Hardware Components Of The 3708; 3708 Base - IBM 3708 Description

Hardware Components of the 3708
3708 Base
The 3708 hardware consists of a base and cartridge. This section describes each of
these parts.
The base contains the circuitry to operate the 3708. This includes:
• A Motorola MC68000 Microprocessor®
• EIA 232C Interface Drivers and Receivers
• EIA 422A Interface Drivers and Receivers
• A System Control Logic Module
• A red light emitting diode (LED), described in Chapter 2
• A green LED
• A power switch
• A test/normal switch
• 128K bytes of random access memory (RAM)
The 128K of RAM is used for control blocks, buffers, and storing operational
copies of the following:
Configuration
Error log
Alert log
User-defined translate table
User-defined terminal tables
Patch data.
• 8K bytes of electrically erasable programmable read only memory (EEPROM).
The 8K of EEPROM is used to store the following:
Vital product data
Extended Error Information Field (EEIF)
Error log
Alert log
Patch data (microcode temporary fixes)
User-defined translate table
Six user-defined terminal tables
Customer configuration.
The base has ten ports for connecting EIA 232C or EIA 422A cables. Refer to IBM
3708 Network Conversion Unit Planning and Installation for a description of the 3708
EIA 232C and EIA 422A interfaces and cables. The base (as shown in Figure 1-1
on page 1-2) has two switches: a power switch and a test/normal switch. The
test/normal switch is used for the following procedures:
• Initiate the 3708 extended diagnostic test
• Temporarily reinstate the IBM-supplied configuration
• Exit a port testing mode
• Exit a restart loop condition.
These procedures are described in IBM 3708 Network Conversion Unit Problem
Determination.
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IBM 3708 Description