🚀 go-pugleaf

Ted Rypma (rypma@waterloo.hp.com) wrote:

: [Tried a question about jumpers earlier, no answers, so try again :-]

: I recently put my original 163 Mb PMac 6100 internal drive into an
: external box. It works fine there UNLESS I POWER IT DOWN. If I leave
: the SCSI cable connected to the external box, without power to the
: drives there, the bus hangs on start-up. If I power up OR remove the
: IBM drive from the chain (there are three drives in the external box)
: things work fine. [The IBM drive ID's itself as "H3171-S2".]

: I have all the external drive terminators removed, and use an external
: terminator. The IBM (which is SCSI 1) has a single jumper which
: supposedly removes its internal termination resistors (at least the
: sightly newer IBM drives work that way - I never did find the diagram
: for the exact drive I have). The internal drive is terminated.

Unfortunately, I have no solution or explanation - I can only report that 
the exact same problem also crops up with a Toshiba 5301B CD-ROM drive: 
when it is powered down, it hangs the bus. There is nothing I could do 
about it; neither the state of internal/external termination nor the 
cabling did anything about it. It seems that some SCSI drives do funny 
things to the bus when they are powered down, ie they do not act 
electrically passive in that state. Still looking for explanations.

Peter

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/ Peter Schneider              []  Englisches Seminar         \
| E-Mail: pschneid@es.unizh.ch []  Universitaet Zurich        |
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