Technical information

Chapter 1
Base System Description
This chapter describes the VAX 4000 Model 300 base system, including the
following:
• Power-on self-tests
• Digital Storage System Interconnect (DSSI) architecture
• Specifications for the KA670-AA/-BA CPU and MS670-BA memory
1.1 System Overview
All VAX 4000 Model 300 base system components are housed in a BA440
enclosure, which contains a 12-slot backplane.
Each base system contains the following:
• A KA670-AA/-BA (IAOOO-Al-B) central processing unit (CPU) module
• From one to four MS670-BA memory modules.
The base system modules are located in the following BA440 card slots:
• Any MS670-BA memory modules are installed in slots 1 through 4.
• The KA670 CPU module is installed in slot 5.
The base system operates from the KA670 CPU firmware and the controls
on the console modUle. The firmware is described in Section 1.2. Base
system operation also integrates Digital Storage System Interconnect
(DSSI) technology, which is discussed in Section 1.5.
Figure 1-1 is a block diagram of the VAX 4000 Model 300 system.
Base System Description 1-1