OpenEuphoria

Re: keyboard help

• Posted by David Cuny <dcuny at LANSET.COM> May 10, 1999
• 636 views

"IllusionEye" wrote:

> I would like to know how to put a sequence of keys into the keyboard
buffer (memory).

It's been a long time since I've worked with this, so I'm a bit fuzzy on
this...

The keyboard buffer is a circular queue. The addresses are:

    KEY_BUFFER = 1054
    FIRST_INDEX = 1050
    LAST_INDEX = 1052

KEY_BUFFER is the address of the circular buffer.
FIRST_INDEX is the index (offset) to the first key in the buffer
LAST_INDEX is the index (offset) to the last key in the buffer

When FIRST_INDEX = LAST_INDEX, the buffer is empty. You can zap the buffer
by setting them to the same value:

    poke( FIRST_INDEX, peek( LAST_INDEX ) )

I *think* the buffer can hold up to 16 characters. Each character is stored
as two bytes - the scan key code and the key code. Notice the "- 29" and "-
30"; I hacked at the values until the worked.

    scanCode = peek( KEY_BUFFER + peek( FIRST_INDEX ) - 29 )
    keyCode = peek( KEY_BUFFER + peek( FIRST_INDEX ) - 30 )

So the buffer is (I think) 32 bytes long in total. Since it's circular,
don't forget to wrap your characters. Obviously, when the LAST_INDEX is
advanced past the end of the buffer, it needs to wrap around to the
beginning again. If the LAST_INDEX is advanced onto the FIRST_INDEX, the
buffer will be overwritten.

Ick.

-- David Cuny