Sorry, I couldn't find pricing data for that day. The closing price for Microsoft (MSFT) on August 29, 1986 was $0.06. It was down 2.6% for the day. The latest price is $511.23.
DATE
OPEN
HIGH
LOW
CLOSE
VOLUME
August 29 1986
$0.06
$0.06
$0.06
$0.06
25,430,400
Daily pricing data for Microsoft dates back to 3/13/1986, and may be incomplete.