Translating Assembly Language to English (EASy68K)

Question

Was given the following code in class and am supposed describe what each line means in comments to the right. Is this correct?

       MOVE.B  #20,D0     //Move 20 into D0
       MOVEA.L #$1000,A0  //Move the contents of address 1000 into A0 
       CLR.B   D1         //Set D1 to 0
Again  CMP.B   (A0)+,D2   //Compare A0 to D2, then increment A0 by 1
       BNE     NEXT       //If A0 and D2 are not equal, go to NEXT, otherwise continue
       ADD.B   #1,D1      //Add 1 to D1
NEXT   SUB.B   #1,D0      //Subtract 1 from D0
       BNE     Again      //Branch to AGAIN if contents of A0 is not equal to D2

Answer 1

No, it's not correct. At the very least, this:

Again  CMP.B   (A0)+,D2   //Compare A0 to D2, then increment A0 by 1

...is not comparing the content of A0 to anything. It's comparing a byte at the address contained in A0 to a byte in D2 (then incrementing A0 to point to the next address).

If I'm not mistaken, in these lines:

NEXT   SUB.B   #1,D0      //Subtract 1 from D0
       BNE     Again      //Branch to AGAIN if contents of A0 is not equal to D2

The zero-flag should be set/cleared based on the result of the immediately preceding sub.b, so it's continuing for 0x20 iterations (because D0 was loaded with 0x20 in the first line).