Operating instructions
SEA M300USERSGUIDE
GENERALINFORMATION
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2. Use the seadrive -qnx to mount the ‘/hd1’ directory, which is the mount point to for the USB
drive.
3. Copy the files.
4. Before removing the USB drive, use seadrive -qnx to un-mount the drive.
5. Remove USB drive.
Using a USB drive with a Windows FAT.
1. Insert USB drive. These steps assume we are only using one drive and it’s the only one mounted.
2. Use the seadrive to mount the ‘/dos/c’ directory, which is the mount point to for the USB
drive.
3. Copy the files.
4. Before removing the USB drive, use seadrive to un-mount the drive.
5. Remove USB drive.
USINGTHECDROM/DVDROMDRIVE
There are multiple ways to access the CDROM/DVDROM drive but for your convenience our
engineers have included the mounting of the drive in the system initialization file (sysinit) located in
your /etc/config directory. The file system is not QNX or DOS but rather the cdrom standard
ISO9660. SEA configures your CDROM mount point to be /cd0 by implementing it when the
system starts using the command Iso9660fsys >/dev/null2>&1& in your sysinit file. You may
encounter problems with accessing the drive if you have previously attempted to mount the drive
manually because it has already been mounted. Restarting your system will restore the proper mount
point. To access the CDROM/DVDROM drive (DVD support required a DVDROM drive):
1. Access the drive by typing cd /cd0 in a shell.
2. Then type ls to view the contents of the CD/DVD.
TIMESYNCHRONIZATION
As far as time synchronization goes there are several aspects to consider.
• QNX 4 keeps track of time in seconds and nano seconds (since January 1st, 1970). PC clocks are not
accurate and drift considerably over time.
• M300 also keeps track of time in seconds and nano seconds (similar to QNX 4). These are incremented in
the IRQ 3 handler to keep track of time internally.
• System/SBUS Interface temperature controlled crystal (is highly desirable). Accuracy of 2 ppm, +/- 0.1728
sec/day.
• System/SBUS Interface with standard crystal accuracy of 100 ppm, +/- 8.64 sec/day. Not recommended
(use System/SBUS Interface temperature controlled crystal).
• PC Clock/QNX 4 clock typical accuracy of 30 ppm, +/- 2.592 sec/day.