| ABS |
A function giving the absolute
value of its argument.
Example:PRINT ABS(4),ABS(-3.2)
4 3.2
|
| ACS |
A function giving the arc cosine
of its argument in radians. |
| ADVAL |
Not implemented. |
| AND |
An operator that performs
bit-by-bit ANDing of its two arguments. It can be used as
a logical operator in TRUE/FALSE contexts.
Examples:
A%=X% AND 3
IF A%=2 AND B%=3 THEN 110 |
| ASC |
A function returning the ASCII
value of the first character of the argument string. If
the string is null then -l will be returned. |
| ASN |
A function giving the arc sine of
its argument in radians. |
| ATN |
A function giving the arc tangent
of its argument in radians. |
| AUTO |
A command allowing the user to
enter BASIC lines in sequence with the line numbers
provided automatically. AUTO mode is left by pressing ESC. There are two
optional arguments: the starting line number (default 10)
and the step size (between 1 and 255, default 10).
Examples:
AUTO starts at 10 with step 10
AUTO 100 starts at 100 with step 10
AUTO 100,1 starts at 100 with step 1
AUTO ,2 starts at 10 with step 2 |
| BGET# |
A function which gets a byte from
the file whose channel number is the first argument. Note
the normal ATOM COS constraints apply, i.e. there is no
buffering and room must be allowed between bytes on PUTting to
allow processing during GETting.
Example:
E=BGET#HANDLE% |
| BPUT# |
A statement which puts a byte to
the file whose channel number is the first argument. The
second argument's least significant byte is sent. Note
the comments for BGET*.
Examples:
BPUT#HANDLE%,32
BPUT#HANDLE%,A%/256 |
| CALL |
A statement to call a piece of
machine code. CALL initialises a control block at address hex
0600 in store to contain the number of parameters and
pointers to each parameter with an attached type. The
processor's A, X, and Y registers and the C carry flag
are initialised to the least-significant bytes of A%, X% and Y%
respectively and the least-significant bit of C%. See also
USR. Parameter types are:
| 0 |
byte e.g. ?A% |
| 4 |
word e.g. !A%
or A% |
| 5 |
real e.g. A |
| 128 |
fixed string e.g. $A%
terminated by CHR$13 |
| 129 |
movable string e.g. A$ |
The value given is the absolute
address of the item, except in the case of moveable
strings (code 129) where the address is that of the start
of a parameter block containing start address, maximum
length, and current length of the string.
Examples:
CALL &FFE3
CALL MULDIV,A,B,C,D
|
| CHAIN |
A statement which will load and
run the program whose name is specified in the argument.
All variables except @% to Z% are CLEARed.
Examples:
CHAIN "PROG1"
CHAIN A$ |
| CHR$ |
A string function returning a
string of length 1 containing the ASCII character
specified by the least significant byte of the numeric
argument.
Example:
PRINT CHR$(65)
A |
| CLEAR |
A statement which clears all the
dynamic variables, including arrays. The variables A% to Z% and @% are
static and are unaffected. |
| CLG |
A statement that clears the
current graphics area.
It is equivalent to a MODE statement in the current mode. |
| CLOSE# |
A dummy statement whose normal
function is not required by the ATOM COS. |
| CLS |
A statement that clears the
current text area.
It is equivalent to PRINT
CHR$12; |
| COLOUR |
Not implemented. |
| COS |
A function giving the cosine of
its radian argument. |
| COUNT |
A function returning the number of
characters printed since the last newline. |
| DATA |
A program object which must
precede all lists of data for READ. String
values may be quoted or unquoted as for INPUT, and
the numeric values may include calculation so long as no
reserved words are included.
Example:
DATA
FRANCIS,16,"JOHN ",15,"JULIE ",15 |
| DEF |
A program object which introduces
the definition of a user function FN or a user
procedure PROC. If encountered at execution then the rest
of the line is ignored so that single-line definitions
can be put anywhere in the program. Multiple-line
definitions must not be executed: it is recommended that
they are placed at the end of the main program text.
There is no speed advantage gained in placing them at the
start of the program. Example:
DEF
FNMEAN(Vl,V2)=(Vl,V2)/2
|
| DEG |
A function which converts radians
to degrees. |
| DELETE |
A command which deletes a group of
lines from the program. The two arguments indicete the
first and last lines of the group respectively.
Examples:
DELETE 10,15 delete lines 10 to 15
DELETE 0,20 delete up to line 20
DELETE 20,32767 delete all lines after 19 |
| DIM |
A statement which declares arrays.
