Digital Switch Corp. says that it has registered up to 604,662 shares of common stock that could go to holders of options, warrants and convertible debentures.

Most of these were acquired by creditors to the company between late 1979 and early 1982 in return for loans. The options can be exercised by the holders at a cost of $3 or $5 a share. If all the warrants or options are exercised, the company says it will collect about $1.5 million.

The company says it already has received $4.5 million from the exercise of warrants covering about 905,000 shares. These warrants were part of a public stock offering in 1980.

Formerly based in Reston, the high-tech company moved to suburban Dallas about a year ago. For about five years, the company has existed on the promise that it was developing a high-speed, compact electronic device for routing telephone calls.

In the past year, Digital has developed a prototype and has begun shipping production units, and has orders from four customers, according to Richard Scroggins, Digital Switch's vice president for finance.

As a result, Digital recorded its first sales -- $3.5 million -- and $274,000 in profits during the second quarter.