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NONDESTRUCTIVE INPUT NO WAIT
command code = 5
ES:BX pointer to request header. Format:
length field
byte read from device
The driver must do the following:
A) return a byte from the device
B) set the status word in the request header.
If the character device returns busy bit=0 (characters in the
buffer), then the next character that would be read is returned.
This character is not removed form the buffer (hence the term
nondestructive input). This call allows DOS to look ahead one
character. |
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