RotorDRV TSR to EasyComm 2 Adapter

Must Be Art > Software > KCT-EC2


KCT-EC2 is a DOS TSR (terminate-and-stay-resident) program for use with applications that use the antenna rotator driver interface defined by the Kansas City Tracker (KCT) and an external antenna controller that accepts the EasyComm 2 command protocol.

The KCT software interface allows application programs, especially satellite tracking programs such as InstantTrack, to control a two-axis antenna rotator without needing to know any details of the hardware. The hardware driver, referred to as RotorDRV, is installed as a TSR program, and accepts commands through software interrupts. KCT-EC2 fills this role.

The EasyComm 2 protocol defines a set of commands between a host computer and an external smart controller, via an asynchronous serial ("RS-232") port. The computer is responsible for keeping track of time and for computing the location of the target (usually a spacecraft in orbit). The computer sends azimuth and elevation angles to the controller, and the controller takes care of moving the antennas so as to point in the specified direction.

This program is a sort of adapter between the two types of interface. It looks like a KCT driver to the application program, and sends EasyComm 2 commands out the serial port to the external controller.

The package actually consists of two programs. KCT-EC2.COM is the TSR driver itself. EC2START.EXE is a command-line application program that configures the TSR driver (tells it which COM port to use) and can enable or disable the TSR driver.

System Requirements

To run KCT-EC2, an environment capable of running an MS-DOS TSR program is required. This certainly includes all versions of MS-DOS beyond 2.0. This program will also work under Windows 3.1, 95, and 98, but probably will not work under Windows NT, 2000, or XP.

The serial port used with KCT-EC2 must be a 16550A-compatible UART, or equivalent, with 16-byte or larger FIFO. This is true of all modern PC serial ports (except USB serial ports), but older ports or highly-specialized multiport boards may not be compatible.



Current Status

Initial alpha test, version 0.03 released June 27, 2002. Works on my computer. No other test results yet.


Has been rattling around in the back of my mind for years. First working version in May 2001.

Known Bugs



KCT-EC2 alpha test versions maybe distributed freely and may be used freely for non-commercial purposes only.

Source Code

Source code in assembly language for Microsoft MASM 5.1 (for the TSR driver) and Microsoft C 6.00A (for the control application), with a Microsoft NMAKE makefile that builds both, will be distributed freely after some alpha testing confirms the viability of this design approach.


KCT-EC2.TXT - user manual (plain text, 5K)

DRVSVC.TXT - programmer's specification for the KCT software interface

INTSPEC.TXT - programmer's specification for the interfaces used by InstantTrack OrbitDRV

EASYCOMM.TXT - original programmer's specification for the EasyComm and EasyComm2 protocols.


KCT-EC2 0.03 (zip file, 9.5K)

Copyright 2002 Paul Williamson. Comments to kb5mu@amsat.org