Re: please help this newbie running asm programs!!!

[Alfonso <a.martone@retepnet.it>]

> i am a newbie trying to port and run dos based 8086 programs under
> linux using as86, ld86 and elksemu. i have written a simple program

Under ELKS, you should use ELKS system calls (via INT 80h), instead of 
DOS calls (via INT 21h)...! :-)

If you want to port some DOS program, you must take into account that 
almost any program has to be modified and recompiled because:

- they assume DOS memory structures and interrupts (int 20h, int 21h, 
PSP, environment variables, etc)... ELKS programs are definitely 
*clean* with memory, hardware I/O, etc

- they assume DOS memory handling (i.e.: every program can use all 
remaining RAM upto 640k)... in ELKS, as in any Unix, a process cannot 
say "let's get all available RAM";

- they assume the can do everything with hardware; ELKS programs use 
the canonical "/dev/..." special files, and do not require special 
handling; i.e.: a screen terminal, a pipe, a disk file, a serial port, 
etc, everything uses the canonical open/read/write/close scheme (while 
DOS world uses a library for soundcard, the open/close for files; BIOS 
or write to screen-memory for terminal I/O, etc).

alf