CHAPTER 10
UNATTENDED MODE

The unattended mode will let you or your friends call and access your system
from a remote location. The remote user can leave a message in the buffer or in
a disk file or retrieve a message from the buffer or disk. Disk files can be
sent to or received from the remote user's system using either the XMODEM
protocol or the MMGR protocol supported by this program. The remote user can
also change logged drives and look at the directory (catalog) of your disks.

After you specify the welcome message and password, no further action is
required on your part. Your system will automatically answer calls, send the
welcome message, ask for and verify the password, provide help menus, and hangup
when the remote user is finished.

To use the unattended mode, you must have a modem which can answer the phone in
the answer mode, detect the remote carrier, and hangup either automatically or
under the direction of this program. The following modems are among those which
have these capabilities:

1) Apple Modem 300/1200, or Personal Modem
2) Applied Engineering Datalink
3) E+E Avatex 1200
4) Hayes Smartmodem 300/1200/2400 or 1200A
5) "Smart" modems which are Hayes-compatible
6) Hayes Micromodem II or IIe
7) Novation Apple-CAT II
8) Novation Smart-Cat
9) Prometheus Promodem 1200 or 1200A
10) Transend ModemCard
11) US Robotics Courier 2400
12) Zoom Modem ][e
13) Most auto modems

There are dozens of modems in category 5) which are compatible with the Hayes
Smartmodem command set. All of the ones tested with this program worked in the
unattended mode. However, there may be a few which are not exactly compatible
and do not operate reliably in this mode.

If you are using an external "non-smart" modem, you must enable carrier control
and interface the modem carrier-detect (DCD) signal properly to your computer.
This interface is described in Chapters 4 and 11. If you are using an internal
plug-in modem or an external "smart" modem, you may set carrier control to ON or
OFF. If you set carrier control ON, you must interface the external modem
carrier-detect signal to your computer.

The Novation Apple-CAT II will operate in the unattended mode using any of the
three drivers you may have installed for this modem. Unattended operation with
the Apple-CAT in the 202 half-duplex mode will have some slightly different
characteristics than with the other modes; we will describe this later in this
chapter.

The diagram shown below shows how you can enter or exit the unattended mode.


          TERMINAL ---U--->    UNATTENDED
          MODE      <-QY--    - MODE

You can enter the unattended mode by using the U command in the terminal command
mode. The remainder of this paragraph applies to the DOS 3.3 version only. In
the DOS 3.3 version, the work disk must be in the same drive that the program
was started in. If it is not in the same drive, the unattended program module
will not be found and the the program will attempt to return to the terminal
mode. If the work disk is not in the same drive, the terminal program module
will not be found either and the program will halt. An error message will prompt
you to insert the work disk in the drive and press any key to re-start the
program. After returning to the terminal mode with the work disk in the proper
disk drive, you can try to enter the unattended mode again with the U command.

After a few seconds of disk activity, the program will ask you to enter the wel
come message. This is the "hello" message which your system will send to the
remote caller when your modem answers the phone. The welcome message must not
exceed 64 characters and can not include control characters. You may use the
backspace key to edit your entry. After entering the welcome message, enter
[RETURN]. If you don't want to have a welcome message, just enter [RETURN]
alone. If you want to quit the unattended mode, enter [ESC].

Here are five example welcome messages:

Welcome to the IMSAI users group.
Joe: Read the message in file "TO.JOE".
Frank: Leave your arrival time in the buffer.
Call 555-1212 for more info.
THIS IS A PRIVATE SYSTEM.

After you enter the welcome message, the program will ask you to enter the
password. This is the password the remote caller must use to access your system.
The password must be 16 characters or less. It may consist of upper-case
letters, numbers, or punctuation symbols. You may use the backspace key to edit
the password. After you have specified the password, enter [RETURN]. If you
don't want password protection, just enter a [RETURN]. If you want to quit,
enter [ESC].

