Chapter 2 Theory Of Operation - Sharp PC-7200 Service Manual

PREFACE
SCOPE
This manual contains the theory of operation for the PC-7200
microcomputer system, and is primarily intended for service
technicians working in the field or in repair centers. In addition, the
manual can also be used as a reference document for technical
____ personnel __ requirjng-__
knowledge-~of-this- -cdmpliteCTfis
co-il-f8i1fs-of
this manual are as simple and clear as possible, however, users of
this manual shOUld be 899uainted with computer hardware.
About The Manual
This manual is divided into seven chapters:
CHAPTER 1 PRODUCT DESCRIPTION
Provides general information on the computer such
as specifications and external and internal configura-
" tions.
CHAPTER 2 THEORY OF OPERATION
Describes the logical and electrical functions of each
cirCuit block.
CHAPTER 3 FLOPPY DISK DRIVE
CHAPTER 4 HARD DISK INTERFACE
CHAPTER 5 HARD DISK DRIVE
CHAPTER 6 ADJUSTMENT
CHAPTER 7 APPENDIX
NOTES: The 7200 Manual is generally concerned with the
PC-7221
product configuration which includes the high density
(2HD) floppy disk drive and 20MB hard disks drive.
PC-7201/720217221 are common except the difference
showed by the next list.
The difference from PC-7201, PC-7202 and PC-7221
PC
7201
PC
7202
PC
7221
FDD 1 x FDD(2HD) 2xFDD(2HD) 1 xFDD
HDD none none 1 xHDD
FDD,HDD FDD FDD FDD
Indicator FDD/HDD FDD HDD
SPECIAL SERVICE TOOLS
PARTS CODE
PRICE
TOOL NAME
BANK
1
UKOGM2018CSZZ _.3~ ...51
(CPU.B0286)·extrac1ionlool
2 DFLP-10B3ACZZ BF
Diagnostic media
3
DFLp·1084ACZZ
BF
Aging test media
1. UKDGM2D18CSZZ
o
o
2. DFLP-1 D83ACZZ
3. DFLP-1 D84ACZZ