Assembly via Debug...

hello masters.
i have an exam including 4 questions and have to use debug only
i have searched here, Googled but i could fins just few examples about date, here also... but i could not use it via debug...
i have done first 2 questions but i have trouble with 3rd and 4th
1st >>> write the program which prints chars between 255 and 160 ASCII

2nd >>> imagine that you're using B&W monitor, Write Char "A" to the 01x01 coordinates.

3rd >>> write the program which reads 1 or more sectors from diskette directly

4th >>> how to write a program to learn and print computer date


answers....
1st >>>

Code:

0100 mov ah,2
0102 mov dl,FF (DL=255)
0104 int 21 (PRINT TO SCREEN)
0106 sub dl,1 (i could use dec dl,,, DL=DL-1)
0109 cmp dl,9F (DL=?159)
010C jne 0104 (IF DL<>159 THEN GOTO 0104)
010E int 20 (ELSE END)
0110 

this works... writes the chars between 255 -160 including 160

2 >>>

Code:

0100 mov ah,06
0102 mov cx,0000
0105 mov dx,184f
0108 mov al,00
010A mov bh,0F
010C Int 10
010E mov ah,2
0110 mov bh,00
0112 mov dx,0000
0115 Int 10
0117 mov dl,41
0119 Int 21
011B Int 20
011D

and this works too clears screen and writes white char "A" to the 01x01 coordinates