3.6 KiB

Generic Tile Engine for the Apple IIgs

A high-performance library for writing tile-based games for the Apple IIgs personal computer in 65816 assembly langugage. Unlock the full, 16-bit potential of the last machine of the Apple ][ line.


The Generic Tile Engine (GTE) project is a tile engine built to exploit the unique hardware capabilities of the Apple IIgs personal computer. It supports the Apple IIgs super hires graphics mode (320x200, 16/256 colors) and provides two full-screen independent scrolling layers along with software sprites. The API and core functionality of the library is inspired by the graphics hardware of the NES/SMS/SNES/Genesis console era.

An overview of GTE was presented at KansasFest 2022.

Parallax scrolling of two full-screen static layers

Building from Source

The library iscurrently implemented as a set of source files that must be compiled into a GS/OS application. A set of example project can be found under the demos folder. Each demo folder uses a package.json file to define the build targets and a build of each application can be created by executing a npm run build command.

Each demo application has a build script that also builds the toolset and copies it, along with the demo S16 application file, to the target disk image.


  • node
  • merlin32 (1.1.10+)
  • cadius

GTE uses the merlin32 1.1.10 assembler to compile its source into GS/OS OMF files and Cadius to copy those files onto a ProDOS disk image. The paths to these tool can be set in the package.json file.

An empty 2MG disk image is included in emu/Target.2mg and is used as the default location for copying demo applications. This image can be mounted in any IIgs emulator.

Build of demo app in the IIgs Finder


Please refer to the GTE Toolbox documentation.