ABS (numeric)

- Computes absolute value

  Example:
  
  100 V = ABS(5)


    
ASC (str)
 
- Returns ASCII code of first charactr of specifed string.

  Example:
  
  100 A = ASC( T$ )   

    


ATN (numeric) 

- Returns arctangent in radians.

  Example

  100 Y = ATN(X/3) 



CHR$(n)

- used to find character from ASCII code.

  Below is a partial table printed on the Tandy (32 being a space):
  

  CHR$ can also be used to print graphic characters in default 
  text/semigraphics mode.  This is also set with the command PMODE 0,[X] .
  
  

  Starting at 128 are the Graphic Blocks

  Colors for Coco 2 with Extended Color BASIC 1.x
  
  128 - 143 is Green and Black blocks     143 = Green solid block
  144 - 159 is Yellow and Black blocks    159 = Yellow solid block
  160 - 175 is Blue and Black blocks      175 = Blue solid block
  176 - 191 is Red and Black blocks       191 = Red solid Block
  192 - 207 is Buff and Black             207 = Buff (white-ish) solid block
  208 - 223 is Cyan and Black             223 = Cyan solid block
  224 - 239 is Magenta and Black          239 = Magenta solid Block
  240 - 255 is Orange and Black           255 = Orage solid block
  
                                              
  
  
  


CLS c

– Clears text screen, optionally filling it with a color (0-8).

  CLS c Clears display to specified color c. If color is not specified, green 
  is used.

  0-Black
  1-Green 
  2-Yellow
  3-Blue
  4-Red
  5-Buff (white-ish)
  6-Cyan
  7-Magenta
  8-Orange

  Example:
  
  CLS 7
  
  Note:  This is the clear screen command for text mode.  For graphics mode 
         use PCLS

  

COLOR (forground,background) 

- Sets forground and background color.

  Example:
  
  COLOR 1, 3
  
  

CONT 

- Continues program execution after pressing or (break) useing STOP statement



DRAW "string"

- Draws a line beginning at specified starting point of specified length of 
  specified color. Will also draw to scale, draw blank lines, draw non-updated 
  lines, and execute substrings. If starting point in not specified, the last 
  DRAW position or default of (128,96) is used. 

  Example1:
  
  40 DRAW "U20R20D20L20"
  
  the example will draw a box
  
  Example2:
  
  40 DRAW "BM100,100;S10;U25;BR25;ND25,XA$;"
  
  Movement Commands
  
  The DRAW command uses specific character codes to determine direction and 
  movement: 

  Un: Up
  Dn: Down
  Ln: Left
  Rn: Right
  En: Diagonal Up/Right
  Fn: Diagonal Down/Right
  Gn: Diagonal Down/Left
  Hn: Diagonal Up/Left
  "n" represents the number of pixels to move. 
  
  For example, DRAW "U10 R5" moves the cursor 10 pixels up and then 5 pixels 
  right. 

  Special Control Commands
  
  M x,y: Move to absolute coordinate (x,y) or relative (+x,+y) if a + or - sign 
         is used.

  B: Move without drawing (Blank). E.g., DRAW "BU10" moves up 10 pixels without 
     plotting them.

    Like with the U and other movement commands, B and M can be combined as for 
    example:
  
    DRAW "BM100,100"

  N: Move and draw, but return to the original position afterward (No-update).
  
    For example, drawing down for 25:
    
    DRAW "ND25"

  Cn: Set color (n = 0-3 for CoCo 1 and 2, or higher with CoCo 3 palettes).

  Sn: Set scale factor (n). Default is 4. Scale 1 is smallest, 255 is largest.

  An: Set angle (n = 0, 1, 2, 3). 0=0°, 1=90°, 2=180°, 3=270°. 
  



END

- Ends execution of BASIC code.



FOR and NEXT and optional STEP

- Create a stepped loop

  Example:
  
  10 FOR I = 1 TO 10
  20 PRINT I 
  30 NEXT I
  
  To print every other number use the STEP
  
  Example2:
  
  10 FOR I = 1 TO 10 STEP 2
  20 PRINT I
  30 NEXT I



GOSUB line-number

- Calls a subroutine beginning at specified line number.

  Example:
  
  GOSUB 500



GOTO line-number

- Jumps to a specified line number.

  Example:
  
  10 GOTO 300 
  


IF and THEN and optional ELSE

- check values for condtions 

  Example 1:
  
  10 IF A=5 THEN 30
  
  will jump to line 30 if the value of A is 5.
  
  
  Example 2:

  10 IF A>B THEN 100
  
  will jump to line 100 if the value of A is greater than the value of B
  
  
  Example 3:
  
  100 IF X=10 THEN PRINT "YES" ELSE PRINT "NO"

  


INPUT var

- Takes input from keyboard

  Example 1:
  
  10 INPUT A$
  
  This will read and store a string from the keyboard
  
  10 INPUT D
  
  This will read and store a number from the keyboard



MEM 

- Finds the amount of free memory.

