'TAD' (also known as TAD Corporation, pronounced as letters, 株式会社ティエィディ Kabushikigaisha TAD) was a Japanese game developer. It was founded by the former general sales manager of Data East USA, Tadashi Yokoyama, hence the company's namesake. Despite the company's limited lifespan, it created a few successful games. All of their games were exclusively arcade games, but a couple made it to home platforms including Cabal and Toki.
According to Akira Sakuma, TAD's arcade games all used a sound driver by Michiya Hirasawa. The music was written in the traditional way, in a custom Music Macro Language, possibly hexadecimal notation. Yukihiko Kitahara composed a majority of TAD's arcade games, but it is unknown if he used the sound driver himself, or if Hirasawa (or another developer) implemented his music into the sound driver.
In addition, the following text can be found in the audio code of Cabal, revealing the sound engine was outsourced from Seibu Kaihatsu:
Michel/Seibu sound 11/04/88
Michel was a known alias for Michiya Hirasawa.
Blood Bros., Heated Barrell, and Legionnaire also contain text in their audio code:
START UP PROGRAM V1.02 (C)1986 SEIBU KAIHATSU INC.