The dollar generally firmed in very quiet trading on the world's money markets yesterday. The price of gold dropped more than $5 an ounce in both London and Zurich.

Foreign exchange dealers said the dollar was helped by remarks of U.S. Treasury Secretary Michael Blumenthal Thursday that the government plans further action to shore up the currency.

Late rates for the dollar in major European financial centers, compared to Thursday's late rates, were: Frankfurt, 1.9975 marks, up from 1.9909; Zurich, 1.6270 Swiss francs, up from 1.61775; Paris, 4.3707 francs, up from 4.3525; Milan, 835.05 litre, up from 834.60; Amsterdam, 2.1675 guilders, up from 2.1611. In London it took $1.93835 to buy a pound late yesterday, compared to $1.93425.

In Tokyo the dollar, which has been rising and falling between 189 and 192 yen the past five trading days, ended the week at 191.05 Japanese yen, up from 190.825 yen at Thursday's close.

In London gold closed at $205.75 an ounce, down $5.50 from Thursday's close of $211.25. In Zurich the metal ended the week at $205.625, a drop of $5.25 from $210.875 at the close Thursday.