73
But these needed the infamous TRS-80 expansion interface , which was very expensive , and had a very unreliable floppy disk controller because it used the WD1771 floppy disc controller chip without an external " data separator " .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 None