Question

i 在今天的考试中提出这个问题,我为这个问题写了某些法典。我要告诉我,哪里确实错了。

Problem: for an 8086 microprocessor,write code that does the following task. it asks for user to enter the data and it counts the keypresses..
on execution of the ALP,the first message is obtained "counting keypresses , press escape to stop." (without quotation marks) , if the user enters the escape, the second message "counting keypresses" is shown and the result of the count is stored in BX and shown in displayed in binary. also the keys pressed (while entering data) ,the input key shall be echoed in the next line.

Solution: (that i wrote)
.model tiny .data text1 db "counting keypresses,press escape to stop $" text2 db "counting keypresses" .code .startup mov dx,offset text1 ;displaying text1 (i guess so) mov ah,09h int 21h and bx,00h label1 mov ah,01h ;(getting input from user and incrementing bx on every click) int 21h inc bx cmp al,1bh ;comparing with escape np label1 mov dx,offset text2 ;if zero then do this i.e display text2 mov ah,09h int 21h mov dx,offset bx ;display bx mov ah,09h int 21h .exit end

i am not sure if the comments i added are suitable or not. i know my code wont be correct,infact it wont be correct at all,but i managed to write this on the basis of my one night preparation.so if anyone could tell me,what wrong i am doing,then i will be highly thankful. because i really need to perform well in the next exam.

Answer 1

你有基本的想法,但有一些细节。

首先,请:

cmp al, 1bh
np label1

我不敢确定什么是<代码>np。您所希望的指示很可能有jnz 标签1。如果<代码>,则这一条将适用。 Z 旗帜不定,意思是用户打上新闻社。

阁下有以下几个方面:

mov dx,offset bx ;display bx
mov ah,09h
int 21h

这不会奏效。事实上,这本表无法汇编,因为你可以不占用登记册。你们需要将BX的价值存储在记忆中,然后将这一记忆地址传给产出功能。因此界定了贵国数据领域的2倍价值:

count dw 0  ; counter for output
      db  $  ; terminate output

Then you can write:

move [count],bx
mov dx, offset count
mov ah, 09h
int 21h

You did say that you want to output the count in binary, but I m not sure you know the ramifications of that. If the user presses only two keys, the output will be a binary 0 and a binary 2, which might display as boxes, or nothing at all, or perhaps funky characters. I don t remember how the int21 functions interpret all the control characters. For sure, though, if the user presses 13 keys, all you re going to get is a carriage return. And if the user presses 36 characters, the output will be ... nothing. Because 36 is the ASCII code for $ , and that s the output terminator character.

If you want to do a better job of output, you ll need to convert the value in BX to hexadecimal or decimal (hex is easier) to ASCII characters, and output those. I don t have a sample at hand.

最后,我不回顾《公约》规定21项职能是保存登记册。 BX是否在整个电话中保存? 如果没有的话,请在打电话之前使用<代码>push bx;在接获时,则需要<代码>pop bx。否则,你们的计票将“不明确”。

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