Monitor I/O Procedures; Introduction; I/O Procedures - ZiLOG System 8000 User Manual

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SECTION 4
MONITOR I/O PROCEDURES
4.1 Introduction
The I/O procedures most frequently used in the Monitor Pro-
gram are given in this section. These procedures are
accessed by system calls in user programs to perform console
I/O functions.
4.2 I/O Procedures
TYIN
Description
Gets a character from the keyboard buffer. If the buffer is
empty, this procedure waits for a character to appear. The
character is stored in register RLO, and the contents of
register RHO are lost.
Example
CONSTANT
TYIN
:=
%04
SC #TYIN
(character in RLO)
TYWR
Description
Displays the character in RLO. The character is not
dis~layed
if the XOFF character has been received before
this procedure is executed. In this case, the procedure
waits until an XON character is received from the console
before displaying the character in RLO. If the character to
be displayed is a carriage return, the zero flag is set, and
RHO is lost.
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