Question: who did microsoft strike a deal with to provide dos operating system
[{'answer': 'IBM', 'provenance': [{'wikipedia_id': '4240094', 'title': 'History of Microsoft', 'start_paragraph_id': 2, 'start_character': 45, 'end_paragraph_id': 2, 'end_character': 48, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '4240094', 'title': 'History of Microsoft', 'start_paragraph_id': 14, 'start_character': 36, 'end_paragraph_id': 14, 'end_character': 1178, 'bleu_score': 0.916617394469534, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4326285138654230237}, 'section': 'Section::::1975–1985: The founding of Microsoft.\n'}]}]