When M. Alexander Stiffman, 39, an operations research analyst with the Department of Energy, moved into his home at 641 11th St. NW two months ago, he quickly decided he had to do something about the neighboring houses.

Adjacent to Stiffman's property was an abandoned house that fire had ravaged a year earlier, leaving trash, debris, closthes, lumber and bottles stacked several feet high in the backyard which Stiffman described as a "harbor for rats." Another neighbor's house also had trash, overgrown weeds and debris in the yard. Stiffman called that a "slum."

Stiffman said he called the approprate housing inspection in mid-September to complain about the two houses. Two days ago, after more than two months had passed with no improvements in the properties, Stiffman called again.

He said that he was told the properties had been inspected in late September, that the owners were located by Oct. 4 and that they were to be notified of housing code violations. But he was told, there was an additional foulup - computer problems.

Hundreds of building owners in District of Columbia who have been cited for code violations at their properties in the last two months have not been served notice requiring corrective action.

Abraham Greenstein, acting deputy administrator for the city's Department of Housing and Community Development, conceded yesterday that a backlog of "many weeks, almost two months" has occured because the department has not been able to use fully the computer that translates codes sheets filled out by inspectors. The computer in question is at the D.C. Department of Economic Development, Greenstein said.

Greenstein said he does not know how many notices have not been sent during recent months because of the computer backlog, but he said 32,000 such notices were sent last year - an average of almost 2,700 a month.

Greenstein said three problems have contributed to the backlog. He said that more staff members are needed at the Department of Economic Development and that when the computer was moved from the District Building to an office at 6th and G Streets NW in October, the computer had to be shut down for about two weeks.

In addition, Greenstein said, the Department of Economic Development handles licensing of city businesses and the licensing period for many firms begins Nov. 1.

"They (those seeking the printing of the licensee) get the priority," Greenstein said. He said the director of the city's housing department recently approved payment of overtime for economic development staff members and also the hiring of a worker for six months to operate the computer and reduce the backlog.

"We hope to catch up by the beginning of the year," Greenstein said. Economic Development Department officials could not be reached for comment yesterday.

Greenstein said his department has received an "accelerating" number of complaints in the last two weeks from people asking why code violations have not been enforced. He said he did not know exactly how many complaints have been received.

Greenstein said his office has served some violation notices by hand in emergency situations, such as those involving lack of heat and hot water or unsanitary conditions affecting health and safety.

"We try to pick out the most pressing problems and deal with them," Greenstein said. Other violations, such as peeling paint and deteriorating floors and ceilings, have not been dealt with, he said.

Similar problems have occured at this time of year in the past because of the licensing period, but the matter was made worse this year when the computer had to be shut down, Greenstein said. He said that the licensing year for several businesses may have to be changed to distributed the work load more evenly during the year.