After you enter the password, the modem will switch to the answer mode. This may
take a few seconds. You will then see the following message:

Waiting for call 01

The 01 means your system is waiting for the first caller. This number will be
incremented for subsequent calls. Your system is now ready for a call and there
is nothing further for you to do. If you want to quit this unattended mode,
enter [ESC]. A few seconds may elapse before you are asked to confirm this.
Enter Y (for Yes) if you want to quit and return to the terminal mode. Enter N
(for No) if you want to remain in the unattended mode.

If you want to change the welcome message or password, you must exit the
unattended mode and enter it again. These two entries can be entered only during
initial execution of the unattended mode.

The unattended program will not switch baud rates automatically. You must select
the desired baud rate while you are in the terminal mode before you enter the
unattended mode. You must tell all potential callers which baud rate your
unattended system is set up for. (Don't forget to tell them the password also).


REMOTE CALLER

The preceding discussion described what you have to do to set up your system for
unattended operation. The remainder of this chapter will cover what you have to
do if you are the remote user calling the unattended system.

You do not have to use MODEM MGR or an Apple computer to call the unattended
system. You can use any software and any computer as long as you are able to
transmit a CR character and the escape character.

Before calling the unattended system, be sure your baud rate matches the baud
rate of that system. The unattended system will echo any characters you send and
will send a LF after each CR echoed. If you ar e using MODEM MGR, be sure your
program is in full duplex and your program is not sending LF characters after CR
characters. (Unless you are using the 202 mode, which we will discuss later).
This is the same setup you would use to call an information or bulletin board
system. Use the F and I commands if necessary to set this operating environment.

Call the unattended system in the originate mode. The unattended system will
answer the phone and enable its answer-mode carrier. Your modem should respond
with its originate carrier. Wait a few seconds for both modems to go online,
then send a CR by pressing the [RETURN] key. If your remote system does not have
a [RETURN] key, try control-M. If the unattended system doesn't send the welcome
message, wait a second or two and try again. The CR character must be sent
before the unattended system will respond.

When the unattended system receives your CR, it will send you the welcome
message (if there is one) and ask you for the password. You must send the
correct password. If you make a mistake in entering the password before entering
[RETURN], you may use the backspace key and correct your entry. If you send the
wrong password, the remo te system will warn you and allow you to make two more
tries. If you do not send the correct password with the three attempts, the
unattended system will hang up.

After the password is successfully recognized by the unattended system, it will
send you the following prompt which indicates it is awaiting your command:

     [Command?]-->

Note: Most of the command and status messages sent by the unattended system will
be enclosed in [ ] brackets. This will help you to distinguish between the
commands and status of your system and the commands and status of the unattended
system. Some unattended system disk error messages will not be enclosed in [ ].

If you do not see the [Command?]--> prompt, you can set the unattended system
into the command mode by sending an escape character. If you are using MODEM MGR
to access the unattended MODEM MGR system, remember that you must type [ESC]
twice to send the escape character (unless you have redefined the terminal
command key). When you enter [ESC] the first time, you will see your own
Command? --> prompt. After you enter [ESC] the second time, the escape character
will be sent and the unattended system should reply with the [Command?]-->
prompt. If you lose track of the unattended system status, just keep entering
[ESC] until you see the bracketed [Command?]--> prompt from the unattended
system. If you have changed your terminal command key to some other key, just
type [ESC] once to send the escape character to the unattended system.

If you send the ? character as a command to the unattended system, it will send
the menu shown in below. These are the commands the unattended system will
respond to. These commands are similar to the commands used in the terminal and
transfer modes, and will be briefly described.


