1.伪代码算法：
Set sum to 0
Read num1
Set sum to sum+sum1
Read num2
Set sum to sum+sum2
Read num3
Set sum to sum+sum3
Write sum
2.
得到的机器指令如下：
12 00 0B 00 00 00 00 00 00 00 00 C1 00 03 31 00
05 61 00 05 31 00 07 61 00 07 31 00 09 61 00 09
E1 00 03 39 00 03 00 zz
3.整理出的汇编语言
BR main
sum: .WORD 0x0000
num1: .BLOCK 2
num2: .BLOCK 2
num3: .BLOCK 2
main: LDWA sum,d
DECI num1,d
ADDA num1,d
DECI num2,d
ADDA num2,d
DECI num3,d
ADDA num3,d
STWA sum,d
DECO sum,d
STOP
.END