MascOS

16-bit Real Mode operating system made entirely in Assembly.

Current situation of the project

The latest version shouldn't have bugs but I did fix every one of those I have found. I tried to run these 2 DOS games: DOS Defender, an Asteroids clone, and Floppy Bird, a Flappy Bird clone. They work but I can't fully test DOS Defender because I don't have a joystick. Other MS DOS programs can theoretically run on this not so good operating system, but keep in mind I haven't tested every program and I haven't implemented everything needed for those programs to behave without issues. The "stable" version doesn't have FAT12 and it's there for no reason, other than boosting my energy when I see how much progress I have made since I began this project.

I have tried to boot MascOS with a floppy disk(3.5 inch, 1.44MB) from an external usb floppy drive, and it worked almost flawlessly. It was tested on a Toshiba NB250 laptop.

If you want to learn how to create program for MascOS check the documentation.

Why MascOS

It's a learning project. I thought creating an operating system that targets old hardware would be a fun experiment to deal with.

Running the operating system

You can use the .flp image provided in the latest release or compile yourself the operating system. For the last one refer to the Compiling section of this file. It's very simple, but first you need to install Qemu (you need qemu-system-i386).

Arch

sudo pacman -S qemu-base

Ubuntu/Linux Mint

sudo apt install qemu

After installing Qemu just type:

make run

It uses PulseAudio to emulate the pc speaker, so if you're having troubles to run the operating system use this command instead:

qemu-system-i386 -fda Build/MascOS.flp -M smm=off -no-shutdown -no-reboot \
	-cpu 486 -rtc base=localtime,clock=host

If you want to run this on real hardware you need a computer with legacy BIOS and not a modern UEFI system, since MascOS aims to run on old hardware, and it will, hopefully without blowing up anything. To get the operating system image you can head to the Releases page, choose the latest release and download the .flp image, alternatively you can compile the os.

Compiling

To compile MascOS you need these packages:

• Nasm

After installing the packages open a terminal window and clone this repo with:

git clone https://github.com/leo007er1/MascOS.git && cd MascOS

To compile the latest version run this command. You need sudo permissions because the Makefile mounts an image to /dev/loop7.

sudo make

You can also choose to compile one of the oldest versions, v0.1.2. There's no purpose for this code to be there other than see how far I have come since I started the project. Note that after compiling it will automatically run the os with Qemu, so you need that installed.

make stable

Also if you want to remove the compiled files and the os image run:

make clean

Troubleshooting

OS

1. Why does the text in the edit program blink?

The VGA driver disables bliking to allow to use all 16 colors for background on real VGA hardware. Unfortunately on simulated VGA this doesn't work, and the text blinks.

Compiling

1. losetup: Build/MascOS.flp: failed to set up loop device: Device or resource busy

Well if you run lsblk you can see your devices and where they are mounted. The Makefile uses /dev/loop7 to build the os, so if you see loop7 you need to change /dev/loop7 to something like /dev/loop8 in the makefile