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TITLE Sine of an Angle (EX59.ASM) PAGE ,132 DATA SEGMENT PARA 'DATA' SINES DW 0,175,349,523,698,872 ;0-5 DW 1045,1219,1392,1564,1736 ;6-10 DW 1908,2079,2250,2419,2588 ;11-15 DW 2756,2924,3090,3256,3420 ;16-20 DW 3584,3746,3907,4067,4226 ;21-25 DW 4384,4540,4695,4848,5000 ;26-30 DW 5150,5299,5446,5592,5736 ;31-35 DW 5878,6018,6157,6293,6428 ;36-40 DW 6561,6691,6820,6947,7071 ;41-45 DW 7193,7313,7431,7547,7660 ;46-50 DW 7771,7880,7986,8090,8191 ;51-55 DW 8290,8387,8480,8572,8660 ;56-60 DW 8746,8829,8910,8988,9063 ;61-65 DW 9135,9205,9272,9336,9397 ;66-70 DW 9455,9511,9563,9613,9659 ;71-75 DW 9703,9744,9781,9816,9848 ;76-80 DW 9877,9903,9926,9945,9962 ;81-85 DW 9976,9986,9994,9998,10000 ;86-90 DATA ENDS OUR_CODE SEGMENT PARA 'CODE' PUBLIC FIND_SINE FIND_SINE PROC FAR ASSUME CS:OUR_CODE,DS:DATA PUSH DS ;Save the caller's registers PUSH AX PUSH CX ; ; Initialize the data segment address. ; MOV BX,DATA MOV DS,BX ; ; This is the look-up procedure. ; SUB CX,CX ;Initialize sign to 0 CMP AX,181 ;Angle < 181 degrees? JB SIN_POS ; Yes. Continue with sign = 0 MOV CX,8000H ; No. Set sign = 1 SUB AX,180 ; and subtract 180 from angle SIN_POS: CMP AX,91 ;Angle < 91 degrees? JB GET_SIN ; Yes. Go look up sine NEG AX ; No. Subtract angle from 180 ADD AX,180 GET_SIN: MOV BX,AX ;Make angle a word index SHL BX,1 MOV BX,SINES[BX] ; and look up the sine value OR BX,CX ;Combine sine with sign bit POP CX POP AX POP DS RET ; and exit FIND_SINE ENDP OUR_CODE ENDS END FIND_SINE

SP>> Hаpод, помогите плз, как сделать ф-цию Cинyс на асме??? AK> 1. Мат. Сопpоцессоp. 387 > AK> 2. Составить вою таблицу значений и использовать ее === Cut === Here's some explanation about the sinus table generator in the ACE BBS advert. The method used is a recursive sinus sythesis. It's possible to compute all sinus values with only the two previous ones and the value of cos(2у/N) , where n is the number of values for one period. It's as follow: Sin(K)=2.Cos(2у/N).Sin(K-1)-Sin(K-2) or Cos(K)=2.Cos(2у/N).Cos(K-1)-Cos(K-2) The last one is easiest to use , because the two first values of the cos table are 1 & cos(2у/n) and with this two values you are able to build all the following... Some simple code: the cos table has 1024 values & ranges from -2^24 to 2^24 build_table: lea DI,cos_table mov CX,1022 mov EBX,cos_table[4] mov EAX,EBX @@calc: imul EBX shrd EAX,EDX,23 sub EAX,[DI-8] stosd loop @@calc cos_table dd 16777216 ; 2^24 dd 16776900 ; 2 ^24*cos(2у/1024) dd 1022 dup (?) Enjoy KarL/NoooN === Cut === С бестовыми регардами , Kostya Volkov aka Reminder // [WW] [DVC] --- * Origin: chaos a.d. (2:4631/17)