21 - direct access output, then paper tape input.

Usage:

mme     gerout
vfd     18/BUFPTR,o6/21,h12/TERMID
zero    STATPTR,COURTESY

Where:

BUFPTR: points to a buffer that contains information for the I/O operation. See below for more details.
TERMID: is the terminal ID name.
STATPTR: points to a word where status information can be written.
COURTESY: gives the courtesy call address. This address is used if specified.

Description:

This version of MME GEROUT writes to a teletypewriter, then reads paper tape input. The size of the input buffer should be at least 31 words.

The format of the buffer indicated by BUFPTR is given below.

Word 0, upper: number (N) of additional words in output
               buffer.
Word 0, lower: address of input buffer.
Word 1, upper: number of characters to be output
               (maximum is 312).
Words 2-N:     ASCII output, right-justified in bytes,
               left-justified in words.

When MME GEROUT returns, a status will be filled into the word indicated by STATPTR. Below we discuss the meaning of each bit in this status word.

Bits 0-17:   Not used
    18-23:   VIP terminal status
             18-21:  0
             22 = 1  PRINT key pressed to initiate
                     transmission
             23 = 1  Transmission failed after 16 attempts
    24-26:   Not used
       27:   Abort (in general status mode, Break/Disconnect
                    waiting)
       28:   Not used
       29:   Connected to another slave program
       30:   Waiting to connect to slave program
       31:   Terminal idle
       32:   If on, communication modules in the central
             system cannot acknowledge I/O request because
             terminal is busy with I/O
       33:   If on, output transmission complete, and input
             has been put in user's buffer
       34:   If on, terminal has not called in and
             connected, or has disconnected
       35:   If on, operator sent BREAK which terminated
             operation

After the input has been read, the input buffer has the following format:

Word 0:    number of characters read.
Words 1-N: actual input.