There is no current way for HyperCard to dial a voice call over an all-
digital system, such as IBX, without the use of XCMDs.
The problem is that an IBX is a digital phone switch: it communicates with
the handsets digitally, instead of using an analog method such as tones.
HyperCard (or any program) cannot use these lines to generate a voice call,
because the handsets communicate with the switch using a proprietary (and
undocumented) protocol specific to that switch. The only way to originate a
voice call from HyperCard is to use a hardware interface that understands
analog communications specific to the switch.
If you want to generate a data call, one instrument that can be used on IBX
is an ADI (Asynchronous Data Interface), and there are similar instruments
available for other switches. The ADI communicates with the Macintosh using
ASCII, much as a modem communicates. HyperCard, using XCMDs to perform the
serial I/O, can originate a data call and communicate with the answering
end. A package of serial XCMDs is available through APDA.
For more information, search under: "APDA".