MacTerminal: Eliminating the X0 Command



I have discovered that MacTerminal sends out a command that is not always
accepted by the telephone company. If you do the automatic dialing, using Dial
in the Phone menu, the Macintosh sends the following:

ATS0=0 E0 V0 X0 H0 cr
AT cr
ATDT number cr

The problem is the X0. This puts the modem in a "blind dial mode." In other
words, the modem does not wait for a dial tone before it starts to dial. This
doesn't always work, depending on what kind of telephone system there is.

Is there any way of changing this command sequence, so that MacTerminal doesn't
send X0?

To change the X0 in MacTerminal's dial string to an X2 or X4 requires the use
of a file editing utility such as FEdit or SEdit. Make a working copy of
MacTerminal first, and open it from the utility. Do an ASCII search for
"ATS0" (the 0 is a zero). Within one block, there should be two occurrences of
"ATS0=0E0V0X0H0". Edit the "X0" to "X2", being careful not to add any extra
text. Write the sector back to disk.

It would also be a good idea to modify MacTerminal's version resource, so that
users can easily tell this copy has been modified. Using ResEdit, open
MacTerminal's vers resource ID#1. Modify two strings as follows:

Abbreviated string "2.3.1"
Change it to "2.3.1.x2"

Get Info string "2.3.1 Copyright c Apple Computer, Inc. 1983-1989"
Change it to "2.3.1.x2 Copyright c Apple Computer, Inc. 1983-1989"

Remember that this is an unsupported patch, and could cause problems if
MacTerminal encounters result codes it doesn't expect. By changing the X0 to
X2 or X4, you immediately expand the set of result codes that MacTerminal may
see. If it doesn't handle these well, the results can be unpredictable.


Published Date: Feb 18, 2012