IBM System/360 2050 User Manual

Local Storage Word Selection
Figure 81 shows how the local storage word is
selected from the six-bit address.
Gate Drivers
0
1 2 3
4 5 6
7
7
7 15 23 31 39
47
SS
63
6 6 14 22 30 38
46 S4 62
s
5 13
21 29 37 45 53
61
4 4 12 20 28 36
44 S2 60
R/W
Drivers
3
3
11
19 27
35 43 SI
59
2
2 10 18
26 34 42 so 58
I I
9 17 2S
33 41 49 S7
0
0
8
16
24 32
40 48
56
0
1
2
3
-----Sector -----
Sector
Word
(8) Gote (8) R/W
Driven Driven
FIGURE 81. LOCAL STORAGE ADDRESS BIT FUNCTIONS
LS Temperature Control Unit Check
Following is the procedure for calibrating the local
storage temperature control unit (TCU) using resis-
tor assembly P/N 461614 and a standard 6-pac card
extender P/N 452554. Proper use of this procedure
results in the correct TCU setting for controlling
the local storage array at a temperature of 1040F,
±lo. Resistor assembly P/N 461614 is a 1%, 8250-
ohm resistor with two SLT pluggable terminals.
Initial Setup
1. Turn off all power to the local storage unit
and TCU. The TCU is located in the power supply
section.
Caution
The TCU has a single phase, 60 cycle, 208-230
vac input on terminals Ll and L2.
2. Remove the cover from the TCU and insure
that the ac input power terminals Ll and L2 are
properly insulated or enclosed. Correct any safety
violation before continuing.
92 (3/71) Model SO FEMM
3. Connect the standard 6-pac extender jumpers
and resistor assembly P /N 461614. Refer to Figure
82 for card plugging.
4. Remove the dust protector around the array
board and unplug the SL T connector cable at the M2
location of the local storage array board.
5. Plug the SLT cable connector just removed
from the M2 into the SL T pin connectors on the 6-
pac extender (side opposite the jumper and resistor).
Make sure that the B and D sides of the cable con-
nector correspond to that of the 6-pac extender.
6. Plug the shroud end of the 6-pac extender
into the M2 position at the local storage array board.
7. Remove the two thermistor wires connected
to terminals Tl and T2, located adjacent to the in-
put power terminals of the TCU. Using an ohm-
meter calibrated against the 8250-ohm resistor,
measure the resistance between these two disc on -
nected thermistor wires. The meter should read
8250 ohms :1:1 %. If there is a higher resistance,
check for a bad crimp or broken wire and repair
before continuing.
8. Replace the two thermistor wires to TCU
terminals Tl and T2.
TCU Calibration Procedure
1. With an insulated screwdriver, turn the
potentiometer dial of the TCU to the extreme counter-
clockwise position.
2. Turn power on the local storage and the TCU.
3. With an oscilloscope, monitor the +30 volt
array heater voltage TCU return line located at
D4M2D07 on the local storage array board.
4. With an insulated screwdriver, turn the TCU
potentiometer dial clockwise until the heater just
barely turns on. The heater is on when the oscillo-
scope trace at D4M2D07 is at ground; the heater is
off when the oscilloscope trace is at +30 volts.
5. Turn power off. Remove the 6-pac extender
and replug the connector cable into the M2 position
at the array board.
6. Mark the position of the dial setting for
future reference. This setting should be at the 9 to
12 o'clock position. If not, the TCU may be defec-
tive. Recheck the procedure, especially step 7 in
the initial setup.
7. Correct operation is indicated by the heater
being turned on and off periodically.
Local Storage Waveforms
Typical waveforms for normal storage operation
are illustrated in Figures 83 through 87. These
waveforms are not to be used as specifications for
levels, rise times, fall times, or pulse widths, but
rather as general indications of the wave shapes to
be expected.

IBM System/360 2050 Specifications

General

Brand	IBM
Model	System/360 2050
Category	Computer Hardware
Language	English