Yamaha Mio, Руководство по обслуживанию

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RS-232 Handler Functions and Tables
This section contains a list of all input/output and XIO calls to the RS-232 "R:" handler of the MIO.
Note that IOCB is an input/output channel number that indicates what OPEN device shall receive or
provide data. For most XIO calls, you may use any legal IOCB number as long as it is NOT open to
any other device. From Atari BASIC, you may use IOCB numbers 1 through 7 (0 is reserved for
editing "E:" I/O).
Note that IOCB #7 is used for the BASIC LPRINT statement and IOCB #6 is used for graphics mode
functions from BASIC. Also, if using SpartaDOS, IOCB #4 and IOCB #5 are used while doing output
and input redirection respectively (via the DOS PRINT command and batch files).
All the syntaxes use just "R:" for the device name since there is only one RS-232 port on the MIO. In
fact, if you do use a port number (ex. "R2:"), it is simply ignored and treated the same as "R:".
All the function formats are given in their Atari BASIC form. If using assembly language or some
other high level language, refer to the language manual for its equivalent form.
Opening the RS-232 Port
Syntax
OPEN #IOCB,Aux1,0,"R:"
Remarks
This function opens a channel to the RS-232 port in pseudo "non-concurrent" mode. To remain
compatible with the 850 and P:R: Connection, the MIO has a flag indicating whether an XIO 40 (set
concurrent mode) has been performed since the last OPEN command. If it has not, then the
STATUS command returns the state of the handshake lines, whereas if in concurrent mode, the
STATUS command returns the number of characters in the input and output buffers.
Aux1 contains the I/O direction bits — 4 for input only, 8 for output only, and 12 for both input and
output (which is equivalent to 13 of the 850 interface). Many XIO calls do not require that you open
an RS-232 channel first, however, it is generally a good practice to open the channel first. Care
should be taken when setting the state of the handshake lines; if you set DTR false, the transmitter
and receiver are disabled. Therefore, you must re-enable them by setting DTR true before
continuing with normal operation.
When the channel is opened, both the input and output buffers are cleared. Also, the RTS and DTR
handshake lines are set true (to the ready state).
Closing the RS-232 Port
Syntax
CLOSE #IOCB
Remarks
This statement closes the IOCB connected to the RS-232 port. This simply shuts down the IOCB;
the RS-232 port remains untouched except that the system waits until all data in the output buffer
has been transmitted.
MIO Service Manual Page 65