Morse Academy supports RS232 and parallel port keying interfaces that are
commonly used by other programs, e.g. the K1EA Contest Logging program. This
interface is not the preferred one because it only supports a single
frequency. The audio feedback tones of 300 and 1800 Hz for MA's games is not
available. Still the ability to practice with the (P)roficiency session and
generate examination tapes makes it desirable to support these interfaces.
The ports COM1 (3FCh), COM2 (2FCh), COM3 (3ECh), COM4 (2ECh), LPT1 (37Ah), or
LPT2 (27Ah) can be selected for keying in the (O)ptions menu, when choosing
the (T)one generator option E. The keyed port address is displayed in
Hexadecimal. Morse Academy outputs a 1 to the port to close the key, e.g.
To open the key a zero is output to the port.
The pin outs for keying are:
Direct connection of your PC to a transceiver is NOT recommended. Isolation
is required between the PC and the equipment being switched. Interfaces such
as that designed by Jim Talens (N3JT) are commercially available. Write to
Jim Talens (N3JT), P.O. Box 19346, Washington, DC 20036.
OUT &H3FC,1 (in BASIC)
mov AL,1 (in MASM)
mov DX,3FCh
out DX,AL
RS232 Ports Pins 4 and 5 on a DB9 connector.
Pins 7 and 20 on a DB25 connector.
Minus nine (-9) volts indicates key open.
Plus nine (+9) volts indicates key closed.
(note voltages may vary from 6 to 12 volts,
depending on the PC manufacturer)
Parallel Ports Pins 1 and 17
Zero volts indicates key open.
Plus five (+5) indicates key closed.
(note voltages may vary, depending on the
PC manufacturer)
By Joe Speroni
Email: 