Apple IIGS and C development environment

This document is meant to show how to configure an Apple IIGS emulator to run Apple GS/OS and then to install the software to do C software development. While there are several emulators available, I use GSplus Emulator.

There are several important parts to a working emulator setup. They are:

  1. GSplus application
  2. Apple IIGS ROMs
  3. Apple IIGS disk image
  4. ORCA Compiler Suite / OPUS II

GSplus

Download the latest version of GSplus from GSplus Emulator. I’m on Windows, so I downloaded the zip file.

GSPlus zip file contents

Extract the contents to your hard drive. I suggest using a folder called gsplus to hold the contents of the zip file.

ROMs

Next you will need ROM and hard disk images for GSPlus. They can be found at What is the IIGS?. I’ve been able to use ROM1 and ROM3 without problems.

GSPlus ROM Selection

ORCA Compiler Suite / OPUS II

ORCA C is available from Juiced.GS. Byteworks sells all of their software as Opus II, including the C compiler.

After buying the compiler suite, download the ZIP file for the compiler and extract the contents. The Byteworks.po file is in “The Software\For Emulators”.

In the GSPlus emulator, mount the Byteworks.po disk image.

Byteworks disk image

When you mount the disk image, you might be tempted to use s5d1, s5d2, s6d1, or s6d2. Those are for floppy images. Use one of the s7 drives as shown in the screenshot. Mounting the Byteworks.po file as a floppy will cause errors.

Launching the destop environment

Byteworks ORCA folder

Open the ORCA folder. This is where the desktop environment can be launched. The launcher is called ORCA.Sys16.

Desktop Environment Launcher with arrow

Double-click on the ORCA.Sys16 icon to launch the desktop environment.

Prism

The environment shown here is called prism. Prism is able to call the other programs in the toolchain to carry out their functions.
An editor is included, as well as a compiler, assembler, and linker.

ORCA Desktop Environment