Systems Center Inc, formerly VM Software, which made its living entirely out of IBM users until it signed with Tandem Computers Inc to do versions of its newly-acquired Net/Master network management software a few weeks back, has taken a big step towards diversification with agreement to acquire Reston neighbour Unitech Software Inc, which specialises in Unix system utilities and Unix network administration software. Unitech, whose leading product is Backup.Unet for backing up Unix networks, does over half its $1.5m annual turnover with the US Federal government. Systems Center is to acquire Unitech in an exchange of shares valuing the target at between $4.5m and $6.8m, with closing expected in the fourth quarter. Unitech has $1.5m sales for the year to May 31 1990 but is looking for $3m in calendar 1990.