Prepare New Floppy Disks for Saving Files (15-30 mins)

Task: Prepare New Floppy Disks for Saving Files

Needed: Atari computer, disk drive, floppy disks, and DOS

Time: 15-30 minutes


I am a big fan of cartridges but understand and accept that the floppy disk is important and useful. I still have all of my floppies from back in the day. I have also accumulated hundreds of floppies from the collections of others over the years. These are really fun to explore and it is amazing to me that about 95% of these still work. However, there comes a time in your retrocomputing hobby when you want to make new floppies for a practical reason or just to relive the experience. Fortunately, you can still purchase new in box floppies from the 1980s on eBay. A box of 10 disks sells for about $15. I provide below some simple instructions if it has been awhile since have done this as well. It will all come back quickly!


Step 1 – find an unused or new diskette

As I mentioned above, you can find new old stock 5.25″ floppies online for about $1 to $2 per disk. You might also find some unused disks in your own collection.

New Disks
New Disks

Step 2 – boot your Atari into DOS

If you already have one or more disks with DOS on it you are all set and can load it to complete the steps below. However, if you don’t have DOS there are several things you can do. First, you can buy used disks with DOS on them from eBay. For example, the Atari Master Diskette that came with different versions of DOS is regularly available on eBay although there is no guarantee it will still work. Another option is to connect your Atari to your PC/Mac with an SIO2PC cable that then provides access to disk images (i.e. .ATR files) through software such as APE from AtariMax. I will cover this modern method in a future post.

Wikipedia has a nice summary of all the different version of DOS from Atari and other brands. Here is an article on “Everything you wanted to know about every DOS” from a 1985 issue of Antic magazine. DOS 2.5 is a good place to start and will work with all the Atari disk drives. I like DOS 2.0 for my 800 and 810 setup. I also used SmartDOS back in the day.

Step 3 – format the disk

The first thing you need to do is to initialize or format the disk. I prefer to use an Atari 800 with an 810 drive since this is what I used as a kid. This means that I am limited to single-sided (SS) reading and writing and single-density (SD). An SD disk holds about 90k of data organized into 720 sectors of 128 bytes each on one side. You can of course flip the disk over and write to the other side giving you double the storage. A double-density (DD) disk holds about 180k per side. Unfortunately, only the Atari XF551 disk drive has true DD. Drives from other brands such as the popular Indus GT or Rana could also work with DD. The 1050 drive can read and write 130k per side which means it is in between SD and DD even though is was advertised as DD. This was later called Enhanced Density (ED). Go figure! The good news is that you can buy DS-DD disks online and format them to SD or DD using any of the drives you want to use. DOS 2.5 works with SD, ED, and DD.

Once you have booted DOS insert the blank disk into the drive and choose the format disk option. This is option ‘J’ on the DOS 2.0 menu that I use with my 810 drive. The formatting doesn’t take long. Don’t go far.

Step 4 – write DOS to the disk

Once the disk is formatted you will likely want it to also have your favorite version of DOS. Most of the DOS versions have an option to write DOS to the disk. In DOS 2.0 this is option ‘H’.

Step 5 – save a program to the new disk

I went through all these steps recently to make a new disk for the Atari 1020 printer demo program that I mentioned in the previous post. I typed the program in using the BASIC cartridge and then saved it to disk using the following BASIC command.


This writes the BASIC program to the disk in drive 1. Remember that filenames can’t be longer than eight characters. To load the program from disk you can type the following.


New Floppy Disk
New Floppy Disk


This is a very simple exercise intended for those of you that are doing this for the first time in 30 years or more. I had to refresh my memory the first time back in the saddle. Hopefully writing it down here will make it easier for the returning Atari 8-bit enthusiast! Also, you can always consult one of the many books from back in the day that have been scanned and provide free online. “Your Atari Computer” (a.k.a the purple book) is a great place to start for a refresher course. Happy disking!