>What exactly does the kernel report for the Zip? What's the ID string
>and version, if any?

Incidentally, this machine is running 1.0, but I get similar (slightly
more verbose) messages on my -current box (~2 weeks ago).

It does make a difference if there is a cartridge in the drive at probe 
time, but not a lot. Essentially the Not Ready message goes away and the 
geometry returns non-zero numbers. Though, even with it detecting as below
it works perfectly.

Note, too, that my linux box makes no complaints whatsoever about the 
drive or any "illegal requests", which is why I suspected the netbsd scsi
code as just expecting too much; however, comparing netbsd apples to linux
oranges is probably an oversight of mine.

kernel messages:

aha0 at isa0 port 0x330-0x333 irq 11 drq 5
scsibus0 at aha0
aha0 targ 0 lun 0: <MAXTOR  LXT-340S        6.57> SCSI1 direct fixed
sd0 at scsibus0: 324MB, 1546 cyl, 7 head, 61 sec, 512 bytes/sec
aha0 targ 5 lun 0: <IOMEGA  ZIP 100         N*32> SCSI2 direct removable
sd1 at scsibus0sd1(aha0:5:0): illegal request
sd1: could not mode sense (4); using ficticious geometry
sd1(aha0:5:0): not ready
sd1: could not get size
: 0MB, 0 cyl, 64 head, 32 sec, 512 bytes/sec

and every time i mount a cartridge:

sd1(aha0:5:0): illegal request
sd1: could not mode sense (4); using ficticious geometry

Cheers,
Phil