Arrays must be declared before use. Integer, real and
string arrays may be multi-dimensional. The extents in
each dimension are specified as a bracketed list of
values separated by commas. DIM sets all elements in the
array to 0 or null, depending on type. Arrays may not be
redimensioned. By following the integer name with an
unbracketed extent value, DIM can also be used to
dimension integers to point at an area of memory which
the interpreter will not then use. This can be used for
positioned strings, data structures, machine code etc.
Example:
DIM
A(20),A$(2,4),A%(3,4,5,6),MC% 100 |
| DIV |
A binary operation giving integer
division. |
| DRAW |
A statement to draw a line to the
point specified by its two arguments in the current
graphics foreground colour. It is equivalent to PLOT5. |
| ELSE |
A statement indicating the start
of instructions to be executed if, in an IF structure,
the condition is FALSE, or in an ON structure, the tested value is
out-of-range.
Examples:
IF A=B THEN B=C ELSE B=D
ON A% GOTO 100,110,130 ELSE 500 |
| END |
A statement that terminates
execution of the program and returns the interpreter to
direct mode. There is no restriction on the number and
position of END statements in a program. |
| ENDPROC |
A statement denoting the end of a
procedure. The values of all LOCAL
variables and the dummy arguments are restored at ENDPROC and
the program returns to the statement after the calling
statement. |
| ENVELOPE |
Not implemented. |
| EOF |
Not implemented. |
| EOR |
An operator that performs
bit-by-bit exclusive-OR of its two arguments. It can also
be used as a logical operator in TRUE/FALSE contexts.
Examples:
X% = B% EOR 4
IF A=2 EOR B=3 THEN 110 |
| ERL |
A function returning the number of
the line where the last error occurred.
Errors in direct mode give the value 0. |
| ERR |
A function returning the error
code number of the last error. |
| ERROR |
See ON. |
| EVAL |
A function which applies the
interpreter's expression evaluation program to the
contents of the argument string. |
| EXP |
A function returning 'e' to the
power of the argument. |
| EXT# |
Not implemented. |
| FALSE |
A pseudo-variable with the value
-1, for use in logical expressions. |
| FN |
A reserved word used at the start
of all user declared functions. A function may be defined
with any number of arguments of any type, and may return
(using =) a string or numeric quantity. A function
definition is terminated by '=' used in
the statement position. The values of the dummy arguments
are set to those of the formal arguments when the
function is called.
Examples:
DEF
FNMEAN(Ql,Q2,Q3,Q4)=(Ql+Q2+Q3+Q4)/4
DEF FNFACTORIAL(N) IF N<2 THEN =1
ELSE =FNFACTORIAL(N-l )*N
DEF FNREVERSE(A$) LOCALB$,Z%
FOR Z% = l TO LEN (A$):
$=MID$(A$, Z%, l)+B$:NEXT:=B$ |
| FOR |
A statement initialising a FOR ... NEXT
loop. The loop is executed at least once. Any numeric
assignable item may be used as the control variable.
Integer control variables are three times quicker than
real variables at the NEXT statement and also much faster when
indexing an array.
Examples:
FOR A=0 TO 9
FOR A%=0 TO 9
FOR A(2,3,l) = 0 TO 9 |
| GCOL |
Not implemented. |
| GET |
A function that returns the ASCII
code of the next character from the input stream, waiting
for a key-press if necessary. |
| GET$ |
A function that returns the next
character from the input stream as a string, waiting for
a key-press if necessary. |
| GOSUB |
As GOTO but allows RETURN. GOSUBs may be nested to a maximum depth of 26. |
| GOTO |
A statement which transfers
execution to the line indicated by its argument, which
may be a constant number or calculated value. |
| HIMEM |
A pseudo-variable which sets and
gives the maximum address used by the interpreter. |
| IF |
Part of the conditional IF ... THEN ... ELSE statement. It introduces a logical
expression, the value of which determines whether the
following statements or those after the next optional ELSE, are to
be executed.
Examples:
IF A=B THEN 110
IF A<C OR A>D GOTO 110
IF A>C AND C>=D THEN GOTO 110
IF A<Q PRINT "I THINK IT IS LESS"
IF A>Q THEN PRINT "I THINK IT IS GREATER"
IF A>=Q THEN PRINT "GREATER OR EQUAL" : END |
| INKEY |
A function that performs a GET but
waits for a maximum of n clock ticks where n is the
argument. At the end of this period, -l is returned. INKEY of
negative numbers is not supported.