               REMOTE COMMANDS
               ~~~~~~~~~~~~~~~

     B: Buffer ON/ OFF   C: Clear buffer
     R: Restore buffer   V: View buffer
     L: Look at status   H: Hangup
     D: Disk functions   X: XON/XOFF
     1: Rcv MMGR file    2: Snd MMGR file
     2: Rcv XMODEM file  4: Snd XMODEM file



     [DISK COMMANDS]     [DISK COMMANDS]

     Drive= 1            Prefix=/ MMGR/

     C: Catalog          C:Catalog
     R: Read file        R:Read file
     W:Write file        W:Write file
     D: Drive            P: Prefix
                         D: Drive Figure


If you send a character to the unattended system which is not one of these comm
ands, the unattended system will exit the command mode and enter the terminal
mode. If you send an escape character to the unattended system while it is in
the terminal mode, it will switch to the command mode. This is similar to the
type of operation used in the normal (attended) terminal mode.


B: BUFFER ON/OFF

The B command will toggle the capture buffer of the unattended system on or off
. When the buffer is on, any text you send to the unattended system will be
captured in its buffer. You can send text from your keyboard or you can send
text from one of your disk files using any one of the non-protocol methods in
your transfer mode.

If your disk file is sent with a non-protocol transfer and it has an escape
character in it, it will switch the unattended system into the command mode. The
character in your file following the escape character will be considered a
command by the unattended system and some undesired response may take place.

If your disk file has some unusual characters like the escape character in it,
use a protocol transfer to send it to the unattended system. Protocol transfers
with the unattended system will be covered later.

Since any user can clear the buffer of the unattended system, you should save
anything of significance you have sent to the unattended system to its disk. If
the buffer is off, received text will not be captured in the buffer of the
unattended system.


C: CLEAR BUFFER

The C command will clear the buffer of the unattended system. If you wish to
restore the buffer, see the restore command.

The buffer will also be cleared if you send files to or receive files from the
unattended system using a protocol transfer.


R: RESTORE BUFFER

If you have cleared the buffer of the unattended system and want to restore it
again, enter the R command immediately to restore it.


V: VIEW BUFFER

The V command will let the unattended system transmit the contents of its buffer
to you. You can halt and restart the transmission by sending the space character
and you can cancel the buffer transmission by sending a CR (except in the 202
mode).


L: LOOK AT STATUS

When the L command is sent to the unattended system, it will send you a summary
of its status. The following is a typical summary of the status of the
unattended system:

     [BUFFER ON]
     [XON/ XOFF ENABLED]
     [O/34047]
     [LAST DISK ERROR: NONE]

Note the status sent by the unattended system will be enclosed in [ ] brackets.

The first status line shows whether the buffer is on or off. The second status
line shows whether XON/XOFF is enabled or disabled. The third status line shows
the number of bytes captured in the buffer and the space left in the buffer. The
fourth status line shows the last disk error during protocol transfers. If a
disk error occurs at the unattended system when protocol transfers are being
performed, the remote system will not display the received error message because
it is looking for a handshake character instead. A disk error will also force a
termination of the transfer so the remote system may be busy closing the disk
file when the disk error message is transmitted.

Therefore, disk error messages during protocol transfers are saved for display
on the last status line. If a protocol transfer has been cancelled by the
unattended system, use the L command to check if a disk error occurred. After
you have requested the status of the unattended system by using the L command,
the last disk error status will be reset to NONE.


H: HANGUP

The H command will force the unattended system to hangup. You should always
execute this command when your session with the unattended system is completed
to provide a positive disconnect at the unattended system.


D: DISK FUNCTIONS

The D command will let you execute remote control of some disk operations at the
unattended system. When you enter this command, the unattended system will send
a [Disk command?]--> prompt. If you enter a ?, you will see either the DOS 3.3
or ProDOS remote disk functions menu in shown above.

The Drive= or Prefix= shows which drive or prefix is currently active at the
unattended system. The D command can be used to change the logged drive. In
addition, the ProDOS version allows the P command to change the active prefix.
The menu shows the disk commands you can use. These commands are similar to the
disk functions described in chapter 6, with the following differences:

1) You cannot erase a disk file directly. However, you can effectively erase an
unlocked disk file by over-writing it with another file having the same name.