  Example:
  
  PRINT MEM



MID$ (str,pos,length) 

- Returns a substring of another string starting at pos. If lenght is omitted, 
  the entire string right of position is returned.

  Example:
  
  100 F$ = MID$( A$, 3)
  
  Example2:
  
  PRINT MID$(A$, 3, 2) 



PCLS

- graphic clear screen


  see PMODE
  
  


PEEK

  looks at a memory address

  Example Command: 
  
  PRINT PEEK(116)*256 + PEEK(117) + 2 ; "BYTES"

    Result: Shows how much RAM the computer has, but a 64K machine will appear 
    to be a 32K machine (32768 Bytes) because Basic only uses the first 32K of 
    RAM in a 64K machine.

  Result: Returns maximum memory in System.



PLAY "string"

  PLAY "note"
  PlAY "length;note"
  PLAY "volume;note"

  MUSICAL NOTE/NUMBER
  Number  Note  
  1       C     
  2       C#/D  
  3       D     
  4       E-/D# 
  5       E/F   
  6       F/E#  
  7       F#/G  
  8       G     
  9       G#/A  
  10      A     
  11      A#/B  
  12      B     

  

  Note: PLAY does not recognize the notation B# or C-. 
  
  Play A note:
  PLAY "A"

  Add another note:
  PLAY "A;A#"
  
  Add pause

  PLAY "A;P2;A#"

  Change Volume

  PLAY "V5;A;P2; V10;A;P2; V30;A;P2"

  Change Note Length
  
  PLAY "L2;A;L4;A;A;L2;A;A"
  




PMODE number,number

- Set graphic mode

  The first number is the mode number, the second number is the start page.

  PMODE and POKE are used to change video graphic modes.

  CoCo 1 and CoCo 2 Motorola 6847 VIDEO DISPLAY GENERATOR (VDG) offers 
  Full Graphic Modes resolution in densities of:

  Mode      POKE  Resolution  TYPE  Colors  Screens  Byte  Detail                                  
  PMODE 4         high        RG6   2        2             256x192 (2 colors or 4 artifact colors*)
  PMODE 3         medium      CG6   4        2             128x192 (4 colors)                      
  PMODE 2         medium      RG3   2        4             128x192 (2 colors or 4 artifact colors*)
  PMODE 1         low         CG3   4        4             128x96  (4 colors)                      
            X                 SG24  9                      64x192  (9 colors)                      
            X     low         SG12  9                      64x96   (9 colors)                      
            X     low         SG6   9                2x3   64×48   (9 colors)                      
  PMODE 0         low         SG4   2/9      8       2x2   64x32   (9 colors grx and 2 colors text)
                                                                   (text is 32 cols x 16 lines )   

  * Artifact colors work on composite video displays and RF displays. They don't work with S-Video.
  With S-Video, there will only be 2 colors.

      

  
  
  

  Use the SCREEN command to choose the color palette of the mode.

  Example:
  
  10 PMODE 4,1:SCREEN 1,1  'Set graphics mode
  20 PCLS 0                'Clear screen

  NOTE: Something better than these 5 Microsoft defined modes (PMODE).

  PMODE 0 is the same as Semigraphics-4 mode or SG4

  There are three modes not defined with the PMODE command:

  - Semigraphics-6 mode or SG6  
  - Semigraphics-12 mode or SG12
  - Semigraphics-24 mode or SG24

  Like SG4, SG6, SG12 and SG24 can also use all colors available.

  Semigraphics-24 mode (SG24) is basically a 64x192 character screen with the 
  9 colors in a 4 on and 4 off pattern - giving the user a 64x192. 
  This mode is like crossing PMODE 0 and PMODE 4.
  
  
  Example image created in the SG24 mode.

  Semigraphics-24 (or SG24) is a "hybrid" display mode that combines text and 
  graphics modes to achieve a unique 9-color display that is much better than
  the PMODE 0 9-color display. 

  Key Technical Details

  Mechanism: It works by tricking the Motorola 6847 Video Display Generator (VDG). 
  By setting the Synchronous Address Multiplexer (SAM) to a high-resolution graphics 
  mode while leaving the VDG in an alphanumeric/semigraphics mode, the screen is 
  subdivided into smaller "slices".

  Resolution: It provides a 64×192 effective resolution. In this mode, each 8×12 
  pixel character box is split into six vertically stacked blocks, each 4×2 pixels 
  in size.

  Color Palette: It allows the use of all 9 available colors (green, yellow, blue, 
  red, buff, cyan, magenta, orange, and black) simultaneously on one screen.

  Memory Usage: A full Semigraphics-24 screen consumes 6,144 bytes of RAM.
 
