Subject: ZIP Drive problems
To: None <>
From: Mike Sienicki <>
List: port-atari
Date: 11/17/1998 21:22:21
All Atari/NetBSD would-be ZIP drive users,

I am writing this information to anyone attempting to get a ZIP 100 drive
up and running on the TT030 (and this probably applies to all others using
SCSI as well) since it might save Leo (and others) the time of having to
repeat what he has already explained to me in getting the ZIP drive going.
Some of the following are quotes from Leo.

Step #1  Don't be a SCSI Scuzball! (like I was)  8^(  The most important
thing and the weakest link in the system just may be the SCSI buss!!!  "But
the SCSI buss sees the ZIP drive just fine and I can read and write to the
drive ''to a point'', and besides, I have ran several hard drives in place
of the ZIP drive without any problems unterminated and on a short length of
SCSI cable connected to the back of the TT's port" (thinking that a short
cable "stub" wouldn't cause excessive ringing or reflections of the signals
without termination).  Don't be sucked in by this thinking or you'll pull
out some hair trying to figure out what's wrong with software when the real
problem is hardware configuration!  I know the rules of SCSI and I tried to
get away with murder on the buss and the cops stopped me!  Here is a quote
from Leo to me:

>There seems to be a bit of a fight between the scsi-driver and the ZIP.
>A few things of interest:
> [....]
>  - are you absolutely sure that your scsi-termination is correct? In
>    your case, the IBM (hard drive) & IOMEGA should be terminated and the
>internal TT-resistors removed.

Yeah Leo, FIGHT was the right word!  8^)  After pulling out what little
hair I had left, I took his advice to heart and yanked the TT's internal
resistor networks and terminated the external Iomega ZIP drive (my internal
hard drive was already terminated).  To my amazement, after doing another
"newfs -i 16384 /dev/rsd1c" it came back with no errors and was able to
mount it as another device!  8^)

Step #2  If you still have problems with errors on the SCSI buss be aware
that not all SCSI cables are made alike.  Some cables look like printer
cables and unless they are very short, stay away from them.  If they are
not of the twisted pair variety they are probably loaded with lots and lots
of picofarads of capacitance between signal lines and will therefore cause
crosstalk and ringing of the signals.

Step #3  On V1.3H (or possibly other kernel versions), you may want to edit
the scsiconf.c file to get rid of junk lun's.  Again, here is a quote from

>Ah, problem number one! Apply the diff below (to scsiconf.c).
>--- /usr/src/sys/dev/scsipi/scsiconf.c	Tue Sep  8 13:10:47 1998
>+++ ./scsiconf.c	Thu Nov 12 11:39:26 1998
>@@ -495,7 +495,7 @@
> 	 "iomega", "jaz 1GB", 		 ""},	  SDEV_NOMODESENSE},
>-	 "IOMEGA", "ZIP 100",		 ""},	  SDEV_NOMODESENSE},
> 	/* Letting the motor run kills floppy drives and disks quite fast. */
> 	 "TEAC", "FC-1",		 ""},	  SDEV_NOSTARTUNIT},

Or simply put (to make the above change easier to understand for us
illiterate types) just add  "|SDEV_NOLUNS" after "SDEV_NOMODESENSE" in the
line with the ZIP 100 in it using vi or other text editor.

Step #4  If you see a line in your bootup messages that looks like this:
         "sd1(ncrscsi0:1:0): Does not support linked commands"
then take the advice of an expert and:

>This might be another pitfall... Try setting TRY_SCSI_LINKED_COMMANDS to
>0x7d (ie. disable _all_ linked commands for target 1).

The option Leo mentioned above is located in _some_ of the kernel build
source files in:
Note that the 0x7d also mentioned is an hexadecimal number and will be
different depending on what the SCSI target ID of your zip drive is for
example:  (I hope I'm right on this)
ID #0 --> 0x7e
ID #1 --> 0x7d
ID #2 --> 0x7b
ID #3 --> 0x77
ID #4 --> 0x6f
ID #5 --> 0x5f - Default ZIP Drive setting as shipped.
ID #6 --> 0x3f

Changing this will require building a new kernel and you can find info on
doing this in the FAQ file in the atari section of the website.
Also be aware of the fact that some of the above mentioned changes may only
be required for V1.3H to get the ZIP drive to work.

Step #5  Have fun with the ZIP drive.

--Video Mike--