IBM 3274 51C Maintenance Information page 203

ReadlWrite Head
Center Tap ReadlWrite Head
ReadlWrite Head
White
Green
Black
HeadO
ReadlWrite
Erase flead Red
.=:;..:.;...:..:..:..::..::..... _ _ _ _ _ _ _
~""__+..rtCT'__.
flead 0
Head Connector (HCPI
Dill
Write Data B 17
-5 Vdc
+Inner Tracks BOB
Select
I--+W:..:..r:..:..it:..:..e.:::.G:..:..at.:::.e _ _ _
--=B;.;I...;.4~>....;;...c:....:c..;..;.._t_-+--_;
Logic
+Erase Gate B09
+Write/Erase Enabled B06 I/O BOO
+File Data B07 I/G B07
I/O A02· TPC04
~G~r.:::.o:..:..un;.;d~--~A~0.:::.2...;..A~I.:::.8~)--A~18~+_----~-oTPFOI
01 LED Voltage
-5Vdc AOI I/OAOI
+5 Vdc
BOI
I/O BOI
B04 I/O B04
Using
~+:...:.I:.:.:nd::.::e::..x----_----..::.:.....=..(~:=..::.::..~+----------
.... -_<
System
Adapter
+Oiskette Sense
B05
I/O B05
-Disable
Stepper
Motor
+Access 0 Bl0 I/O BIO
TPCOI
+Access I B13 I/O B13
+24 Vdc
B03 I/O B03
TPAOI
+5V
MC.O
=
Ground
TPH04
Erase
LED BOI
PTX AOI
PTX A03
LEO AOI
SM A06
SMA05
SM A04
SM A03
SMAOI
SOL A03
BOI 01 LEAD Voltage Black
31SD
AOI 01 PTX Black
PTX
A03 01 PTX Return
AOI 01 LEO Ground Red
A06 Stepper Motor MC·O Yellow
A05 Stepper Motor MC·I Red
A04 Stepper Motor MC·2 Orange
A03 Stepper Motor MC·3 Blue
AOI Stepper Motor Common Black
A03 Head Load Solenoid
31S0
Stepper
o
Motor
3
White Head Load
+Head Engage BI5 I/O 815
f"
L
Card Position
~connector
Position
~-
......
----=----------------~~S:::0:.:L:...:.A..:;04~f_:..;A.::.04.:.._--:..;H;.:ea:.:d.:::.L:.:o.:;ad~-
_ _
--=:8:.::la~ck;....r
Solenoid
Card Position
J"
l
Notes:
1. A jumper from ground to disable stepper motor over-
rides any input access lines. This is used in making
head/stepper motor adjustments.
2. The variable frequency oscillator is packaged in the using
system logic. The function of the variable frequency
oscillator is to separate and clock pulses.
Figure .E-11. Control Lines at Connector A 1
E-14
Connector Position
~
.---