Service manual

System Overview 1-87
The standard I/O module provides basic I/O device interfaces to allow the
system to be tested, configured, and booted. These devices include:
• Keyboard and mouse support
• Asynchronous communication ports (local terminal port, COM1 (internal to the
module), COM2, modem port, USB ports)
• A multimode parallel port
• An internal SCSI UltraWide controller with an UltraWide disk and optional fast-
narrow CD-ROM/DVD
• An IDE controller for connection to CD-ROM or other ATAPI/IDE devices
In addition, the system control manager (SCM) microprocessor is located on the
standard I/O module. There are two interfaces to the SCM: the operator control
panel (OCP) interface and the console serial bus (CSB) interface.
Jumpers
J12 When installed, forces the SRM console defaults.
J13 When installed, forces COM1 bypass.
J18 When installed, forces the SCM defaults.
J17
When installed, forces the SCM to remain in fail-safe loader mode upon
reset.
The jumper station is three pronged and the installed position is indicated by a
silkscreen connection.
Functions of the SCM are described in Section 1.8.
The SRM console code also resides on the standard I/O module. After power-up
is complete and the SRM console code is running, the standard I/O module
becomes the local console port if so configured.
In partitioned systems, each partition requires, among other things, a standard
I/O module so that each partition has a console. See Section 1.9 for information
on partitioning.