To Sixtoe:

I looked at Thundercade in the Toaplan section, and you were wrong.

Thundercade is developed by Seta, not Toaplan, and the game runs on an eariler version of the Seta hardware (you're right about the sound hardware, but later games [Twin Eagle] use the Seta X1-010 sound chip clocked at 16 MHz).

Hope this info will be useful for your next update!