program Ballistic
/******************************************************************************
 * Description:    Simulates the height of a projectile, starting at a height of
 *                 mem[0C] with an initial velocity of mem[0B], until the 
 *                 projectile no longer has a positive height.  The acceleration 
 *                 due to gravity is given as mem[0A].
 * Input:          a0, v0, and y0 in mem[0A], mem[0B], and mem[0C], respectively
 * Output:         A plot of y over time starting at mem[20] 
 ******************************************************************************/

0A: FFF6   constant 0xFFF6               a0 = -10; // m/s^2
0B: 0012   constant 0x0012               v0 =  18; // m/s
0C: 0015   constant 0x0015               y0 =  21; // m

10: 7101   R[1] <- 0001                  // We use R[1] as the constant 1
11: 7A20   R[A] <- 0020                  yPlot = allocateArray();
12: 7300   R[3] <- 0000                  t = 0;
13: 820A   R[2] <- M[0A]                 a = a0;
//                                       // A good estimate of delta is f'(.5)
//                                       // which is approximately v0 + a/2
14: 840B   R[4] <- M[0B]                 delta = v0;
15: 6F21   R[F] <- R[2] >> R[1]          temp = a >> 1;   // that's a/2
16: 144F   R[4] <- R[4] + R[F]           delta += temp;
17: 850C   R[5] <- M[0C]                 y = y0
18: B50A   M[R[A]] <- R[5]               yPlot[0] = y0

19: 1554   R[5] <- R[5] + R[4]           do { y += delta
1A: 1442   R[4] <- R[4] + R[2]                delta += a;
1B: 1331   R[3] <- R[3] + R[1]                t++;
1C: 17A3   R[7] <- R[A] + R[3]                ptr = &(yPlot[t]);
1D: B507   M[R[7]] <- R[5]                  *ptr = f(i);
1E: D519   if (R[5] > 0) goto 19         } while (y > 0);

1F: 0000   halt