Routines
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27332: Action: Beep
Used by the routine at WaitForKey.
Turns A and B into a duration and a pitch and hands them to the ROM beeper. The key click uses A equal to 30. Action 0 of the bytecode jumps straight to the same ROM routine, whose address is the operand of the jump below.
Beep 27332 AND A Duration A is the low byte of HL, and B is the pitch.
27333 LD L,A
27334 LD A,B
27335 LD D,0 The high byte of the duration, and D, start at zero.
27337 LD H,D
27338 ADD A,A Shift the pitch two places, keeping the overflow in D.
27339 ADD A,A
27340 RL D
27342 LD E,A Save that pitch.
27343 PUSH DE
27344 CALL 12457 Call HL=HL*DE to scale the duration by the pitch.
27347 POP DE Restore the pitch for the beeper from the stack.
27348 JP 949 Jump to BEEPER.
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