Examples:
NINKEY (0)
N$=INKEY$ (100) |
| INKEY$ |
A function that performs a GET$ but
waits for a maximum of n clock ticks where n is the
argument. At the end of this period, -l is returned. INKEY$ of
negative numbers is not supported. |
| INPUT |
A statement to input values from
the keyboard.
Example:
INPUT A,B,C,D$, "WHO
ARE YOU", W$, "NAME" R$
If items are not immediately preceded by a printable
string (even if null) then a "7" will be
printed as a prompt. Items A, B, C, D$
in the above example can have their answers returned on
one to four lines, separate items being separated by
commas. Extra items will be ignored. Then WHO ARE YOU?
is printed (the question mark comes from the comma) and W$ is input,
then NAME is printed and R$ is input.
The statement INPUT A is exactly equivalent to INPUT A$:A = VAL(A$). Leading spaces will be removed from input,
but not trailing spaces. Strings in quoted form are taken
as they are, with a possible error occurring for a
missing closing quote. |
| INPUTLINE |
A statement of identical syntax to
INPUT which uses a new line for each item to be
input. The item input is taken as is. |
| INPUT# |
A statement which reads internal
forms from tape and puts them in the specified items. The
first argument is the channel number.
Example:
INPUT#E A,B,C,D$,E$,F$ |
| LNSTR |
A function which returns the
position of a sub-string within a string, optionally
starting the search at a specified place in the string.
Examples:
INSTR(A$,B$)
INSTR(A$,B$,Z%) |
| INT |
A function truncating a real
number to the lower integer. |
| LEFT$ |
A string function which returns
the left n characters of the string. If there are
insufficient characters in the string then all are
returned.
Examples:
LEFT$(A$,2)
LEFT$(RIGHT$(A$,3),2) |
| LEN |
A function which returns the
length of the argument string.
Examples:
LENA$
LEN$(A%+6) |
| LET |
An optional assignment statement. |
| LIST |
A command which causes lines of
the current program to be listed out with the automatic
formatting options specified by LISTO. The
command can be followed by start and finish line numbers,
separated by a comma.
Examples:
LIST
LIST ,l00
LIST 100,500
Note that L. is a convenient abbreviation for LIST. |
| LISTO |
A command which sets options for
the format of a LISTed program. LISTO takes an integer in the range 0 to 7. The
three bits have the following effects when set:
Bit Effect
0 A single space is printed after the line number on each
line.
1 A double space is printed out n times after the line
number,
where n is the current level of nested FOR ... NEXT
loops.
2 A double space is printed out m times after the line
number, where m is the current level of nested REPEAT ... UNTIL loops. Note that n and m are set according
to the lines actually listed out so far. It is useful to
set LISTO 0 when doing a lot of cursor editing. |
| LN |
A function giving the natural
logarithm of its argument. |
| LOAD |
A command which loads a new
program from a file and CLEARs the variables of the old program.
Example:
LOAD "PRIMES" |
| LOCAL |
A statement which saves the values
of its arguments in such a way that they will be restored
at = or ENDPROC. The arguments are set to zero or null. It
can only be used inside a FN or PROC. See FN for an example. |
| LOG |
A function giving the common (base
10) logarithm of its argument. |
| LOMEM |
A pseudo-variable which controls
where in memory dynamic variables and dimensioned arrays
are to be placed. The default is TOP, the
first free address after the end of the program. |
| MID$ |
A string function which extracts a
sub-string from the middle of its argument string. The
second argument specifies the start position of the
sub-string, and the third its length. If the length is
omitted or there are insufficient characters in the
string then all from the start position onwards are
returned.
Examples:
MID$( A$, Z, X)
MID$( A$, Z) |
| MOD |
A binary operation giving the
signed remainder of the integer division. MOD is defined
such that:
A MOD B = A - (A DIV B) *
B
Example:
A% = B% MOD C% |
| MODE |
A statement which selects the
specified display screen mode (0-7), and clears the
screen. The relationship between BBC BASIC modes and the
normal ATOM modes is as follows:
| BBC |
ATOM |
| 0-3 |
4 |
| 4 |
3 |
| 5 |
2 |
| 6 |
1 |
| 7 |
0 |
MODE
cannot be used inside a PROC or FN
Examples:
MODE 7
MODE A
|
| MOVE |
A statement to move the graphics
cursor to the specified co-ordinates.
It is equivalent to PLOT4. |
| NEW |
A command which initialises the
interpreter for a new program to be typed in.
