IBM System/360 2050 Maintenance Manual page 193

Main Storage (cont)
preventive maintenance schedule 79
ripple teat procedure 56
scan for bad parity (program) 82
service checlal 80
strobe checking 82
teat points 80
temperature and humidity 81
waveforms 88
Main store mode 20
data paths 20
entries/objectives/controls 20
FLT 1
s
45
instructions, FLT op reg 22
logout, portion of 24
operations 18
ripple (teat patterm) 20
ripple (teat procedure) 56
timing 20
trigger and request logic 37
Maintenance operations 18
Maintenance philosophy 11
Marginal checking 75
Meter, voltage 140
Metering 154
Mover latch pulse, block 64
One-cycle teats -- see fault locating tests
Operating instructiom 155
Operator control section 154
Optional feature version codes 13
Overcurrent -- see power system
Overvoltage -- see power system
Parity
bit propagation/generation 23
checking, channels 77
checking, CPU 76
checking,
1/0
erron 73
checking, main storage 73
generator 28
Pass trigger 33
Physical data 138
Power
and cooling failure detection 76
display section 140
distribution frames 127
faults 12
off 157
OD
154, 157
requirements 139
Power system
AC supplies 125
converter-inverter troubleshoot:iDg 120
failure detection, power/cooling 76
marginal checking 75
overcurrent problems 125
overvoltage unit adjustment 125
+1S vdc sequence
down
124
prevent! ve maintenance schedule 79
SCR gate signals 121
sequence problems 123
sequencing relays 123
voltage regulator problems 125
voltage regulator teat points 123
192 Model 50 FEMM (3/71)
voltage regulaton, changing 123
waveforms (SCR gate signals) 121
Preventive maintenance
79
Programming faults 12
Progressive scan 63
documentation, multiplexor channel 74
documentation, selector channel 72
interface register 64
monitor, selector scan 74
operating procedure, multiplexor channel 74
operating procedure, selector channel 72
selector channel clock control
71
selector scan monitor 74
tape/disk, multiplexor channel 74
tape/disk, selector channel 71
teat descriptions 63
teat patterm 71
Progreaive scan stat 33
Protect key, display and store 160
PSW, display and store 156
Read-only storage (ROS)
bit plane adjustments 100
bit plane cleaning 100
bit plane connectors 102
bit plane installation 101
bit plane removal 100
bits, missing or extra 97
clock atop trigger 38
drive line teats 98
function check 156
preventive maintenance schedule 79
retry timing 95
ripple teat 98
waveforms 96
Regiaten -- see functional units
Relays/contacton 127
Repeat instruction (IAR) 152
Reset, system 151
Ring counter -- see sequence counter 22
ROS -- see read-only storage
ROS kemels 22
ROS mode 18
entries/objectives/controls 19
Fl.T's 48
instructions, FLT op reg 23
logout, portion of 24
operations 19
triggen and request logic 37
ROS retry timing 9S
ROS testing 97
ROS 201 -- cycle one section of local storage 95
Safety procedures 5
Scan bus, inputs to 28
Scan control triggen -- see FLT op reg 22
Scan counter -- see sequence counter 22
Scan fail stat -- see fall trigger 33
Scan groups 28
Scan-in, FLT -- see fault locating tests
Scan-in (ROS kemel) 22
Scan/log decoder 22
Scan op reg -- see Fl. T op reg 22
Scan-out, FLT -- see fault locating tests
Scan-out (ROS kernel) 23