  Example code to enable the SG24 mode:
  
  10 CLS
  20 POKE &HFF22,0 : REM RESET VDG TO SEMIGRAPHICS ZERO IS SG MODE
  30 POKE &HFFC3,1 : REM SET SAM TO GRAPHICS MODE (GM1) = 1
  40 POKE &HFFC5,1 : REM SET SAM TO GRAPHICS MODE (GM2) = 1
  50 POKE &HFFC0,0 : REM ENSURE SAM RESOLUTION BIT 0 IS LOW (GM0)
  55 REM is set for CG6 Mode while still in SG mode

  Example code to enable the SG12 mode

  10 CLS
  20 POKE &HFF22,0 : REM RESET VDG TO SEMIGRAPHICS ZERO IS SG MODE
  30 POKE &HFFC3,0 : REM SET SAM TO GRAPHIC MODE (GM1) = 0 
  40 POKE &HFFC5,0 : REM SET SAM TO GRAPHIC MODE (GM2) = 0
  50 POKE &HFFC7,0 : REM ENSURE VDG IS IN ALPHANUMERIC MODE
  
  -  
  Note on POKEs and what they are for (see table 1 above):
   POKE &HFF22,0    Resets the VDG to SEMIGRAPHICS - ZERO is SG Mode
   POKE &HFFC0,0    V0 clear
   POKE &HFFC1,0/1  V0 Set to 0 or 1
   POKE &HFFC2,0    V1 clear
   POKE &HFFC3,0/1  V1 Set to 0 or 1
   POKE &HFFC4,0    v2 clear
   POKE &HFFC5,0/1  V2 Set to 0 or 1

  


POKE (location, value) 

- Puts value (0-255) into specified memory location.

  Example:
  
  POKE 25,6:POKE 26,1:POKE 1536,0:NEW

  Makes maximum memory available for basic programs.
  Any basic program in memory is cleared. Not compatible with disk systems. 
  Does not allow the use of graphics.
  
  Example Command2: 
  
  POKE 280,PEEK(275)

  Result: Helps COCO Generate 'TRUE' Random Numbers.
  Remarks: Same as the Ext. Basic Statement   
  X = RND(-TIMER).
  



PRESET(number,number) 

- Reset a point to background color.

  Example:
  
  PRESET (5,6)



PRINT 

- Prints specified message or number to screen.

  Example:
  
  PRINT "HI THERE" 
  
  The print command can be substitued with the ?
  
  Example2:
  
  ? "Hi THERE"
  
  The PRINT command can concatenate with the ;
  
  Example 3:
  
  100 X=5
  110 PRINT "THE VALUE IS ";X
  
  Example 3 will print
  
  THE VALUE IS 5
  
  Example 4:
  
  100 PRINT "HELLO ";
  110 PRINT "THERE"
  
  Example 4 will print 
  
  HELLO THERE
  
  Using the @ with print will allow placement at a location
  
  Example 5:
  
  100 PRINT @5,"WELCOME!"
  
  Will print WELCOME at row 1 and column 5 on the screen.
  
  Example 6:
  
  100 PRINT USING "###",NUM
  
  Will format a number 3 places right justified.  Great for columns that need
  alocated space so not to alter text or graphics around the number.
  



REM

- Non executed comment or a remark usually for documenting purpose. 

  Example:
  
  100 REM THIS LINE DOES NOTHING



RETURN

- Used to return to the place of the GOSUB



RND

- Creates a random number

  Example:
  
  RND(0) 
  
  Returns a random floating-point number between 0 and 0.99999999999999.

  Example 2:
  
  10 X = RND(-TIMER) :REM Seed the generator
  20 FOR I = 1 TO 10
  30 PRINT RND(10); :REM Print 10 random numbers between 1-10
  40 NEXT I



SCREEN n1,n2

  n1 = is the screen
  n2 = is the color set
  
  Both depending on PMODE *see PMODE command
  
                 2-Color            4-Color
  SCREEN 1,0   Black/Green       Green/Yellow/Blue/Red
  SCREEN 1,1   Black/Buff        Buff/Cyan/Magenta/Orange


  

SGN (numeric) 
  
-  Returns sign of specified numeric expression



SIN (numeric) 

- Returns sine af angle gleen in radians



SOUND tone, duration

  tone can be 1 to 255
  duration can be 1 to 255


  Example:
  
  10 PRINT "TO MAKE ME CHANGE MY TONE"
  20 PRINT "TYPE IN A NUMBER FROM 1 TO 255"
  30 INPUT T
  40 SOUND T, 50
  50 GOTO 10

  The example will play the tone of the number entered between 1 and 255


  SOUND 1,2   = 1 is lowest octive 
  SOUND 39,2  = is Middle C 
  SOUND 120,2 = is C
  SOUND 255,2 = 255 is hight octive





STRINGS (length, code or string) 

- Returns a string of characters (of specified length) specified by ASCll code 
  or by the first character of the string.



SQR (numeric)

- Square root of a number

  Example:

  Y=SQR(5+2)