The old program may be recovered with the OLD command
provided no errors have occurred and no new lines have
been typed in. |
| NEXT |
The statement terminating FOR ... NEXT
loops. NEXT takes an optional control variable: if
present then FOR ... NEXT loops may be 'popped' in an attempt to
match to the correct FOR statement. |
| NOT |
A high priority unary operator
equivalent to unary minus.
Examples:
IF NOT(A=B AND C=D) THEN
2100
A% = NOT B% AND C% |
| OFF |
A program object used to re-enable
the default error handler.
Example:
ON ERROR OFF
See ON. |
| OLD |
A command which undoes the effect
of NEW, provided no new lines have been typed in
and no new variables have been created. |
| ON |
A statement controlling a
multi-way switch or error trapping. When used in one of
the forms:
ON <expression>
GOTO ...
ON <expression> GOSUB ...
the structure is followed by a list of line numbers
separated by commas, optionally followed by ELSE and one
or more statements. The integer value of the expression
selects the line number to be used, with the ELSE
statements being executed if the corresponding line
number is not provided. The values in the list are
skipped without calculation but it will get confused by ASC"," appearing.
ON can also be used to trap errors:ON ERROR ...
The statements following ON ERROR are
executed whenever a BASIC error occurs.
ON ERROR OFF re-enables the default error handler.
Examples:
ON A% GOTO
10,20,30,30:ELSE PRINT "Illegal"
ON B% GOSUB 100,20a,C+200:ELSE PRINT "What? "
ON ERROR PRINT "Suicide": END
ON ERROR GOTO 100
ON ERROR OFF
|
| OPENIN |
A dummy function which normally
opens the named file for input and updating and returns
the channel number of the file. The ATOM COS only allows
one open file (for input or output), and this function
just returns 13 as the channel number.
Example:
H%=OPENIN
"DATA" |
| OPENOUT |
A dummy function which normally
opens the named file for output and returns the channel
number of the file. The ATOM COS only allows one open
file, and this function just returns 13 as the channel
number.
Example:
H%=OPENOUT
"DATA" |
| OPT |
An assembler pseudo-operation
controlling output to the screen during assembly. OPT is
followed by an expression, the two least-significant bits
of which have the following effects when set:
Bit Effect
0 assembler listing on
1 assembler errors on
The default OPT is 3.
|
| OR |
An operator that performs
bit-by-bit ORing of its arguments.
It can be used as a logical operator in TRUE/FALSE
contexts.
Examples:
IF A=2 OR B=3 THEN 110
X% = B% OR 4 |
| PAGE |
A pseudo-variable controlling the
starting page of the current text area. With careful use,
several programs can be held in RAM memory without the
need for saving them.
Examples:
PAGE=&1900
PAGE=PAGE+&100 |
| PI |
A pseudo-variable with the value
3.14159265. |
| PLOT |
A multi-purpose graphics
statement. The first argument selects the function, and
the second and third arguments are x and y co-ordinates
for that function. The lower seven bits of the first
argument have the following meanings:
Bit Value Function0,1 00 No
change in memory while plotting (e.g. MOVE)
01 Plot in graphics foreground colour
10 Plot inverting colour
11 Plot in graphics background colour
2 0 Relative plot co-ordinates
1 Absolute plot co-ordinates
3-5 0 Must be 0
6 0 Line (continuous, with both endpoints)
1 Point
The maximum x and y co-ordinates are 1280 and 1024
respectively in all modes.
Example:
PLOT&45,X,Y (plots a point in the graphics foreground
colour at X,Y)
|
| POINT |
Not implemented. |
| POS |
Not implemented. |
| PRINT |
A statement that prints numbers,
characters and strings on the display. PRINT is
followed by a list of variables and constants to be
printed, with special items to control the format and
position of printing. The width of the print field, and
the number of figures and decimal places printed for
numbers, are controlled by the variable @%. The four
bytes of the value have the following functions:
| Byte |
Function |
| 0 |
print field width |
| 1 |
Maximum total number of
digits printed |
| 2 |
Numeric format:0 General
format
1 Exponent format
2 Fixed format |
| 3 |
STR$ format:
0 Ignore bytes 0-2
1 Use bytes 0-2 |
Byte 1 controls the number of
digits in a mode. If it is out of range then 9 is
assumed. In G mode it specifies the maximum number of
digits to be printed between 1 and 9. In E mode it
specifies the exact number of digits to be printed
between 1 and 9. In F mode it specifies the number of
digits to follow the decimal point, between 0 and 9.
