively fills the area #28DD-#28FF with #00. This area is NOT used by the floating point ROM. For Item 3, 4 and 5 the BRKVEC is changed for the duration of the program. A correct program name begins with two different characters. Here are some examples:

10 PROGRAM TEST VERSIE IV - the name here is 'TEST'
10 PROGRAM CRC-TEST - the name here is 'CRC-TEST'
10 PROGRAM QS(QUICK START) - the name here is 'QS'
10 PROGRAM -A Anemometer - the name here is '-A'

If the program is resident in the memory area #1000-#9FFF and if there's one space between the NOT abreviated statement PROGRAM and the line number the program name is automatically promoted to a statement.

Typing a program name results in searching the memory for that program, initializing the labels, clearing the FOR-NEXT, DO-UNTIL and GOSUB-stacks, setting the value of TOP and starting the program.

READ A,B,%A,%B,$T,DD(12),%FF(3,4)

RESTORE
RESTORE 160
RESTORE a

VTAB <expr>

XIF...THEN...ELSE constructions may be nested unlimited. Example:

10 XIF A+9=B-2 THEN I=1
20 Z=S?I
30 S?I=S?J
40 XIF %X=PI THEN PRINT '"PI="
60 PRINT "3.1415"'
70 ELSE PRINT'"NO PI"'
80 ELSE I=2
90 PRINT I'

Note that the THEN part may be spread over more than one line,
and the ELSE part can take no more than one line.

/REM/ - searches for the text 'REM' in the entire program,
/STOP/200, - searches 'STOP' from line 200 onwards,
/$A/,1000 - searches '$A' until line 1000.

/ Change text

With this command text can be sought and replaced. Examples:

/A$/$A/ - replace 'A$' by '$A',
/STEP -1/STEP 1/V - replace 'STEP -1' by 'STEP 1' with veto,
/ //L - remove all spaces with the list option
/DIM/FDIM/,100V - replace 'DIM' by 'FDIM' in the lines 0 to 100 with
the veto option.