IBM 2025 Maintenance Manual page 141

To Card
4649
C-B2U4
Twisted
Pair
{
U 4 Bl;ellow
U4
Dl2 Black
53
Twisted
Pair
Twisted
Pair
{
U
4
Yellow
D06
u
4
B08 Black
53
{
U
4
Yellow
G07
53
U4
o-------_.
G09 Black
{
U
4
Yellow
J06
53
Twisted
Pair
U4
o-------------_.
J09 Black
Y Read
53
53
Y Write
X Read
53
53
X Write
NOTE: All the black wires are grounded in card 4649,
pins Dl2, B08, G09, J09 being internally grounded.
Some machines have yellow wire grounded.
Figure 1-124.
x
ana Y source Resistors
L1
Ir'
Read Cal 1 ·(Sync)
~
o-
o.
0
.J
-
~
l
:.l
t._
'\
LL!i
I\
100 ns/Div.
2V/cm
Figure 1-125.
b
- Read Call (B2A3Dl 1)
- Start Write Cycle (BlC4JlO)
-r-
J
~
- Store Byte 0 (B 1A3B13)
v
- Read Echo (B 1D5D05)
storage Controls
0-
0-
Sense Bit 0 (Bl G2D09)
L..:::l::==:::±:i~l:::!..l~:t:=C==::l:=:;:t::::::jt:::::::t
-1 Changing to l
11
1
11
-Bit
100 ns/Div.
2V/cm
11
1
11
-Bit
Figure 1-126. Read Cycle Controls
Read Call
(Sync}
- Read Call (B2A3Dll)
0- t-....P-+-..+-+-b"""T'--t--1-""T"--I- Reset Byte 0 (B 103B 12}
0 -
l=::±=:±:::::l::::::t:::::'.'.:L.li:t::=:5;t::=::1==::t:=:1 -
Gate In Byte 0 (Bl D4D06)
(Equivalent to
100 ns/Div.
2V/cm
Equivalent
to Strobe
on Read
Strobe on READ)
(No Strobe on
Store Cycle}
Figure 1-127. Store Cycle controls
0-
- Read Call (B2A3Dl l)
[2V/cm]
1-----+-----t--T---tt-----i--;---,---r-~
-
X Current Read (B2U5B07}
Source [lOV/cm]
~t:tt~-f+i4""""'~~~~~~~:±;!;!*~-
Y Current Read (B2U4Bl2)
Source [IOV/cm]
IOO ns/Div.
Figure 1-128. X-Y Read current Source
Driver at the Resistor
2025 FEMM (7/69) 1-131