1 Hardware Overview
1.2 System Unit Block Diagram
Libretto 50CT/70CT Maintenance Manual
1-5
The system unit is composed of the following major components:
q
Microprocessor
Libretto 50CT: Intel 75 MHz Pentium processor operates at 2.9/3.3 volts and
incorporates the math co-processor and 16 KB cache memory.
∗
Libretto 70CT: Intel 120 MHz Pentium processor with MMX technology operates
at 2.9/3.3 volts and incorporates the math co-processor and 16 KB cache memory.
q
Standard RAM
•
16 MB, eight 1M x 16-bit EDO DRAM chips
•
3.3 volt operation
•
No parity bit
•
Access time 70 ns
•
Data transfer is 64-bit width
q
BIOS ROM (Flash EEPROM)
•
256 KB, one 256K x 8-bit chip
−
64 KB are used for system BIOS
−
40 KB are used for VGA BIOS
−
152 KB are reserved
•
Access time 120 ns
•
Data transfer is 8-bit width
q
Expansion memory
One expansion memory slot is available for 8 and 16 MB memory kits, which consist
of 1M x 16-bit EDO DRAM chips.
•
3.3 volt operation
•
No parity bit
•
Access time 70 ns
•
Data transfer is 64-bit width
q
Video Controller
Chips & Technologies F65550 is used. The video controller integrates an LCD/CRT
graphics controller, RAMDAC, and clock synthesizers.
q
Video RAM
•
1 MB, two 256K x 16-bit DRAM chips
•
3.3 volt operation
•
Access time 50 ns
Содержание Libretto 50CT
Страница 8: ...viii Libretto 50CT 70CT Maintenance Manual ...
Страница 10: ...Chapter 1 Hardware Overview ...
Страница 11: ...1 ii Libretto 50CT 70CT Maintenance Manual ...
Страница 30: ...Chapter 2 Troubleshooting Procedures ...
Страница 31: ...2 ii Libretto 50CT 70CT Maintenance Manual ...
Страница 61: ...Chapter 3 Tests and Diagnostics ...
Страница 62: ...3 ii Libretto 50CT 70CT Maintenance Manual ...
Страница 64: ...3 iv Libretto 50CT 70CT Maintenance Manual 3 22 2 Operations 3 45 ...
Страница 128: ...Chapter 4 Replacement Procedures ...
Страница 129: ...4 ii Libretto 50CT 70CT Maintenance Manual ...
Страница 167: ...Appendices ...
Страница 168: ...App ii Libretto 50CT 70CT Maintenance Manual ...
Страница 178: ...Appendix B Board Layout B 4 Libretto 50CT 70CT Maintenance Manual ...
Страница 183: ...Appendix C Pin Assignments Libretto 50CT 70CT Maintenance Manual C 5 ...
Страница 186: ...Appendix Appendix C Pin Assignments C 8 Libretto 50CT 70CT Maintenance Manual 43 GND 44 NC ...
Страница 194: ...Appendix F BIOS Rewrite Procedures F 2 Libretto 50CT 70CT Maintenance Manual ...
Страница 196: ...Appendix G Reliability G 2 Libretto 50CT 70CT Maintenance Manual ...