Service manual

The console and diagnostics sections include:
• A console read-only memory (ROM). This ROM contains code to
initialize and boot the system and execute console commands. The last
line of the self-test display shows the ROM version. In this example,
the callout
1
indicates that the console ROM is version 6.0.
• A diagnostic ROM, which contains the power-up self-test and extended
diagnostics. The diagnostic ROM has the same version number as the
console ROM
1
.
• An electrically-erasable, programmable ROM (EEPROM), which
contains system parameters and boot code. You can modify the
parameters with the console SET commands. Patches read into a
special area of the EEPROM patch the console and diagnostic code in
ROM. A program run under the VAX Diagnostic Supervisor is used
to patch the EEPROM. See Section 3.15, Patching the EEPROM with
EVUCA.
The last line of the self-test display shows two EEPROM version
numbers. The first number
2
indicates the format version of the
EEPROM. This version is changed only when the internal structure
of the EEPROM is modified.
The second number
3
is the revision of ROM patches that have been
applied to the EEPROM. The major number in this revision (before the
decimal point) corresponds to the major number of the ROM revision
1
.
The minor number indicates the actual patch revision. In this example,
the EEPROM has been patched once for console ROM 6 and the patch
revision is .1 .
The location of the two ROMs and the EEPROM can be seen in
Figure 3–1, Section 3.1.
• A system support chip (SSC) contains circuits for writing the EEPROM,
controlling the console, and timer support. On the module, the red LED
next to the yellow LED is controlled by the SSC. When the power-up
tests have completed successfully, the SSC on the boot processor turns
off this LED.
<REFERENCE>(xyp) Scalar Processor 3–9