t_a

;currently does nothing (should make a 'beep noise')
;inputs: none
;outputs: none
beep:
  lda $900e
  ora #15
  sta $900e  ;set volume

  ;turn on osc. 3
  lda #$FF
  sta $900c

; pause for qtr second
  jsr timer_read
  stx beep_timer
  inc beep_timer
  inc beep_timer  
:  
  jsr timer_read
  cpx beep_timer
  bne :-

  ;turn off osc. 3
  lda #$00
  sta $900c

  rts

  
;print a single char in inverse text:
print_a_inverse:
  pha
  lda #18 ;inverse mode on 
  jsr print