.mmregs
  .def cos_generate,begin
  .def d_cos_delay1,d_cos_delay2,d_theta,d_cosx
  
d_cos_delay1  .usect "cos_vars",1
d_cos_delay2  .usect "cos_vars",1
d_theta       .usect "cos_vars",1
d_cosx        .usect "cos_vars",1


k_cos_delay1  .set  064d8h  ;COS(10)*0.8
k_cos_delay2  .set  06602h  ;COS(5)*0.8
k_cos_theta   .set  07f83h  ;COS(5)
k_2           .set  2h
k_256         .set  256
COSDATA       .usect "cos_data",256

  .text
begin:
  SSBX FRCT
  ST   COSDATA,ar5   ;;;;;;;;;;;;;;;;;;;;;;;;;;
  NOP
  STM  #600H,SP
  LD  #d_cos_delay1,DP  
  STM  #d_cos_delay1,ar3  ;;;d_cos_delay=ar3
  
  STM  #d_theta,ar4
  RPTZ A,#3H
  STL  A,*ar3+
  
  STM  #1,ar0
  STM  #d_cosx,ar2  ;;;d_cosx=ar2
  STM  #k_2,BK
;  STM  #k_256-1,BRC ;;;;;;;;;;;;
  
  STM  #d_cos_delay1,ar3
  ST   #k_cos_delay1,*ar3+
  ST   #k_cos_delay2,*ar3
  STM  #d_cos_delay1,ar3
  ST   #k_cos_theta,d_cosx
  
cos_generate:
;  RPTB  end_of_cos-1;;;;;;;;;
  MPY   *ar2,*ar3+0%,A
  SUB   *ar3,15,A
  SFTA  A,1,A
  STH  A,*ar3
  SFTA A,-8,B
  AND #00FFh,16,B
  BC  NEG_8,ALT
;  OR  #0FF00h,16,B
NEG_8:
  XOR #0FF80h,16,B
  STH  B,*ar4
  RPT  #100h
  NOP
  PORTW *ar4,0bfffh

  
;  MVDD *ar4,*ar5+
  NOP
  NOP

  B    cos_generate
;end_of_cos:;;;;;;;;;;;

LOOP
    B   LOOP
  .end