is this past or present tense

Mi Papa escribio un cheque

Past, but there should be an accent on the o.

http://www.dummies.com/how-to/content/conjugating-the-spanish-verb-escribir-to-write.html

Mi papá escribió un cheque. Papá with accent on the a, otherwise it means potato

Mi papá escribió un cheque

The sentence "Mi Papa escribio un cheque" is written in the past tense. The verb "escribio" is the past tense form of the verb "escribir," which means "to write." In Spanish, the use of past tense can indicate that the action or event being described happened in the past. In this case, it means "My dad wrote a check."