E mode will print an optional -
sign, one digit, a decimal point, <Byte 1>-l
digits, an E and an exponent field in 3 characters,
padded with trailing spaces if necessary. The G mode will
print integral values as integers, numbers in the range
0.1 to 1 as 0.1 etc., numbers less than .1 or greater
than 1E<Byte 1> with an exponent of as few
characters as possible.
F mode will print numbers with
<Byte 1> digits after the decimal point unless the
total number would then have more than nine digits in
which case G mode is used.
Examples (all shown right justified):
| Number |
G2 |
G9 |
F2 |
E2 |
| .1 |
0.1 |
0.1 |
0.10 |
1.0E-l |
| .01 |
1E-2 |
1E-2 |
0.01 |
1.0E-2 |
| .001 |
1E-3 |
1E-3 |
0.00 |
1.0E-3 |
| .005 |
5E-3 |
5E-3 |
0.01 |
5.0E-3 |
| 1 |
1 |
1 |
1.00 |
1.0E0 |
| 10 |
10 |
10 |
10.00 |
1.0E1 |
| 100 |
1E2 |
100 |
100.00 |
1.0E2 |
The following characters have
special functions in PRINT:
| Character |
Function |
| ' |
Causes the next item to be
printed in the next field |
| ; |
Separates items without
the effect of , |
| . |
Suppresses the new line at
the end of the PRINT statement. |
| ~ |
Causes all numbers to be
printed in hex until ' or is reached |
| ’ |
Prints new line |
Examples Result
@%=&00090A
PRINT 1,2 1 2
PRINT 10,200 10 200
PRINT 10;200 10200
PRINT "Answer ";A Answer 42
PRINT "Answer "A Answer 42
PRINT "Answer ",A Answer 42
PRINT "Hi", "Hi" Hi Hi
PRINT "Hi ~; "Hi" HiHi
PRINTl'20 1
20
|
| PRINT# |
A statement which writes the
internal form of a value out to tape. The first argument
is the channel number. All numeric constants are written
as five bytes of binary real data. All strings are
written as the bytes in the string plus a carriage
return.
Example:
PRINT#E,A,B,C,D$,E$,F$ |
| PROC |
A reserved word used at the start
of all user-declared procedures. The arguments in the
body of the procedure are set to the values of the
arguments in the call.
Example:
INPUT "Number of
discs "F
PROCHANOI(F,l,2,3)
END
DEF PROCHANOI (A, B,C, D) IFA=0 ENDPROC
PROCHANOI (A-l,B,D,C)
PRINT "Move disk ";A" from pile
";B" to pile ";C
PROCHANOI (A-l,D,C,B)
ENDPROC |
| PTR# |
Not implemented. |
| RAD |
A function which converts degrees
to radians.
Example:
S%=SINRAD(90) |
| READ |
A statement which will set
variables to values read from the DATA
statements in the program. Strings may be enclosed in
double quotes unless they have leading spaces or contain
commas. |
| REM |
A statement that causes the rest
of the line to be ignored, allowing comments in the
program. |
| RENUMBER |
A command which will renumber the
lines and correct the cross references inside a program
accordingly. Options are as for AUTO. RENUMBER produces messages when a cross reference
fails. |
| REPEAT |
A statement which is the starting
point of a REPEAT ...
UNTIL loop. The statements
inside the loop are executed and repeated until the
expression after UNTIL is true. A single REPEAT may
have more than one UNTIL. These loops may be nested up to a maximum
depth of 20.
Example:
REPEAT A%=A%+RND(3)-l:
UNTIL A%>B% |
| REPORT |
A statement which prints out a
newline followed by the last-made error string. |
| RESTORE |
A statement that can be used at
any time in a program to set the place where DATA comes
from. The optional parameter for RESTORE can
specify a calculated line number.
Examples:
RESTORE
RESTORE 100
RESTORE (l0*A+20) |
| RETURN |
A statement causing execution to
return to the statement after the most recently executed GOSUB
statement. |
| RIGHT$ |
A string function which returns
the right n characters of the string. If there are
insufficient characters in the string then all are
returned.
Examples:
RIGHT$(A$,2)
RIGHT$(LEFT$(A$,3)12) |
| RND |
A function with optional parameter
that provides random numbers. RND(l)
returns a real number in the range 0.0 to .99999999. RND returns
a random integer 0 -&FFFFFFFF. RND(n)
returns an integer in the range 1 to n. If n is negative
the pseudo-random sequence generator is set to a number
based on n and n is returned. If n is 0 the last RND(1)
random number is returned. The argument to RND must
always be bracketed and there must be no spaces between RND and the
left bracket. |
| RUN |
A statement that runs the program
in the current PAGE.
