Color Inspector is an Apple II program written in 6502 assembly that displays a single screen showing the sixteen available colors along with their names and numbers and the chrominance (phase and amplitude) and luma values the hardware uses to achieve them in the composite video signal. It can be used to verify that a monitor or emulator is producing accurate colors and that an emulator implements various aspects of the Apple II architecture correctly.

Compatibility

Color Inspector uses the vaporlock technique to detect the start of each video frame and switches between text and graphics modes during each frame, so it requires a real Apple II computer or an emulator that implements instruction timing, the floating bus, and intraframe mode switches correctly.

It requires exact timing so on the IIɢs or other machines with accelerators you must set the machine to 1 MHz first.

Real hardware

Color Inspector has only been tested on an Apple //e but the following models should be compatible:

• Apple ][, Apple ][ plus
• Apple //e, enhanced Apple //e, platinum Apple IIe
• Apple //c
• Apple IIɢs

The following models are not currently compatible:

• Apple ][ europlus and PAL versions of Apple //e (different video timing)
• Apple //c plus (different ROM WAIT routine timing)
• Apple ///, Apple /// plus, Apple IIe Card for Macintosh (no floating bus)

Expect problems with clones too.

Emulators

The following emulators are compatible:

• Clock Signal (2023-11-14 and newer)
• MAME

The following emulators are not currently compatible:

• OpenEmulator
• Virtual ][

Building

To build Color Inspector, install cc65 and run:

make

To make a disk image that can be loaded into an emulator or transferred to a real floppy disk using adtpro, install c2d and run:

make dsk

To make an audio file that can be played into a real Apple II, install c2t and run:

make aif

To play that audio file into a real Apple II on macOS, connect an audio cable between your Mac's audio out port and the cassette in port of an Apple ][ plus, Apple //e, enhanced Apple //e, or platinum Apple IIe, and on the Apple II run:

LOAD

and on the Mac run:

make play

License

Color Inspector is released under the MIT license. It uses vaporlock and a routine to print decimal numbers, each of which are under different licenses. See the LICENSES directory for the full license texts.