Learning to Program with the Cybiko Handheld Computer Using B2C

Chapter 16 : Miscellaneous

Beep

B2C includes a simple command for making sound.  It is different from the beep command in CyBasic2.  The Beep command causes the speaker to make a single tone.  Beep takes values from 1 (low-pitch) to 63 (high-pitch).  Beep 0 will result in silence.

Wait

There are 2 ways to create a delay in B2C.  One way is to write a For loop which does nothing:

for i=0 to 100
next i

This is not recommended.  It is sloppy coding and will be unpredictable in the event that Cybiko, Inc releases a newer, faster Cybiko.  The alternative is the Wait command.  The parameter is a number of tenths of seconds to wait.  So, to wait one second:

wait 10

Key

The Key command has two modes.  In the first, it acts like a variable. 

x = key

It returns the value of the last key pressed on the keypad.  This is very useful for writing interactive games because it does not stop the action like the Input statement does.  At the end of this chapter is a table of all the values the Key variable can return.  To use the table, find the key you want to check against and add the values in the corresponding row and column.  For example, the letter 'a' is 90+7=97.

The other format for the key command is as a function to check a single key:

x = key(#KEY_ENTER)

In this mode you specify the key you want to check and key() returns True or False.  Here is a listing of some of the constants you may use (note, these must be in uppercase)…

#KEY_A - #KEY_Z
#KEY_0 - #KEY_9
#KEY_UP
#KEY_DOWN
#KEY_LEFT
#KEY_RIGHT
#KEY_ENTER
#KEY_SPACE
#KEY_INS
#KEY_DEL

dim x as int    'horizontal component of the dot
dim y as int    'vertical component of the dot
dim z as int  'the key pressed
x=0    'initial x position of the dot
y=0    'initial y position of the dot
cls     'clear screen
point x,y  'show the dot
for i=0 to 1 step 0  'loop forever
z = key              'save off the key because it changes
  if z = 264 then    'left key
    ink 0
    point x,y
    ink 3
    x=x-1            'move left
    point x,y        'print new dot
  elseif z = 266 then' right key
    ink 0
    point x,y
    ink 3
    x=x+1            ' move right
    point x,y        ' print new dot
  end if
next 'end of forever loop