The Cellular Telephone Experimenters Kit, or CTEK, was designed in 1992 by Mark Lottor of Network Wizards. It was essentially an easy to use interface to the robust test mode of two models of cellular telephone: The OKI 900 and the OKI 1150.

The kit was amazingly popular for nearly 4 years among electronics enthusiasts, ham operators and other communications hobbyists, and phone hackers. Then OKI stopped making the phones, and Network Wizards stopped selling the cable. The source is still available for free on their site (, but without the cable it's just a piece of history, and not very useful.

There were three parts to the kit; console code, cable, and PIC code. The Turbo C source code, or compiled DOS binaries were the core of the kit. It allowed for the reprogramming of the telephone from a console, and the cable was the interface from the PC serial port to the phone. The PIC code was assembly language source that was fed to the phone itself to modify its program and allow for various on-the-fly modifications, such as tumbling ESN/MIN pairs.

Now resigned to a place in the history of telephony, the CTEK lives in memory as a reminder of the carefree days prior to the DMCA, before reverse engineering became an illegal practice.

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