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Elite on the BBC Micro

Keyboard: PAS1 (6502SP version)

Name: PAS1 [View in context] Type: Subroutine [Compare versions] Category: Keyboard Summary: Display a rotating ship at space coordinates (0, 112, 256) and scan the keyboard
Returns: X If a key is being pressed, X contains the internal key number, otherwise it contains 0 A Contains the same as X
.PAS1 LDA #112 \ Set y_lo = 112 STA INWK+3 LDA #0 \ Set x_lo = 0 STA INWK STA INWK+6 \ Set z_lo = 0 LDA #2 \ Set z_hi = 1, so (z_hi z_lo) = 256 STA INWK+7 JSR LL9 \ Draw the ship on screen JSR MVEIT \ Call MVEIT to move and rotate the ship in space JMP RDKEY \ Scan the keyboard for a key press and return the \ internal key number in X (or 0 for no key press), \ returning from the subroutine using a tail call