2) You can read or write text files only. Use the protocol transfer to send or
receive other types of files.

3) With DOS 3.3, you cannot specify another disk slot. With ProDOS, you can spe
cify a prefix on another slot.


X: XON/XOFF

The X command will enable or disable the XON/XOFF handshake at the unattended
system. When XON/XOFF is enabled, the unattended system will transmit a
control-S when its input buffer is nearly full. If the remote system uses XON/
XOFF handshaking, it should stop transmitting. When the input buffer level
becomes empty, the unattended system will transmit a control-Q, and the remote
system can resume sending again.

When XON/ XOFF is disabled, the unattended system will not transmit any
handshaking signal.

If the remote system also responds to control-S and control-Q as handshake
signals, then XON/XOFF should normally be enabled at both the remote and
unattended systems.


1: RECEIVE MMGR FILE

The 1 command lets the unattended system receive one of your disk files using
the MMGR protocol file transfer. The unattended system will ask you to furnish
the filename or pathname under which that system will save the transferred file.
The file will be saved on the currently logged disk at the unattended system or
you can append a comma followed by D# after the filename to specify another
drive number #.

If a file with the same name exists on the drive at the unattended system, that
system will send you an error message. With protocol transfer to an unattended
system, you cannot send a file with a name which currently exists on the same
drive of that system. After you have specified a suitable name, you will receive
a ready-to- receive message. You must then switch to your transfer mode. Do this
by entering [ESC] to get into your terminal command mode (Command? -->
displayed) and Y to enter your transfer mode.

When you are in your transfer mode, enter the same 1 command. For your remote
system in the transfer mode, this is the command to send an MMGR file. Note the
same command number (in this case command 1) is used for both the unattended
system command and your transfe r command. This makes it easier to insure you
have picked the correct complementary commands ('receive' at the unattended
system and 'send' at your remote system).

After you specify the name of the file to send, the transfer will proceed in the
manner described in Chapter 9. Refer to that chapter for details. When the
transfer is completed, quit the transfer mode. When you are back in your
terminal mode, you will still be online with the unattended system.


2: SEND MMGR FILE

The 2 command lets the unattended system send you one of its disk files using
the MODEM MGR protocol file transfer. The unattended system will ask you to
furnish the filename or pathname of the file to send. The file should be on the
currently logged disk at the unattended system or you can append a comma
followed by D# after the filename to specify another drive number #.

If the file exists at the unattended system and it is not a DOS 3.3 text file,
that system will send you a [Ready to send] message. You must then enter your
transfer mode and prepare to receive the file. If it is a DOS 3.3 text file, the
unattended system will ask you whether it is a sequential or random text file.
See the discussion in chapter 9 regarding the differences in transferring DOS
3.3 sequential and random text files. If the file does not exist, you will
receive a [FILE NOT FOUND] message and will be asked for the name again.

When you are in your transfer mode, enter the same 2 command. For your remote
system in the transfer mode, this is the command to send a MMGR file. Note the
same transfer command number (in this case command 2) is used for both the
unattended system command and your remote command.

After you specify the filename or pathname to use for saving the file on your
disk, the transfer will proceed in the manner described in Chapter 9. When the
transfer is completed, quit the transfer mode and return to the terminal mode.

You cannot transmit any of the MODEM MGR main execution programs from the unat
tended system. These programs have names starting with the letters MDM (if DOS
3.3) or MDP (if ProDOS). If you attempt to have these files transmitted, the
unattended system will hang up.


3: RECEIVE XMODEM FILE

This command is similar to the 1 command for receiving a MMGR file. The major
difference is the XMODEM protocol is used instead of the MMGR protocol. You must
also specify the type of file under which the unattended system will save the
received file. The file types are either TXT, BIN, or BAS. The Integer file type
is allowed with DOS 3.3. When you enter your transfer mode to send your file,
use the same command number 3. Additional information on XMODEM transfers is in
chapter 9 and will not be repeated here.


