|
Operating a modern ham shack with MS-DOS or Windows 3.11 brings amateur radio back to its pure hardware roots. Before sound card digital signal processing took over in the late 1990s, operating digital modes meant interfacing dedicated hardware Terminal Node Controllers (TNCs) via RS-232 serial COM ports.
Whether you are running an 80286, 386, 486, or early Pentium machine, MS-DOS and Windows 3.11 offer rock-solid, real-time serial performance without background OS interrupts interfering with time-sensitive data streams.
1. Primary Operating Capabilities
- Hardware Packet Radio (AX.25): 1200 baud VHF packet and 300 baud HF packet operating via hardware TNCs (Kantronics, AEA, TNC2).
- Classic Digital Modes: RTTY (Baudot), AMTOR, PACTOR-I, and CW (Morse code) keying/decoding.
- Keplerian Satellite Tracking: Real-time orbit calculation and antenna rotor control using period-correct orbital models.
- Terminal-Based Logging: Fast, keyboard-driven loggers that write directly to flat-file ASCII databases or DBF tables.
2. Essential Software Matrix
| Mode / Category |
Application |
OS Platform |
Description & Notes |
| Packet Radio (TNC) |
Packet Cluster / BayCom / Graphic Packet |
MS-DOS |
Industry-standard AX.25 terminal programs. Supports multi-connect terminal sessions. |
| Packet Radio (Win16) |
WinPack (v2.x) |
Windows 3.1x |
A clean 16-bit packet terminal for Win 3.11 using COMM.DRV over RS-232 serial ports. |
| Multi-Mode RTTY/CW |
HamComm (v3.1) |
MS-DOS |
Legendary software using a simple 1-transistor interface on the PC serial port for RTTY/CW. |
| SSTV Decoding |
JVFAX (v7.0) |
MS-DOS |
Decodes Slow-Scan TV and Weather FAX (WEFAX) using an LPT printer port simple ADC or sound card. |
| Satellite Tracking |
InstantTrack / Silicon Ephemeris |
MS-DOS |
Tracks OSCAR satellites and renders polar footprints; calculates Doppler shift updates. |
| Station Logging |
K1EA CT / Log-EQF |
MS-DOS |
Ultra-fast contest and general loggers optimized for low-RAM 16-bit x86 environments. |
3. Interfacing Hardware: RS-232, TNCs, and LPT Ports
In the DOS era, the PC does not handle modem processing internally; it delegates AX.25 packet framing to an external TNC:
- Serial Connection (COM1/COM2): Connect a standard 9-pin or 25-pin RS-232 cable from the PC serial port to the TNC (e.g., Kantronics KPC-3, AEA PK-232MB).
- Baud Rate Configuration: Set the terminal software serial rate to 9600 bps (8-N-1) for TNC-to-PC communication. The TNC handles the 1200 baud Bell 202 tones to the radio audio jack.
- Hardware Flow Control: Always use hardware RTS/CTS flow control in software config to prevent serial buffer overruns on 16550 UART chips.
4. MS-DOS Memory & Autoexec Configuration Tips
Running 16-bit ham radio utilities often requires maximizing conventional memory (below 640KB) and managing TSR (Terminate and Stay Resident) drivers.
CONFIG.SYS Optimization: Load HIMEM.SYS and EMM386.EXE to load serial drivers into upper memory blocks (HIGH,UMB).- Serial UART Drivers: If running higher baud rates under Windows 3.11, replace the stock 16-bit
COMM.DRV with CyberCom or SuperCom drivers to handle 16550A FIFO buffers reliably without dropping serial packets.
- Real-Time Clock Sync: DOS system clocks drift rapidly. Use a serial GPS parser utility (like
DOSGPS) at boot to update the system clock against UTC time before logging or satellite tracking.
|