Question: what is the maximum amount of ram that the original pc processor could access
[{'answer': '640 KB', 'provenance': [{'wikipedia_id': '420215', 'title': 'Conventional memory', 'start_paragraph_id': 2, 'start_character': 11, 'end_paragraph_id': 2, 'end_character': 17, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '420215', 'title': 'Conventional memory', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 208, 'bleu_score': 0.950578622812921, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8730884166378280993}, 'section': 'Section::::640 KB barrier.\n'}]}]