Get on a PC with the DJGPP compiler. You can install the compiler on your own computer by getting the following files:
djdev203.zip
bnu2112b.zip
gcc2953b.zip
gpp2953.zip
mak3791b.zip
txi40b.zip
faq230b.zip
gdb500b.zip
csdpmi5b.zip (needed for DOS OS only)
rhide1478b.zip (integrated development environment)
You can get these files from http://www.delorie.com.
Make a directory for DJGPP (say, C:\DJGPP), and use
WinZip or another program to extract the files from the zip archives
into your DJGPP directory. Add C:\DJGPP\BIN to your path, and
set the environment variable DJGPP to C:\DJGPP\DJGPP.ENV:
PATH=%PATH%;C:\DJGPP\BIN
SET DJGPP=C:\DJGPP\DJGPP.ENV
You will then be able to use the gcc compiler.
Enter the following program hello.c using a text editor:
#include <stdio.h>
main()
{
printf("hello, world!\n");
}
Compile the above program with the following command:
gcc -o hello hello.c
You should have a file called hello.exe. Run by typing
hello on the command line.
This may not work in DOS. DOS needs something called DPMI to allow the use of
32-bit programs with the 16-bit DOS operating system. If the above programs
(gcc or hello) will not run, install the DPMI server
cwsdpmi with the following command:
cwsdpmi -p
and try compiling and running hello again.
Instead of using gcc as a command-line compiler, you may use the Integrated Development Environment RHIDE if you prefer. This will give you access to an editor, the compiler and a debugger all in one window. Just type rhide at the command line prompt, enter the program using the editor, and use the pull-down menus to compile and run the program.
Here is a program status.c to read the status of LPT1:
#include <stdio.h>
#include <pc.h>
#define P_STATUS 0x379
main()
{
int status;
status = inportb(P_STATUS);
printf("status = 0x%02x\n",status);
}
Compile the above program with the command
gcc -o status status.c -lpc