Re: GS Crashing: copying files and Apple hi-speed SCSI (?)

[nraymond@k12.ucs.umass.edu (Nathan Raymond (Phillips Academy 94))]

In a previous article, crash!vmbb!pro-newton!pro-dan!danb (Dan Brown) says:
>In <32j5tl$n8v@eis.calstate.edu>
>gachenb@eis.calstate.edu (Greg R. Achenbach) writes:
>
>>1)  It seems that proper SCSI function depends on 3 things - termination, 
>>termination power, and magic.
>
>        Termination, term power, and good cables take care of 95% of the
>problems.  Voodoo is for the other 5%.
>
>>2)  The RamFast provides both termination and termination power.  The 
>>Apple HS SCSI provides termination, but not termination power.  The 
>>original Apple SCSI provides neither.
>
>        Mostly correct.  Some newer models of the HS SCSI do provide term
>power to their own terminators.  Unfortunately, there's no way to tell them
>apart.
>
>>3)  Drives vary in whether they provide termination, termination power, 
>>and how much magic is necessary to get them to run.
>
>        Mostly true.  Most drives have a place to mount terminators on the
>drive itself.  To tell if terminators are present, on most drives, look for
>three ~7/8" long resistor packs, end to end, right near the 50-pin header at
>the back of the drive.
>
>        If I can figure out how to do it, I'll try to upload a GIF to c.b.a2
>tomorrow explaining how to modify the Apple II SCSI Cards to supply term
>power.  I'll also look for info on how to mod the drives.  You run a diode
>from the +5v source to pin 25 or 26 on the header, but I don't remember what
>kind of diode.

I don't know if anybody has tried (or heard of) this yet, but APS
technologies (well known and respected Mac hard drive company) makes a
product called SCSI Sentry, which is shaped like a big terminator with
lights.  It provides digital active termination, "monitoring all SCSI data
and handshaking lines, constantly matching impendance and regulating power." 
The lights indicate chain activity and tell you if there is enough
termination power, and it includes a power supply you can plug into SCSI
Sentry to supply termination power if you need it.  I don't work for APS or
anything, I'm just a happy owner of their products (I personally haven't
tried SCSI Sentry because I've never needed it, but it got good reviews in
MacWorld this month).  This terminator carries a BIG pricetag, though - $99. 
But for those without the skill to fiddle with the inards of a SCSI device,
this provides another alternative, and besides, it claims to "stop SCSI
Voodoo."  :-) APS can be reached at 1-800-723-2994 (I might also add they have
good tech support).

nathan
nraymond@genesis.nred.ma.us
-- 
"We don't know one millionth of one percent about anything."
- Thomas Alva Edison