He was in the Juice crew. Had an album out in '90
Take a Look Around produced by Marley Marl. Dropped 2 albums
SlaughtaHouse ('93) and
Sittin' on Chrome ('95) with his group Masta Ace Incorporated.
In '01 he dropped
Disposable Arts, which told a story. In '04 he dropped
A Long Hot Summer which is a prequel to DA (prologue like Toopack said).
He did say he retired though:
http://www.allhiphop.com/hiphopnews/?ID=3355
Afterwards he said
"People have been throwing around the word retirement," sniffs Ace from his Brooklyn home, "but I'd call it more of a career adjustment. I'm really just changing my focus and expanding on what I do.
...
He intends to continue touring behind A Long Hot Summer for the rest of 2005, and while he has no immediate plans to return to the studio, he hasn't discounted the possibility of guest cameo appearances or performances at one-off events.
"I'm still down for collaborations. Actually, I just did a track with your boy Serious for his new album and I'll still keep writing rhymes – that's never gonna stop."
http://www.nowtoronto.com/issues/2005-01-27/music_vibes2.php