I personally have used Gemulator in the past for working in the Atari world.. Its a fast emulator and generally pretty reliable once you've got going.
So as I didn't have it on my computer, here's a guide from the beginning:
1. Get Gemulator -- either the smaller version (Gemulator 2000) or the latest 'beta' version which may be faster on your computer.
2. Next step is to find some roms. Of course that's no longer as much of a hassle because there's a freeware (new development) ROM which you can use to get you started called 'EmuTOS'. Available from
Personally, I also find that Tos 2.06 to be pretty reliable (you can either find a working machine with it already installed and dump it to floppy and copy that to your pc, or find an alternate source)
Either way, the older Gemulator expects you to call the rom TOS.IMG and doesn't really make it easy to switch between different roms in the same path.
Gemulator lets you access your PC hard drive as a 'C:' drive etc. so you can put Atari applications into an Auto folder and boot with winsizer.prg in there to get a high resolution (I find 640x480 in 16 colours to be sufficient)..
So then all that's left to do is download software (usually zipped) and stick it on your hard drive.
Of course there's the slight problem that some software is for better machines and setups than what I've got working so far, so as I go on I'll find more useful apps and utilities to get the most from the system.