The Littleton, Massachusetts-based minisupercomputer manufacturer Alliant Computer Systems Corp is having to take some drastic measures in a strenuous effort to restore itself to profitability. The company will reduce its workforce by about 75 people, 17%, in what it describes as a further consolidation of its Raster Technologies acquisition with its own operations. As a result, it will see a fourth quarter loss significantly larger than the $2.5m to $3m Wall Street had been expecting. It reported a loss of $8.7m for the first nine months of 1988 after an extraordinary gain of $3m on sales of $49.1m. On the up side, the company says its installed base rose to over 330 systems from 200 in the past year.