Technical data

Central Processor Unit, Continued
System
Support
Subsystem
The system support subsystem handles the basic functions
required to support the console in a system environment. This
subsystem contains the firmware ROMs, the firmware ROM
controller, the configuration register, and the station address
ROM.
Resident firmware ROM is located on four chips, each 128 KB by
8 bits of programmable FLASH EPROM
1
, for a total of 512 KB of
ROM. The firmware gains control when the CPU halts.
ROM Firmware
ROM firmware provides the following services:
Board initialization
Power-up self-testing of the KA49 module
Emulation of a subset of the VAX standard console (auto
or manual bootstrap, auto or manual restart, and a simple
command language for examining or altering the state of the
processor)
Booting from supported Ethernet or SCSI devices
Multilingual translation of key system messages
Configuration
Register
The configuration register allows the firmware and the operating
system to read KA49 configuration bits. These bits indicate which
options are present and the size of the physical memory.
I/O Subsystem
The I/O subsystem contains the following:
CP-Bus adapter
SCSI mass storage interface
Ethernet interface
Optional bus adapter interface
Optional synchronous communication interface
1
A FLASH EPROM is a programmable read-only memory that uses electrical (bulk)
erasure rather than ultraviolet erasure.
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