This is my (very old) attempt to create an operating system.

It is actually very simple kernel written in x86 assembly and C. In order to run it, it must be stored on 3,5" floppy disk. It uses custom file system (QFS). The system can run COM programs and allows to chat with single person through RS-232.

It is the result of my learning of assembly and C in the past (1999-2005).

• it can run user programs, offers just one system call (interrupt 21h) which causes the user program to exit
• it has custom filesystem, called QFS (Quick File System) with directories with unlimited nesting
• it has 2 "consoles" - one command console, accessible through F1 key, and a "chat" console, accessible with F2 key
• chat console can communicate with another QSS instance through RS-232 port, allows just one another instance (not multiple ones)

In the past, I used VMWare Player, but nowadays I use qemu. The operating system itself has to be on a floppy disk, which is prepared in QSS/bin/floppy.flp file. We need to pass it to qemu:

qemu-system-i386 -boot order=a -fda floppy.flp -no-fd-bootchk

NOTE: This command is without RS-232 support. I didn't have time so far to work it out in qemu.

The command above will start asking you a "nickname":

In order to load local files onto a floppy disk, you require QFS emulator, which is a DOS program understanding the QSS filesystem. Yes, this OS uses custom filesystem, called QFS (Quick File System). In order to run it, I use DOSBox:

> dosbox

C:\> cd QSS\bin
C:\QSS\bin> imgmount A floppy.flp -t floppy
C:\QSS\bin> QFSEMU.EXE

You will see the following screen:

In order to write some files in the floppy, it is a 2-phase process:

1. "Create file" -> creates empty file in the floppy
2. "Write file" -> First enter target file in the floppy, then source file in local filesystem. Better if it is in the current dir.

Prerequisities are:

• Borland C++ 3.1
• Turbo Assembler 3.0