Running AppleSoft BASIC from a modern mac on an Apple ][c

The Apple IIc is a remarkable device, and many working ones are still floating around. With the advent of genAI coding tools, there are lots of ways to develop better code in AppleSoft Basic, one of the core languages of the IIc. Figuring out how to run AppleSoft BASIC programs, written on a modern mac, on an original apple IIc, is not trivial.

Some solutions include keyboard emulators or modems, but this could require some intense hardware work. If requirements are fluid, we may be better off packaging up programs as disk images which we then use with SD card or transfer cable, or even writing our own physical floppies if we have a mechanism to write 5.25" floppies. This is what I detail below!

AppleSoft BASIC

Applesoft (integer) BASIC is a form of Microsoft BASIC written for the Apple I and II.

Example Hello World program:

10 PRINT "HELLO WORLD"

More example programs, including those used below can be found in this repo in the applesoft_basic_programs folder

Writing disk images containing our program

AppleCommander is the standard for composing disk images and has some built-in libraries for dealing with AppleSoft BASIC. Although our program will be written in AppleSoft BASIC, it needs to be properly tokenized/compiled to be read by the Apple IIc. Thankfully, AppleCommander has a utility for loading plaintext BASIC into disk images: https://applecommander.github.io/ac/#put-standard-input-basic-source-code-onto-disk-image-as-a-basic-file.

Converting a BASIC file to a disk image with the included script

We can add BASIC to be loaded 2 ways, either on a disk with DOS 3.3 Master preloaded, or on an empty DOS compatible disk. Generally, if we only have one disk drive (or disk drive emulator), we will want to go with option (1) since we will need the BASIC interpreter that comes with DOS

I have included a very helpful AppleScript called make_disk_image.scpt that automates this whole routine! Find it in the attached code.

The script can be run from any clone of this repository on a mac. Java is required in order for the script to run, and the script will prompt you to install Java if it cannot find a java installation.

Running through the process should be self-explanatory so long as you have a copy of this repo and one or more BASIC programs in text files, so no further instructions are given here.

Converting a BASIC file to a disk image without the included applescript

If you've used the applescript, skip to the next section, Where To Run Your Disk Image, below.

Otherwise, you can follow the format of the commands below, executed in a shell terminal in the root of this repository, to build disk images.

Adding images on top of DOS w/ Integer BASIC

# from the root of this repo
cp disk_images/reference/dos_3_3_master.dsk disk_images/created/helloworld_dos.dsk
cat applesoft_basic_programs/helloworld.bas | java -jar applecommander/AppleCommander-ac-1.8.0.jar -bas disk_images/created/helloworld_dos.dsk helloworld

# we can add multiple BASIC programs to one disk image
cp disk_images/reference/dos_3_3_master.dsk disk_images/created/myprograms_dos.dsk
cat applesoft_basic_programs/helloworld.bas | java -jar applecommander/AppleCommander-ac-1.8.0.jar -bas disk_images/created/myprograms_dos.dsk helloworld
cat applesoft_basic_programs/sample.bas | java -jar applecommander/AppleCommander-ac-1.8.0.jar -bas disk_images/created/myprograms_dos.dsk sample

Adding images to an empty DOS disk image

# from the root of this repo
java -jar applecommander/AppleCommander-ac-1.8.0.jar -dos140 disk_images/created/helloworld.dsk
cat applesoft_basic_programs/helloworld.bas | java -jar applecommander/AppleCommander-ac-1.8.0.jar -bas disk_images/created/helloworld.dsk helloworld

java -jar applecommander/AppleCommander-ac-1.8.0.jar -dos140 disk_images/created/sample.dsk
cat applesoft_basic_programs/sample.bas | java -jar applecommander/AppleCommander-ac-1.8.0.jar -bas disk_images/created/sample.dsk sample

Where to run your disk image

Using an actual Apple II + a disk drive emulator

Unless you have the (rare) hardware to write 5.25" floppy disks, you will need a hardware device to pretend to be a disk drive. The images (.dsk files) you created above are loaded via SD card onto this disk drive emulator device, which is connected to the Apple II. Such emulators tend to cost around $100

Suitable devices include:

• FloppyEmu (uses microSD)
• wDrive (uses SD)

Using a disk emulator but don't want to move an SD card back and forth?

Using a Wifi SD card such as eye-fi, toshiba flashAir, etc, you could enable wifi transfer of disk images to one of the above hardware disk emulators so that you wouldn't even have to worry about SD cards, just connect to the wifi sd network from your mac and drop the disk image files on there.

Using an actual Apple II + ADTPro

ADTPro is a program that, when running on both an apple II and a modern PC connected by some manner, allows transfer of disk images between the two.

The suggested setup for a modern PC to an Apple IIc involves a null modem to RS232 cable and a USB to rs232 cable. These cables can be purchased here

Alternatively, you can use a smartphone and perform the transfer over the audio jack, which may offer a more convenient "wireless" alternative.

Since we only need to run applesoft BASIC programs, and our IIc may not be ProDOS-friendly depending on the ROM chip it has installed, we just want the DOS 3.3 version of ADT if we can manage to get it working

• ADT (DOS 3.3)
• ADTPro

I haven't tested this ADTPro solution, so no guarantees

Using a software-emulated Apple II

Don't have an actual Apple II? You can use these emulators to test disk images by using the process above if you don't own actual apple II hardware:

• https://www.scullinsteel.com/apple2/ is an online apple ii emulator
• microm8 is an Apple II emulator for Windows

Loading your program from disk

If we are using a modified DOS master disk in single disk mode (option 1)

1. Insert our modified disk (image) in drive 1 (bootable).
   • Allow to boot into DOS (you should see "DOS VERSION 3.3 .... (LOADING INTEGER INTO LANGUAGE CARD)")
2. Run the program, using the program name you chose, via RUN MYPROGRAM
   • You do not need to specify disk, since by default it will look on the booted disk (D1)
3. If you need to exit (let's say you want to try multiple programs), hit RESET on the keyboard and RUN MYOTHERPROGRAM to run any other program on the disk

If we are using a DOS master disk + a custom disk via a single drive (option 2a)

1. Insert DOS 3.3 master disk in drive 1 (bootable). Allow to boot
2. Insert custom disk (image) in drive 1.
3. At the DOS command prompt, enter RUN MYPROGRAM and hit enter, using your program name instead of "MYPROGRAM".
4. If you need to exit, hit RESET on the keyboard, you'll still be in DOS

If we are using a DOS master disk + a custom disk via 2 drives (option 2b)

1. Insert DOS 3.3 master disk in drive 1 (bootable). Allow to boot
2. Insert custom disk (image) in drive 2.
3. At the DOS command prompt, enter RUN MYPROGRAM,D2 and hit enter, using your program name instead of "MYPROGRAM". D2 specifies to look on the second disk.
4. If you need to exit, hit RESET on the keyboard, you'll still be in DOS