Positron User's Guide: Installation

The only prerequisites for running positron are a UNIX-like operating system that supports USB Mass Storage devices and Python 2.2.1 or later. These directions focus specifically on Linux, though positron is certainly not Linux-specific. (Warning to the adventurous: positron should work on MacOS X, however a USB bug on the Neuros makes it appear as a read-only device on OS X. Hopefully a fix will be available soon.)

If you do not have Python 2.2.1 installed on your system, you should install it before continuing. You can get Python from the Python website, but all modern Linux distributions package it, so you should look for one of those packages first.

There are three parts to installing positron: setting up the kernel for USB, making the Neuros mountable, and installing the positron software itself.

Setting up the Kernel

The Neuros requires no custom drivers because it interfaces with the computer using the USB Mass Storage standard used by USB hard disks and other storage devices. If you already have Linux setup to do this, you can skip to the next section.

First make sure you are using a Linux 2.4 kernel. It appears that the reliability of USB Mass Storage in the 2.4 series has varied quite a bit, so using the newest kernel you can is suggested. Kernels 2.4.20 and later have been reported to work well on several platforms, though your milage may vary.

The next thing to check is that you have the required kernel modules.

usbcore - This is required for any USB device.
usb-uhci/usb-ohci - One of these is used depending upon your USB host controller
usb-storage - For using USB Mass Storage devices
scsi_mod and sd_mod - USB Mass Storage devices show up as SCSI disks, so you'll need SCSI support.

Nearly all current Linux distributions come with these modules precompiled and many automatically load some or all of them for you. If you need to load them manually, you can use

modprobe [name of module]

to load a module once, or edit /etc/modules or /etc/modules.conf to have the module automatically loaded for you. If you find that you are missing one or more of these modules, you will have to recompile kernel to get them. Kernel compilation is beyond the scope of this document, but you can read the Kernel HOWTO for more information.

Making the Neuros Mountable

Now that you have all the kernel modules loaded, you can plug your Neuros into your computer using the USB cable that came with it. Within a couple seconds, the kernel will recognize the device and (if all goes well) assign it a SCSI device. Run

dmesg

as the root user, and you should see messages that look like this:

hub.c: new USB device 10:18.0-1, assigned address 2
scsi1 : SCSI emulation for USB Mass Storage devices
  Vendor: NEUROS    Model: dig. audio comp.  Rev: 1.00
  Type:   Direct-Access                      ANSI SCSI revision: 02
Attached scsi removable disk sda at scsi1, channel 0, id 0, lun 0
SCSI device sda: 39070048 512-byte hdwr sectors (20004 MB)
sda: test WP failed, assume Write Enabled
 /dev/scsi/host1/bus0/target0/lun0: p1
WARNING: USB Mass Storage data integrity not assured
USB Mass Storage device found at 2

The line that says "SCSI device sda" tells you that device name Linux assigned to your Neuros is /dev/sda. The Neuros has only one partition, so you will be mounting /dev/sda1.

Next, make the directory /mnt/neuros. (Of course, you can name this whatever you like, just be consistent through the remainder of the directons.) Edit /etc/fstab and add the following line:

/dev/sda1 /mnt/neuros vfat user,noauto,umask=0    0 0

This will permit normal users to mount and access the Neuros, so you won't have to use positron as the root user.

Finally, login as a normal user and mount the Neuros:

mount /mnt/neuros

You should be able to change to the /mnt/neuros directory and list the contents. There should already be files and directories on your Neuros, even if you just bought it. Note that these directions are the same regardless of whether you have a 128 MB or 20 GB Neuros (although the storage capacity shown by the kernel above will vary).

Before you unplug your Neuros, make sure to unmount it:

umount /mnt/neuros

Installing the Positron Software

The hard part is over! Now you just have to install positron itself, if you have not done so already. The method you use will depend on your setup.

RPM Based Distributions (RedHat, Mandrake)

Download the latest positron RPM from the positron homepage. (Note: you do not need the Source RPM.) As the root user run:

rpm -Uvh positron*.rpm

This will also upgrade your current version of positron if you already have an older version installed.

DEB Based Distributions (Debian, Knoppix, etc.)

Add the following lines to your /etc/apt/source.list

deb http://i.cantcode.com/~jack/debian unstable main contrib
deb-src http://i.cantcode.com/~jack/debian unstable main contrib

Then type:

apt-get update
apt-get install positron

You can rerun this later to upgrade to a newer version of positron.

Gentoo

There is an ebuild for positron. To install type:

emerge positron

and it should download the source and install it for you.

Installing from Source

If for some reason one of the above methods do not apply to you, or you just want to install positron from source, download the source tarball from the positron homepage. Untar the tarball and cd to the positron source directory. If you want to install positron to the default location of the /usr directory, run the following as the root user:

python setup.py install

If you want to install to a different prefix (like /usr/local), run

python setup.py install --prefix=/some/prefix

or:

python setup.py install --home=/some/prefix

Please see "Installing Python Modules" at http://www.python.org/doc/current/inst/inst.html for more information on how to use python distutils.