The eighth graders in Robert Reuter's confirmation class come early and stay late.

The attraction is a microcomputer named "R2D2" after the character in the movie "Star Wars."

R2D2 helps the pupils review lessons, tell Bible stories, teaches the Ten Commandments and creates religious symbols.

It also keeps the attendance records, records progress on lesson assignments and displays messages about coming event for young people.

Reuter started bringing the computer to his class at Calvary Lutheran Church in suburban Golden Valley three years ago. He uses it in his job.

The students bring their workbooks with them to class and discuss the merits of R2D2's answers (supplied by the church's minister) compared with theirs. If one of the questions calls for the drawing of a religious symbol such as a cross or menorah, the microcomputer obliges.

To help the 13- and 14-year-old students understand links between science and religion, Reuter shares with the class a newspaper story entitled "The mystery of the missing 24 hours."

The story, programmed into the computer and accomplished by a cassette recording, describes the confusion of a group of space scientists, unable to account for a 24-hour gap in elasped space time revealed by a complex computer calculation of the movement of plants over the past centuries. c

One of the scientist recalls a Sunday school lesson and locates biblical passages in Joshua and II Kings that offer a possible explanation of the missing time period.

R2D2 helps the students learn the Ten Commandments by providing a "catchword" sentence: "Our nifty rules help keep all sins behind chained cages." The first letter of each word is a reminder of each commandment. "O" is "our," for example, is a reminder that "Thou shall have no other gods before me," the First Commandment.

After the hint has been repeated several times by Reuter and the computer, the students take turns at the keyboard, trying to identify the commandent corresponding to each letter.

A word game that is a computer version of "hangman" is a favorite of the class. Blank spaces representing a word of the evening's lessons, words such as "eucharist," "absolution" and "covenants" appear on the screen, and the students divided into teams, shout out the letters that might fit the word. The computer automatically keeps the score as the blanks are filled and a clock in the computer allows 30 seconds for each word.

But Reuter brings R2D2 with him to class only about every third week. "It can be too much of a trap," he said.