Install git if you don't have

sudo apt install git

or confirmed by

git -version

Then copy this command and paste it in terminal.

cd ~ ; mkdir Test; cd Test; git clone https://github.com/zexhan17/assembly-lang-course.git

wait until clone done.

cd assembly-lang-course;

Install unzip command to unzip .zip folders in terminal or you can unzip by GUI.

sudo apt install unzip

unzip AssmSoft.zip folder.

unzip AssmSoft.zip

Note: if you unzip using GUI move all unzip file to assembly-lang-course

Install DOSBOX

sudo apt install dosbox

After, installation run dosbox command to run it.

dosbox

Now, in dosbox paste this command.

mount c ~/Test/assembly-lang-course

then

c:

Assemble a file

nasm c01-01.asm -o c.com

Run assembled file

afd c.com

Type quit in running file terminal to come back dosbox shell

If after changing files, they do not show up in dosbox, hit Ctrl+f4 inside the dosbox window to make changes