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SERVICE CHECKS. ADJUSTMENT AND REMOVAL PROCEDURES
CPU AND CHANNEL SERVICE CHECKS
Waveform Measurements
All waveform measurements for the 2050 Process-
ing Unit are made to the following specifications
(Figure 52):
1. The rise time of a pulse is the time required
for the transition from O. 3 volts to
1.
8 volts as the
pulse is gbing in a positive direction.
2. The fall time of a pulse is the time required
for the transition from
1.
8 volts to O. 3 volts as the
pulse is going in a negative direction.
3. The width of a pulse is measured from the
1.
O volt point at the beginning of the transition on
the leading edge to the
1.
O volt point at the begin-
ning of the transition of the trailing edge.
4. The delay between pulses is measured from
the 1. 0 volt point at the beginning of the transition
of the leading edge of the first pulse to the same
point on the next pulse.
2050 Clock
The 2050 clock consists of a 4-megacycle oscillator,
which is frequency divided to 2 megacycles, and a
number of circuit delays which can be adjusted.
Oscillator pulses are shaped, delayed, and powered
to meet all system requirements.
I
All 2050 clock timings are on ALD AAOOO in
Volume 1 of the ALD's.
----Td_-f-.J ----- ,.1.0v
FIGURE 52. WAVEFORM MEASUREMENTS
80
(3/71)
Model SO FEMM
MAIN STORAGE (MS) SERVICE CHECKS
Storage Test
A rotary switch on the panel selects one of four test
patterns to be applied to main storage. When the
rotary switch is in the fifth position (process), the
test light is off (in the operator control section). The
four test positions are:
1. All ones
2. All zeros
3. Worst pattern
4. Reverse worst pattern
To operate the storage test:
1. Set the rotary switch to one of the four de-
sired positions.
2. Press the start pushbutton.
3. Set the write lever switch down to write the
desired pattern into storage. When the write lever
is down, SDR contains all ones regardless of the
position of the rotary switch.
4. Return the write lever switch to its normal
position to read/regen storage.
5. With the stop on check lever down, IAR con-
tains the address of the error word. Each depres-
sion of the start pushbutton resumes storage scan-
1
ning until the next error word is detected
Main Storage Test Points
Figure 53 shows important test points for the main
storage unit.
T =Rise Ti me
Tr=
Fall Time
Tw
=Pulse Width
Td =Delay
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