13 May
2009
13 May
'09
3:46 a.m.
I wrote:
Does anyone have a copy of the SMD-E Interface
Specification, which is
CDC/Imprimis/Seagate document 64712402? The spec for the earlier SMD
interface is on Bitsavers, but it doesn't look like the SMD-E spec is
there.
Al Kossow wrote:
I made a table of the differences, but I can't
find it right now. You can
deduce it by looking at the extra tag bits on the faster drives.
Are there not
electrical differences? Some SMD-E drives have transfer
rates of 24 Mbps, and I'm dubious that the SN75110 drivers and
SN75107/108 receivers that were specified in the original SMD spec are
suitable for data rates that high (judging by their worst-case
propagation delay spec).
And watch out for E-SMD vs SMD-E.
What's
E-SMD?
And for that matter, what is SMD-O? Some drives, like the Seagate
Elite, claim to be compatible with SMD-O and SMD-E.
Eric