NTDEC was Whirlwind Manu or they were really close to each others. I think W.M. disappeared when Nintendo sued NTDEC in 1993. But I could be wrong. There carts were sold in many many countries, for exemples: South Korea, South America, Europe, USA (for a short time), Russia, maybe Thailand and China. The board quality is random, sometimes it's well built with PROMs/EPROMs, other time it's cheap globtops.