[geeks] SCA question

[Greg A. Woods]

[ On Wednesday, April 17, 2002 at 17:14:43 (-0400), Kurt Mosiejczuk wrote: ]
> Subject: Re: [geeks] SCA question
>
> Same here, I've got three IBM 18G LVD drives in (and hanging off of) my
> Ultra 1.  This is possible because part of the LVD spec is that the
> drives have to recognize when they are on a regular SE bus and adjust.

I don't think that's a requirement, but it's certainly an allowed
possibility.  Most such drives are identified as "LVD/SE".   I've heard
tell of LVD drives that don't do SE, at least not correctly enough to
live on a bus with other SE drives.

> The low-voltage part means that while they are busy realizing what's
> going on, the magic smoke doesn't get let out of the other drives and/or
> host adapter, as can happen with HVD =)

No, that's just due to the fact the 'L' stands for "low" and means about
1vdc, which isn't enough to smoke something normally expecting 5vdc.  :-) 

(as opposed the the 'H' standing for "high" and meaning +/- 12vdc, which
in one signal state means quite an unexpected voltage differential!)

-- 
								Greg A. Woods

+1 416 218-0098;  <gwoods at acm.org>;  <g.a.woods at ieee.org>;  <woods at robohack.ca>
Planix, Inc. <woods at planix.com>; VE3TCP; Secrets of the Weird <woods at weird.com>