Changes

Jump to: navigation, search

Locomotive BASIC

2,881 bytes added, 20:58, 25 November 2022
/* CHR$ () */
==== <code>LOAD ‹file name›[,‹address›] </code>====
: [With this directive you may load any file in memory Basic files (extension .BAS) are loaded in Basic memory, you cannot choose loading address Binary files are loaded to the default address location stored in the AMSDOS header but you may force loading address (&C000 for a screen) TAPE convention: When loading tape files, the basic display a message every block which may cause trouble.Message output may be disabled by using prefix "!" before the filename.] It's also possible to load the next file disregarding his name using only "!" => <code>LOAD "!"</code>
==== <code>LOCATE[#‹stream expression›][,] x,y</code> ====
</pre>
:'''P:''' the period number can be a figure between 0 and 4095 (2^12-1... 12 means that we have 12 tones (inclusive half-tones) in nine octaves on the CPC in sum and their distance between is the twelves square root of two), where 8 octaves are available. E.g. Octave 0 starts on middle C with number 478.
: To calculate the period you can use following formula: '''period=1,000,000/(16*frequency)''' or in short '''period=(6562,000500/frequency)'''
: (e.g. the note "A" with the frequency 440 Hz has the period 142 on the CPC)
</pre>
==== <code>SPEED INK <n1,n2> </code> ====: ...in conjunction with the SPEED INK command SPEED defines the frequency of colour changes if a colour change was defined. The duration is calculated by n1=... or n2 =duration/50 seconds. ==== <code>SPEED KEY <start,repeat> </code> ====: SPEED KEY command defines the delay after which a key repeat (for keys that do repeat). The first parameter is the delay before the first repeat and the second parameter is the delay between further repeats. Delay is in 1/50th of seconds. :When using it with low values, it is common to associate a key to reset the default speed of 30,2.:For example to associate the key 0 from the numpad:<pre>KEY 0,"SPEED KEY 30,2"+CHR$(13)</pre> ==== <code>SPEED WRITE <n> </code> ====: SPEED WRITE defines the speed at which data is to be saved or written to a cassette unit. n=1 means 2000 baud, n=0 (default) means 1000 baud. When reading from the tape, the correct speed is automatically selected.
==== <code>SQ (channel)</code> ====
: Beware: it only works here with BIT/number conditions one figure smaller than 1, 3, 7, 15, 31, 63 and 127
==== <code>MOD</code> ====
: ['''MOD''' returns a (rounded) rest (Modulos) after dividen has been devided by the devisor...]::'''Example:'''<pre>32767 mod 256255</pre>: Note: only works with numbers in the range -32768 and 32767 (&8000 < 0 < &7FFF)
==== <code>NOT</code> ====
| 1 | &01 | SOH | 0-255 | PRINTS CHARACTER TO SCREEN |
| 2 | &02 | STX | NONE | TURNS TEXT CURSOR OFF |
| 3 | &03 | ETX | NONE | TURNS TEXT CURSOR ON IN IMMEDIATE || | | | | MODE |
| 4 | &04 | EOT | 0-2 | SET SCREEN MODE |
| 5 | &05 | ENQ | 0-255 | PRINT CHARACTER AT GRAPHICS CURS. |
| 17 | 145 (128+17) | File already exists. |
| 18 | 146 (128+18) | File does not exists. |
| 19 | 147 (128+19) | Direcotry Directory is full. |
| 20 | 148 (128+20) | Disc is full. |
| 21 | 149 (128+21) | Disc changed while file were open. |
run
</pre>
==== <code><big>VAL(se<string expression>)</big></code> ====: ''BASIC 1.0 & 1.1'': '''FUNCTION''': Returns the numeric VALue, (including any negative sign and decimal point) of the first character(s) in the specified <string expression>. :If the first character is not a number, then 0 is returned. If the first character is a negative sign or decimal point followed by non-numeric characters, a 'Type mismatch' error (13) will be reported.
:Returns the numeric value (including signs) of first numeric character(s) in se. Returns 0 if se starts with a non-number. '''Associated keywords''': STR$ :'''1. Example''':<pre>PRINT VAL("-12.34x"),VAL("A-12") - prints -12.34 0
</pre>
:'''Exception''': if <se> starts with "&amp;" + character (and it's between "A" and "F") the whole character will be handled like a hexadezimal numeric character (...often used in DATA Loaders). The returning numeric value is a &nbsp;signed&nbsp;integer (16-Bit Word). : '''2. Example''':<pre>PRINT&nbsp;VAL("&amp;A") - returns a 10
PRINT&nbsp;VAL("&amp;7FFF") - returns a 32767
PRINT&nbsp;VAL("&amp;8000") - returns a -32768</pre>: '''3. Example''':<pre>10 CLS: PRINT "I know my times tables!"20 PRINT:PRINT "Press a key (1 to 9)"30 a$=INKEY$:IF a$="" THEN 3040 n=VAL(a$):if n<1 or n>9 then 3050 FOR x=1 to 1260 PRINT n;"X";x;"=";n*x70 NEXT:GOTO 20run</pre>==== <code><big>VPOS (#<stream expression>)</big></code> ====: ''BASIC 1.0 & 1.1'': '''FUNCTION''': Reports the current vertical POSition of the text cursor relative to the top of the text window. The <stream expression> MUST be specified, and does NOT default to #0.
==== <code>VPOS (#st)</code> ====: Reports the current row (line) position of the text cursor relative to the top of the text windows of the specified stream.'''Associated keywords''': POS, WINDOW
: '''Example''':<pre>10 MODE 1:BORDER 0:LOCATE 8,220 PRINT "use cursor up/down keys"30 WINDOW 39,39,1,25:CURSOR 1,140 LOCATE 1,350 IF INKEY(0)<>-1 THEN PRINT CHR$(11);60 IF INKEY(2)<>-1 THEN PRINT CHR$(10);70 LOCATE #1,3,2480 PRINT #1,"text cursor ";90 PRINT #1,"vertical position =";100 PRINT #1,VPOS(#0):GOTO 50run</pre>==== <code><big>XPOS</big></code> ====: Returns ''BASIC 1.0 & 1.1'': '''FUNCTION''': Reports the current horizontal (xX) position POSition of the graphics cursor.
: '''Associated keywords''': MOVE, MOVER, ORIGIN, YPOS : '''Example''':<pre>10 MODE 1:DRAW 320,20020 PRINT "graphics cursor X position = ";30 PRINT XPOS</pre>==== <code><big>YPOS</big></code> ====: Returns ''BASIC 1.0 & 1.1'': '''FUNCTION''': Reports the current vertical (yY) position POSition of the graphics graphic cursor. : '''Associated keywords''': MOVE, MOVER, ORIGIN, XPOS : '''Example''':<pre>10 MODE 1:DRAW 320,20020 PRINT "graphics cursor Y position = ";30 PRINT YPOS</pre>
== Other Basic Dialects available for the CPC ==
912
edits