IBM System/360 2050 Maintenance Manual page 91

Processing unit
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Figure 79 represents the sense scheme for the
M9A, which is the only significant difference be-
tween the M9
and
M9A. Note that the following
cards are
~interchangeable.
Function
M9
M9A
Sense Amp
5804927
5808249
Final Amp
5804920
5808250
Strobe
5804910
5808254
Timing
5804815
5808253
The array part number is 2511311 for both the M9
and M9A.
Figure
80
shows waveforms for the M9A BSM.
The sync point is storage select A1H6G5 for all
waveforms.
LOCAL STORAGE (LS) SERVICE CHECKS
Local Storage Timings
Local storage timing information is in
AW
Volume
1, Page AAOOO.
Local storage zero time is defined as CPU 255
time.
LS Read Operation
The gate drivers and read drivers supply the current
to reset the core and induce an output on the sense
winding.
LS Write Operation
The gate drivers and write drivers select the word,
and the bit drivers supply the additional current
necessary to set the core. A bit driver must be on
for each position to be set.
LS Functional Packaging
Local storage drivers and sense amplifiers are
functionally packaged as follows:
1.
The eight gate drivers are packaged four per
card with one fuse per card.
2.
The eight read drivers are packaged four per
card.
3.
The eight write drivers are packaged four
per card.
90
(3/71)
Model 50 FEMM
Add Bit
i3
Add Bit 14
SA Gate
+Read
Set SA
Gote Latch
A
SA
Gate
Other {
Segs
Reset SA Gate Latch
Strobe B
Add Bit
14
Add Bit
13
Strobe B
Add Bit
14
Add Bit 13
Strobe A
Add Bit 14
Add Bit
f3
Strobe A
Add Bit 14
Add Bit 13
Strobe
1 Lower
2 Lower
3 Lower
4 Lower
5 Lower
6 Lower
1 Upper
2 Upper
3 Upper
4 Upper
5 Upper
6 Upper
Bits
0,
1;"2
3, 4, 5
6, 7, 8
9, 10, 11
12, 13,
14
15
16
17
18, 19, 20
21, 22, 23
24, 25, 26
27, 28, 29
30, 31, 32*
33,
34,
35*
Strobe 4
Upper
FIGURE 79. M9A STROBE AND SENSE CIRCUITS
Bits
St or
Out
Bus
32
=
p 0-7
33
=
p 8-15
34
=
p 16-23
35
=
p 24-31
4.
The 36 bit drivers are packaged four per
card with four fuses per card.
5. The 36 sense amplifiers are packaged four
per card.

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