Combine sugar, water, and cream of tartar in a saucepan.
Stir over low heat until sugar is dissolved; increase heat and bring mixture to boiling.
Cover saucepan and boil mixture 5 minutes.
Uncover and continue cooking to 232°F (spins a 2-inch thread when dropped from a spoon); remove syrup from heat.
Beat egg yolks until very thick.
Beating constantly, gradually pour syrup in a very fine stream into egg yolks.
Cook mixture in top of double boiler over simmering water, stirring constantly, 8 to 10 minutes.
Cool over ice and water, beating constantly until mixture is cold.
Fold whipped cream into egg-yolk mixture.
Turn into 9x9x2 inch pan.
Freeze until partially frozen.
Remove from freezer; stir mixture until it is of even consistency.
Working quickly, drizzle partially thawed punch concentrate in small amounts onto ice cream; stir with a spoon or cut in with two knives to produce a rippled effect.
Return to freezer and freeze until firm, 2 to 3 hours.