:According to 1986 Disk/Trend, in 1984 two sided 3½ was 35% of about a 2.0M unit market. 1983 was a 400k total market, mostly one sided, but the 1984 two sided at ~700k was almost double the total 1983 one sided.  It sounds to me like a lot of two sided availability in 1984 and I will revise the edit to reflect this.  See what u think.