Four months after the signing of the Salisbury agreement ushering in the current biracial transitional government, white-minority rule is still alive and well in Rhodesia even though its days may be numbered.

The addition of three moderate African nationalist leaders and nine African ministers to the government has made no significant difference in the way things are run - although the confidence of both Europeans and Africans in the future of such rule probably has been shaken.

Ian Smith is still very much the prime minister and his Rhodesian

Front, holding all 50 white seats in the 66-member lower house of Parliament, still very much the ruling party.

To all appearances, white ministers and civil servants hovering around their black counterparts make all important decisions. The conduct of the war has been kept in the hands of white officers. And the white half of the government has successfully blocked any attempt by the black half to force through any meaningful change in the status quo. The one black minister who spoke out for some "adjustments" was fired within days of his outburst in April.

White control even extends to censoring what the African parties - whose leaders are members of the transitional government's Executive Council - say about military or related sensitive matters.

Asked to give examples of how the blacks were epecting power in the new government, the press spokesman for its leading African nationalist, Bishop Abel Muzorewa, offered just two reducting of the curfew in one African reserve from 22 to 12 hours a day, and the opening of a few "protected villages" to allow Africans to come and go as they wish.

Ironically, the most forceful use of black power with the new government has been to block Smith from accepting the British-American call for it to attend a general peace conference with the guerrillas.

(He might also have added, but did not, the release of hundreds of political detainees and the lifting of the ban on two political parties, one of them dead set against the March transitional agreement and deeply involved in the guerrilla war).

The impression of most blacks and whites, as reflected in a general debate in Parliament two weeks ago, seems to be that the present government is deadlocked, unable to strike out forcefully because it is paralyzed racially.

The new government is akin to "a sled being pulled by four hours all going to different directions," said one white farmer, referring to Smith and the three black leaders who are theoretically supposed to share power with him.

From the beginning, the transitional government has been caught in a cross-fire between jittery whites seeking reassurance that no significant changes will come in their comfortable colonial style of living and an African population expecting to see the dawn of a new era.

Over the past four months, both population have been either frightened, embittered or deeply disappointed in their expectations by each other's demands and words. Whites seem to be holding on for dear life to the power and privileges they know they are expected to surrender at the end of this year, while blacks are building up enormous resentment and frustration at the slow pace of change.

Part of the problem is that neither white or black leaders of the transitional government have done what was expected of them. "The nationalist leaders said they could deliver the goods. Well, let them deliver," said an angry and disappointed white member of Parliament.

The black deputies expressed the same sentiment, not only about the African leaders but about the whole transitional government.

When the agreement was signed March 3. Smith expected that the three nationalist leaders he had negotiated with, particulary Bishop Muzorewa and the Rev. Ndabaningi Sithold, would swing enough weight with nationalist guerrillas to bring about a cease-fire.

The African nationalists, in turn, expected Smith to convince the British and Americans to support the transitional go ernment and quietly campaign for the lifting of U.N. imposed economic sanctions.

But neither a cease-fire, Western recognition or a lifting of sanctions has occurred. Barring victory by the Conservative Party in expected elections this fall, there seems little likelihood of any change in British policy toward its rebel colony.

Meanwhile, the performance of the transitional government has won no kudos from either the black or white population at home. In the first place, it was slow to take off. Instead of first selling the agreement to his own people. Bishop Muzorewa flew off the very day it was signed to London and Washington to convince the West of its merits.

He did not return for two weeks and it was not until March 22 that the Executive Council was formally established. It took another two weeks to choose nine white and nine black men to serve as coministers in the new biracial Cabinet. Smith, worried about a white backlash, kept his hardliners as if to assure that no upsetting changes would come about.

By mid-April, the government was finally launched. Within days it was deep in crisis over the firing of the black cominister of justice. Byron Hove, who had called for "positive discrimination" in favor of Africans in promotions within the civil service and police force.

Hove left the country in a whirl of controversy, saying what most blacks suspected all along, that Smith and his party were "trying to cheat us, to take us for a ride" on power sharing.

Muzorewa, who had chosen Hove, first publicly stated that he had agreed to his dismissal. To make up for it, he has boycotted ever since all public appearance with his black and white Executive Council colleagues. His party, the United African National Council, nearly voted to pull out of the government.

The Hove affair dealt a devastating blow to the credibility of the March agreement among blacks while stirring the worst fears among whites for their future under black rule. Last week in Parliament, one while senator said the repeated African use of such words as "Africanization" and "discrimination" was discouraging whites from staying on after the blacks take over.

In early May, the government sought to recoup its losses from the Hove incident first by lifting the ban on activities by two African parties, one of which Sithole claims to lead rather than the guerrilla leader Robert Mugabe, and then by calling for a unilateral cease-fire by the two guerrilla groups. It also release nearly 500 political detaines but kept at least 230, and possibly as many 500, others in jail.

The call for a ceasefire, meanwhile, went largely unheeded despite Sithole's much vaunted influence with the guerrillas as one of their early leaders.