4: SEND XMODEM FILE

This command is similar to the 2 command for sending a MMGR file. The major
difference is the XMODEM protocol is used instead of the MMGR protocol. You must
also specify the type of file under which your system w ill save the file sent
by the unattended system.

When you enter your transfer mode to receive your file, use the same command
number 4. Additional information on XMODEM transfers is in chapter 9.


TIMEOUT

If you don't transmit anything to the unattended system for a long period of
time, the unattended system will send you a [BYE] message and hang up. This is
an automatic disconnect in case you have become distracted by another more
important activity. This also provides an eventual hangup if you disconnect
without issuing the hangup command to the unattended system and that system does
not have carrier control enabled. To prevent timeout, you should occasionally
send a character or command to the unattended system to show you are still
there.


TERMINATION

When you are finished, the best way to terminate the session with the unattended
system is to execute the H command when that system is awaiting a command from
you. This will force the unattended system to hang up and reset for the next
caller. After the unattended system acknowledges the hangup command, you can
then hangup your system.

If the unattended system is not using carrier control and you hang-up your
system without commanding the unattended system to hang up first, the unattended
system will probably hang up also (if the modem disconnects automatically), but
the unattended system will not reset until it times out. This will make it
unavailable to any other caller during the timeout period.

However, if the unattended system is using carrier control, it will hangup and
reset immediately even if you hangup first. It is a good practice at the end of
a session to issue the hangup command to the unattended system even if it has
carrier control.


MANUAL OVER-RIDE

The operator of the unattended system (SYSOP) can enter commands and text from
his keyboard and the system will respond as if they were received from the
remote caller. This "attended" operation can be useful in providing assistance
for a caller who is not familiar with the system commands.


BUFFER OVERFLOW

Although a large input buffer (not the same as the capture buffer) is used at
the unattended system, buffer overflow can occur if you are using a non-protocol
transfer to send a long file from the remote system at the effective baud rate
continuously without XON/XOFF handshaking.

The unattended system echoes incoming text and inserts a LF after each CR
received. Therefore, the unattended system is normally sending more characters
than it is receiving. If the incoming text is at the maximum rate (the hardware
baud rate), the unattended system must send more characters, but is limited to
the same baud rate for sending. Therefore, it cannot echo the incoming text at
the maximum throughput rate forever. If the incoming text is non-stop,
eventually the unattended system buffer will overflow. Selecting a lower baud
rate is not a solution because although the rate at which characters are being
received is reduced, the sending rate is correspondingly reduced also.

This is not a problem with protocol transfers because the incoming characters
are not echoed and there are pauses between blocks transmitted.

To avoid buffer overflow on long non-protocol transfers, use a slower sending
pace or enable XON/XOFF at the remote and unattended systems.


SMARTMODEM ESCAPE CHARACTER

In the unattended mode, MODEM MGR changes the "smart" modem escape character
sequence from +++ to ---. This reduces interaction when both the remote and
unattended systems are using "smart" modems. Do not change the "smart" modem
escape character sequence.


APPLE-CAT II 202 MODE

If you are using the Apple-CAT 202 1200 bps half-duplex driver, you can also use
the unattended mode. Anyone calling your system must be using the same driver.
Most of the same features described earlier for the unattended system are
available, including protocol file transfers. One exception is the caller cannot
interrupt non-protocol trans mission of a disk text file or a view operation.

Since this is a half-duplex system, the caller must wait until the unattended
transmissions are completed before sending his commands. The carrier hang-on
time is reduced significantly on most unattended system transmissions so a
slight delay is all that is required.

Before you call the unattended system, use the terminal F command to place your
system in half-duplex and use the I command to insert a LF after every CR you
send.