 A micro-controller version with a slightly modified instruction set, the 6811, was discontinued as late as the second decade of the 21st century.The Hitachi 6309 was an enhanced version of the 6809 with extra registers and additional instructions, including block move, additional multiply instructions and hardware-implemented division.It was used in unofficially-upgraded Tandy Color Computer 3 computers and a version of OS-9 was written to take advantages of the 6309's extra features