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⌂ ∞ Elite on the BBC Micro and NES

Keyboard: scan_10in

[Elite-A, I/O processor]

       Name: scan_10in                                               [Show more]
       Type: Subroutine
   Category: Keyboard
    Summary: Implement the scan_10in command (scan the keyboard)

    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * tube_table calls scan_10in




 This routine is run when the parasite sends a scan_10in command. It scans the
 keyboard for a key press and returns the internal key number of the key being
 to the parasite (or it returns 0 if no keys are being pressed).



.scan_10in

 JSR RDKEY              \ Scan the keyboard for a key press and return the
                        \ internal key number in X (or 0 for no key press)

 JMP tube_put           \ Send A back to the parasite and return from the
                        \ subroutine using a tail call