AT&T 3B2/300 Technical Reference Manual page 335

FUNCTIONAL D E S C R I P T I O N - - - - - - - - - - - - - - - - - - - - - - - - - - -
System Board Firmware
The system board firmware is programmed instructions stored in Read Only Memory (ROM) which
form the basic operating system when the system is not running the UNIX operating system. The
purpose of this firmware is to initialize the system and provide the means to load and run other
programs such as the UNIX operating system, filledt, and dgmon. The firmware level built-in
programs are listed below:
baud Change the firmware baud rate. Valid firmware baud rates are 50, 75, 110, 134,
150, 200, 300, 600, 1200, 1800, 2400, 4800, 9600, and 38400. The default baud
rate is 9600.
edt
error info
newkey
passwd
sysdump
version
Display the Equipped Device Table (EDT) data.
Display expanded firmware error message information. This capability is provided
with firmware PF3 and later versions. (Command is intentionally omitted from
firmware command menu.)
Make a new floppy key.
Change the firmware password.
Copy the system image (RAM) to floppy disks.
Display firmware version information.
When the system is RESET or first powered on, the system board firmware controls the
initialization of the system. The sequence of events follows:
• Test processor sanity.
• Check ROM.
• Check NVRAM.
• Check RAM.
• Check DUART.
• Check Disk Sanity.
• Self-configuration (build the EDT).
• Run normal diagnostics on all equipped boards/cards listed in the EDT.
• Boot the UNIX operating system.
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