System ROM,
Continued
System ROM
Set Format
Table 2–5 shows the physical addresses in the system ROM. These
addresses are fixed.
Table 2–5 System ROM Physical Addresses
Physical Address
Name
Description
2004.0000
Processor restart
The hardware begins execution at this
address when:
Power is turned on.
Kernel mode halt instruction
executes.
A break signal is received from the
console device.
The HALT button is depressed.
The CPU detects a severe corruption
of its operating environment.
2004.0004 SYS_TYPE
System Type
register
The system type value longword is
0401.0001.
2004.0008
ROM Part data
These 24 bytes are reserved for
information contained in each ROM byte.
2004.0020
Interrupt vector
numbers
These eight longwords are not used by the
Model 90.
2004.0060
Console I/O
routines
There are eight I/O routines provided in
the system ROM. Entry points for these
routines are located at longword intervals
in the area.
2004.0080
Reserved
Reserved so all ROM set data that follows
it will be in the same relative position.
2004.0088
System console
firmware
revision number
This word contains the system console
firmware revision number.
Continued on next page
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