12623
This relieved the mainboard and interface cards in the host computer of the chores of stepping the disk head arm , moving the head arm in and out , and so on , as had to be done with earlier ST-506 and ESDI hard drives .
 None
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 None