The dollar soared against the the Japanese yen and was slightly higher against European currencies yesterday with attention again centered on the Iran. Gold was unchanged in Europe and lower in New York.

Gold closed in Zurich at $390 an ounce, the same as Thursday. In London gold rose 50 cents to $390.50, but it sold off at the close in New Ork, finishing up at $388 an ounce.

The dollr rose in Tokyo to near the 244-yen level at one point, but closed at 242 yen, up from 241.40 Thursday. In New York the dollar rose 243.35 yen.

In Frankfurt the dollar rose to 1.7945 West German marks from Thursday's close of 1.7925 marks; in Zurich to 1.64995 Swiss francs from 1.6447; in Paris to 4.20625 French francs from 4.2035; in Brussels to 29.64 Belgian francs from 29.575; in Amsterdam to 1.9940 guilders from 1.99; and in Milan to 830.30 lird from 829.45.

The British pound rose to $2.0920 from Thursday's $2.0850.

In New York the dollar remained firm, closing at 1.7945 German marks, 1.6515 Swiss francs, 29 Belgian francs, 1.9938 Dutch guilders, 4.2080 French francs, and 829.65 Italian lira. The pound rose to $2.0960. The Canadian dollar fell to .8402 U.S. cents from .8436 Thursday.