MultiMobile MT128ZLX User Guide 5: Windows 2000 API Usage
151
MT128ZLX: Using APIs in Windows 2000
About APIs
The MT128ZLX-ST/NT operates in conjunction with three App lication Program Interface software
packages: NDIS, VCOMM, or CAPI. This chapter presents examples of how t he MT128ZLX can be used
with these APIs. The CAPI-compliant program used in these examples is RVS-COM Lite.
Each API contains software components that interact with the operating system of the computer in which
the MT128ZLX is installed. Each API adds communications functional ity to the system. Each of the three
APIs adds a somewhat different set of features to the system, as summarized in the table below and
described more fully in subsequent sections.
API Full Name Functionality
NDIS Network Driver Interface
Specification dial-up networking (DUN)connection, network
interface card (NIC) emulation
VCOMM Virtual Communications
Driver dial-up networking (DUN)connection,
modem emulation
CAPI Common ISDN Application
Program Interface dial-up networking (DUN)connection, modem
emulation, G3 and G4 FAX, V.110, V.120, X.75,
HDLC, interface to ISDN features and services
The NDIS API
NDIS allows Network Interface Cards (NICs) to work with each other, with the o perating system, and with
higher order protocol drivers. NDIS is an interface that facilitates development of NIC drivers. NDIS
program routines can implement the functions that NIC drivers must perform. These include interaction
with protocol drivers, the handling of hardware interrupts, and interface with underlying NICs by d e a ling
with registers, port I/O, and other functionality. NDIS allows drivers to be developed in high-level
programming languages, such that their creation and implementation are platform-independent.
The VCOMM API
The communications device driver known as “VCOMM” provides protected-mode services. It allows
makes ports and modems available to Windows-based software appl ication programs. VCOMM also uses
plug-and-play functionality to simplify the installation and configuration of communications devices.