2 Jun
2018
2 Jun
'18
11:26 a.m.
List:
This is one that's bothered me for most of my adult life. As you may or
may not know, there were three industry standard densities for 7 track
1/2" tape: 200, 556 and finally 800 cpi/bpi.
So 200 and 800 are nice decimal multiples of 10. But 556 doesn't fit
that pattern--it's not a "nice' number, being the product of 4 and 139
and doesn't correspond to any computer-related characteristics that I
know of. It's not metric. So why 556 and not 400, 512 or 600?
There's got to be a story there, somewhere. I think the 556 density
came in around the 1401/7090 time with the 729 II.
Anyone know the story?
--Chuck