x86 assembly get one byte from 32 bit register

Question

I'm programmig in x86 assembly language, and I found one problem. I call C function getch to get single character from stdin. But the problem is that the return value is stored in register EAX. And I want to know, how to get one character. Not 4 byte value. Thanks.

What do you want to do with it? Very often you can just ignore the existence of extra bits — harold, Oct 15 '13 at 18:22
Note: `getch()` typically returns 1 of **256+1** different values. Hard to fit into one `char`. — chux - Reinstate Monica, Oct 15 '13 at 18:31

score 7 · Answer 1 · edited Oct 15 '13 at 18:20

7

you can use one-byte part of the EAX that is AL

mov [MEMORY], al

AL is the LOW byte of the AX register. You also can use AH - HIGH byte of the AX

edited Oct 15 '13 at 18:20

Gangadhar

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answered Oct 15 '13 at 18:09

Mikhail Krayushkin

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x86 assembly get one byte from 32 bit register

1 Answers1