After the Internet became popular, websites such as AtariAge started creating articles to announce the latest tool for Atari personal computer development. It was called Altirra. Currently it appears they have released version 3.00. The version I am using for this example is 2.81.
This tool is an emulator. What that allows you to accomplish is reading in Atari disk files from the Internet or even accessible from your personal computer via an SD Card reader. I currently own one and plan to do a review on it soon. However, due to managing multiple websites, working a 9-5, I am a very busy person.
Atari Altirra ROM Files
Anyway, you will need to access some special ROM files to get it working. The best way to think of this is to sit in front of your actual Atari personal computer system and imagine what it takes to boot it so you can start writing programs. First you can boot the system clean just by plugging it in and firing it up. The system will boot into Atari Basic. So the first tip is to be sure you have a copy of the Atari Basic ROM file. You can usually download these online these days for free.
Next if you plan to boot a disk drive, you will need to attach another special file to read the disk drive. The cassette drive also has a separate file to boot from. To simpify this I will demonstrate with some live screen shots using the Atari Altirra emulator as an example.
When you first load up the Altirra emulator you will be presented with the copyright screen. This is the normal standard mode without any ROMs in it’s memory.
Loading the ROM
As explained earlier, we will be loading in Atari Basic ROM to get the tool to boot into Basic mode. Click on the File menu, select Attach cartridge. This will immediately open up a file dialogue window on your desktop. Since I have already downloaded the Basic ROM file I will load it into the emulator. The file I am using is called ATARIBAS.ROM.
Next you will see a new dialog window that covers the main Atari Altirra screen. It is labeled Select Cartridge mapper. I usually leave this on the default of *1:8K since that is the system I want to utilize. Then just press the OK button to continue.
Atari Basic Start up Screen
Finally the Atari Basic window will appear. This is because Altirra has now accessed the correct ROM routines to manage Basic. This editor works in comparison to the original Atari 65xe. You can instantly start typing in a program or running immediate commands on the console. For example type in PRINT “I LOVE ATARI ALTIRRA!” and you should sent the message printed below the line you just entered. It also will sound just like your Atari Basic as you type in the message. Pretty cool.
As much as I would love to start demonstrating some Atari program, this guide is dedicate to the Altirra emulator tutorial so we will now be attaching a disk drive where we can save our programs in Windows. Click on the File menu again and select Disk Drives.
This pop up window is labeled Disk drives and will allow you to attach up to 8 drives at a time. Examine the rows labeled D1-D8. These are the areas where you will be assigning a disk drive file. Next click on the 3 dots to the right of D1. A new dialog window appears. Search for the disk drive file MYDOS45D.XFD or a similar disk drive file. After this the D1 will now be populated with the reference to that disk drive file. Press the OK button to return to Basic and close the pop up window.