24 Feb
2009
24 Feb
'09
6 p.m.
The thickness of the lamination moves the magnetic
medium away from
the
head,
reducing signal strength or S/N and maximum possible bit density.
I don't know what the density is on DECtapes but I presume it was
fairly low
and they could get away with the lamination, or they traded off bit
density for robustness.
Bitsavers has assorted DECtape documents, including a spec of the media.
It says the coating is 0.04 mil thick, so the magnetic media don't move
away much.
Density is quoted as 375 dpi, give or take, in a 1964 article also on
Bitsavers.
paul