user manual

Debugger General Information
3-4 Installation Guide
3
Note that the MVME197LE also contains a parallel port. To use a parallel
device, such as a printer, with the MVME197LE, connect it to the “printer”
port at P2 through an MVME712X transition module. Refer to the
MVME197LE, MVME197DP, and MVME197SP Single Board Computers
Programmer’s Reference Guide for some possible connection diagrams.
However, you could also use a module such as the MVME335 for a parallel
port connection.
5. Power up the system. 197Bug executes some self-checks and displays the
debugger prompt “197-Bug>” (if 197Bug is in Board Mode). However, if
the ENV command has put 197Bug in System Mode, the system performs
a self test and tries to autoboot. Refer to the ENV and MENU commands.
They are listed in Table 4-1.
If the confidence test fails, the test is aborted when the first fault is
encountered. If possible, an appropriate message is displayed, and control
then returns to the menu.
Autoboot
Autoboot is a software routine that is contained in the 197Bug to provide an
independent mechanism for booting an operating system. This autoboot
routine automatically scans for controllers and devices in a specified sequence
until a valid bootable device containing a boot media is found or the list is
exhausted. If a valid bootable device is found, a boot from that device is
started. The controller scanning sequence goes from the lowest controller
Logical Unit Number (LUN) detected to the highest LUN detected. (Refer to
Appendix B for default LUNs).
At power-up, Autoboot is enabled, and providing the drive and controller
numbers encountered are valid, the following message is displayed upon the
system console:
“Autoboot in progress... To abort hit <BREAK>”
Following this message there is approximately a thirty-second delay while the
debug firmware waits for the various controllers and drives to come up to
speed. Then the actual I/O is begun: the program pointed to within the
volume ID of the media specified is loaded into RAM and control passed to it.
If, however, during this time the user wants to gain control without Autoboot,
the <BREAK> key or the software ABORT or RESET switches can be pressed.
Autoboot is controlled by parameters contained in the ENV command. These
parameters allow the selection of specific boot devices and files, and allow
programming of the Boot delay. Refer to the ENV command in Appendix A for
more details.