Two things first:

First, get a DOS boot disk from Unzip the package, find the file 622C.IMG, and copy it to the aemula folder:

Second, download a sample hard disk image ( Unpack the file and put sample.img in the same folder.

Make sure both the boot disk and hard disk image are selected via FD and HD button respectively. Then press Power button, Aemula will now boot from the floppy.

If this is the first time boot, then you need to do some extra work. Edit the file config.sys by typing the following command:

A:> edit config.sys

Comment out the line

DEVICE=cd1.SYS /D:tomato

so that it looks like this:

rem DEVICE=cd1.SYS /D:tomato

Then edit autoexec.bat, and make sure the following line is also commented out:

rem MSCDEX.EXE  /D:tomato /L:R
The point here is to save as much memory as possible for games.

Now hit Power button and restart Aemula. You can start playing by:

A:> C:

Note: You can replace the games on the disk with disk image utilities like WinImage.