All variables except @% to Z% are CLEARed. |
| SAVE |
A statement which saves the
current program area to a file.
Example:
SAVE "PRIMES" |
| SGN |
A function returning -l for
negative argument, 0 for 0 argument and +1 for positive
argument. |
| SIN |
A function giving the sine of its
radian argument. |
| SOUND |
A statement that produces a sound
from the ATOM's internal loudspeaker. Four arguments are
required: the first two are ignored, the third controls
the period of the tone, and the fourth sets the duration
in 10 ms units.
Example:
SOUND 0,0,300,100 |
| SPC |
A function which outputs n MOD 256
spaces where n is the argument. It can only be used in PRINT or INPUT. |
| SQR |
A function returning the square
root of its argument. |
| STEP |
Part of the FOR
statement, this optional section specifies step sizes
other than 1. |
| STOP |
Syntactically identical to END, STOP
also prints a message to the effect that the program has
stopped. |
| STR$ |
A string function which returns
the string form of the numeric argument as it would have
been printed. If the most-significant byte of @% is 1, STR$ uses
the current @% description for printing numbers, and if
zero (the initial value) the G9 format (see PRINT) is
used. |
| STR$~ |
A string function that returns the
string form of the numeric argument as it would have been
printed in hex. |
| STRING$ |
A function returning n
concatenations of a string, where n is the argument.
Example:
STRING$ (10,
"*--*") |
| TAB |
A function that changes the
position of printing, only available in PRINT or INPUT. TAB(X) will
attempt to make COUNT equal to X by printing a newline if required plus some
spaces. TAB(X,Y) will perform a cursor move on the screen to
character cell X,Y if possible. The leftmost column is column
0. |
| TAN |
A function returning the tangent
of its radian argument. |
| THEN |
The part of the IF statement
that precedes the statements to be executed if the IF condition
is TRUE. It may be replaced by : or a
space. |
| TIME |
A pseudo-variable which reads and
sets the lower four bytes of the computational real-time
clock. |
| TO |
The part of the FOR
statement that precedes the loop limit. |
| TOP |
A pseudo-variable which returns
the value of the first free location after the end of the
current text. |
| TRACE |
A statement that displays line
numbers as they are executed for debugging purposes. TRACE ON
causes the interpreter to print executed line numbers
when it encounters them. TRACE
X sets a limit on the size of
line numbers which may be printed out:
only those less than X will appear. Thus a careful user
with all subroutines at the end of the main program can
stop traced output of subroutine calls. TRACE OFF
turns TRACE off. Note that the interpreter does not
execute line numbers very often:
Program TRACE output
10 FORZ = O TO 100
20 Q=Q*Z:NEXT [ 10] f 20] [ 30]
30 END
But things would be different were NEXT on line
25. Then TRACE output would be:
[ 10] [ 20] [ 25] [ 25] [
25]
[ 25] [ 25] [ 25] [ 25] [ 25] …
[ 30] |
| TRUE |
A pseudo-variable having the value
-1. |
| UNTIL |
A part of the REPEAT ... UNTIL loop. The statements inside the loop are
executed until the expression following UNTIL yields
TRUE. |
| USR |
A function allowing machine code
to return a value directly for applications which do not
require the facilities of CALL.
USR calls the machine-code
subroutine whose address is it's argument, with the
processor’s A, X and Y registers and the C carry flag
initialised as in CALL, and returns a 32 bit integer composed of PYXA (msb to
lsb). |
| VAL |
A function which converts a
character string representing a number into numeric form.
If the argument does not represent a unary signed decimal
constant, VAL returns 0. |
| VDU |
A statement which takes a list of
numeric arguments and sends them to OSWRCH. The
arguments are normally separated by commas, whereupon the
least-significant byte of each is sent, but a semicolon
will cause the two least-significant bytes to be sent.
The bytes sent DO NOT contribute to the value of COUNT.
Examples:
VDU28,0,31,32,0:REM
define window
VDU27,0;0;1280;1024; |
| VPOS |
Not implemented. |
| WIDTH |
A statement controlling the
overall screen width for printing. The initial value is WIDTH 0 when
the interpreter will not attempt to control the overall
field width. WIDTH n will cause the interpreter to force a
newline after n MOD 256 characters have been printed. |