IBM 3274 51C Maintenance Information page 265

Write Data
)
+Inner Tracks
)
From
+Write Gate
)
Host
System
+Select
H~ad
1 )
+Erase Gate
)
+Switch
Filter
~
TPB06
TPC02
TPB04
TPB03
TPA06
TPD02
TPCTO
TPCTI
Figure F-18. 51TD Test Points
PTXCP
5 1
TPA10
1000
01
I
0 0
D
0
TI'B07
0 0
1
0
0 0
0 0
0
TPEOI
0 0
0
TPFOI
0 0 n
TPGOI
0 0
0
TpHOI
0
0 0
TPLD2
0 0
0 0 0
TPLDI
0
0
0
0
0
0
0 0
0 0
1/0 CP
0 0
0 0
0 0
18
B A
6
8)
1
1
00
o 01
SCI'
LEDCP
00 0
I
PTXCP - PTX Connector Pins
I/O CP - I/O Connector Pins
LEDCP - LED Connector Pins
SCP - Solenoid Connector Pins
- Head Connector Pins
Select
Logic
TPAOB
o
0
Tl'llOG 0 0
TPC030
TPU020
HCP
SMCP - Stepper Motor Connector Pins
Figure F-19. 51 TO Control Card
-5V de
o TPAOG
o
0 0
o 0 TI'COI
o TI'UOI
TPC03
Preamp
TPAMPI
@
Read/Write Head 0
Erase Head 0
Read/Write Head 1
Erase Head 1
o
lI'lllll
TI'A
TPll
TI'C
TpD
TH
TPE'
TpF
TpC;
TPH
IIIIU!!II&iCl
ill
8
D
Dill
Read
A
TPHOI
+File Data
DET
To
Host
System
Data Degate
TPGOI
+Write/Erase Enabled
o TPA05
o
o
0
o TpAOI
SMCP
G
0000 0
TPAMp2 0 o TPAMPI
D
o TpCTO
o TpeTl
14 HCp
0 0 0 0 0 0 0 0 0 0 0 0 0
Appendix F. IBM 51 TD Diskette Drive Maintenance P-21