C-PS/8 FOCAL, 1971
 1.05 C FUNCT1.RE
 1.10 L C FOCAL.TM
 1.20 I (FITR(/2)-/2)1.8;S Z1=1.98;G 2.1
 1.50 I (FITR(/2)-/2)1.7;D 13;D 6;D 5
 1.55 I (FITR(/2)-/2),1.7;D 5.3;D 5.4;D 5.55
 1.70 S Z1=1.98
 1.75 T "REENTER PS/8 FOCAL AND RETAIN TRIG FUNCTIONS."!
 1.80 D 1.7;D 2;D 3;D 4;D 7;D 9;D 11;D 12;D 14;G 15.1
 1.98 T %6.04
 2.10 T !!!!!!"***** FUNCTIONS:"!!!!
 2.20 T "FOR MOST FUNCTIONS, A SAMPLE LINE IS SHOWN AND THEN EXECUTED:"!
 3.10 T "FABS( )  ABSOLUTE VALUE"!
 3.20 T %6.04,"EXAMPLE (WRITTEN THEN EXECUTED):"!
 3.30 W 3.4
 3.40 TYPE FABS(-3),FABS(2),!!!!
 4.10 T "FADC( )  ANALOG TO DIGITAL INPUT FUNCTION"!;D Z1;W 4.22
 4.20 T !!!;G 4.9
 4.22 SET X=FADC( );TYPE !!!!
 4.90 C
 5.10 T "FATN( )  ARCTANGENT    ARGUMENT RANGE:  0<A<10^6"!;D Z1;W 5.25
 5.16 T "PRECISION DOES NOT EXCEED 6 DIGITS AND DROPS FOR NEAR-ZERO ARGUMENTS"!
 5.25 TYPE FATN(1),!!!!;COM:  OUTPUTS RADIAN ANGLE WHOSE TANGENT = 1.00
 5.30 T "-------  TANGENT   	FTAN( )	 IS NOT AVAILABLE"!
 5.40 T "TANGENT IS COMPUTED AS THE QUOTIENT (SINE/COSINE)"!;W 5.55
 5.55 TYPE FSIN(1)/FCOS(1),!!!!;COMMENT:  OUTPUTS TANGENT OF 1 RADIAN
 6.10 T "FCOS( )  COSINE"!;D Z1;W 6.27
 6.27 TYPE FCOS(1),FCOS(3/2),!!!!; COM: OUTPUTS COSINES OF 1 & 1.5 RADIANS
 7.10 T "FDIS( )  DISPLAY FUNCTION FOR DEC TYPE 34D DISPLAY"!
 7.15 T "EXAMPLE:"!;W 7.2
 7.17 G 7.3
 7.20 SET DU=FDIS(X,Y)
 7.30 T "(PLOTS A POINT AT POSITION (X,Y) ON DISPLAY)"!
 7.40 T "(	DU	 IS DUMMY VARIABLE)"!!
 7.50 T "DISPLAY AND JOYSTICK FUNCTIONS FOR PS/8 FOCAL ARE AVAILABLE FOR THE"!
 7.60 T "TEKTRONIX T-4002 GRAPHIC COMPUTER TERMINAL"!!!!
 8.10 T "FEXP( )  EXPONENTIAL"!;D Z1;W 8.24
 8.24 TYPE FEXP(1),FEXP(2.17),!!!!; COM: NATURAL BASE TO THE POWER (X)
 9.10 T "FITR( )  INTEGER"!;D 9.15;D 9.16;D 9.17;D Z1;W 9.18
 9.12 G 9.18
 9.15 T "SERIOUS ROUNDING ERRORS OCCUR FOR NUMBERS OF MORE THAN 5 DIGITS."!
 9.16 T "THE PROBLEM MAY BE HANDLED BY ADDING EMPIRACAL CONSTANTS TO THE"!
 9.17 T "ARGUMENT."!
 9.18 TYPE FITR(3/2),FITR(23.719),FITR(-2.99),!!!!
10.10 T "FLOG( )  NATURAL LOGARITHM"!;D Z1;W 10.14
10.14 TYPE FLOG(1),FLOG(4.237),FLOG(10),!!!!
11.10 T "FRAN( )  RANDOM NUMBER"!;D Z1;W 11.22
11.22 TYPE FRAN( ),FRAN( ),FRAN( ),FRAN( ),FRAN( ),!
11.30 T "THE PSEUDO-RANDOM NUMBERS PRODUCED ARE PART OF A VERY LONG AND WELL"!
11.40 T "DISTRIBUTED BUT DETERMINISTIC SERIES.  YOU WILL USUALLY OBSERVE AN "!
11.50 T "ENTIRELY DIFFERENT SERIES EACH TIME FOCAL IS INITIALIZED.  HOWEVER,"!
11.60 T "FRAN( ) DOES NOT GENERATE TRULY RANDOM NUMBERS."!!!!
12.10 T "FSGN( )  SIGN"!;D Z1;W 12.34
12.34 T %1.0 FSGN(2.78),"  ",FSGN(-299),"  ",FSGN(0),"  ",FSGN(-1),!!!!
13.10 T "FSIN( )  SINE OF AN ANGLE GIVEN IN RADIANS"!;D Z1;W 13.52
13.52 TYPE FSIN(1),FSIN(0),FSIN(37-2.22),!!!!
14.10 T "FSQT( )  SQUARE ROOT OF A POSITIVE NUMBER"!;D Z1;W 14.4
14.40 TYPE FSQT(4),FSQT(391),FSQT(.0038953),!!!!
15.10 L R FUNCT2.RE 9.1