Lotus unveiled its Signal stock-quotation device.

The Cambridge, Mass.-based computer software company, diversifying to escape its dependence on the popular software program 1-2-3, said buyers of Signal will be able to get financial information through a unique radio receiver and store it in a personal computer. Signal will cost $595 plus a monthly subscription fee of $125, which Lotus said is about one-fifth what it costs to get such information over leased telephone lines. The company said it will start shipping Signal on Oct. 1.