AT&T 3B2/300 Technical Reference Manual page 146

EQUIPMENT D E S C R I P T I O N - - - - - - - - - - - - - - - - - - - - - - - - - -
CM191B 1-Megabyte RAM Card
The CM191B 1-Megabyte RAM Card is a multilayer board containing eight 256K by 4-bit DRAM
SIPs (for data), four 256K by 1-bit DRAM chips (for byte parity), and two driver chips. Thirteen bypass
capacitors and one resistor network are also on the board. All components are mounted on the front
side of the board. Connection to the system board is via a 72-pin edge connector. Card pinout
information is provided in Appendix B. The card is 1.6 inches high by 7.9 inches wide. Figure 2-29
shows the component layout of the CMl 918 Card.
lr
1.6"
y
r···································
7.9.. • ••••••.•••••••••••••••••••••••••• ,
Cl C l . . . - - - - - - - - - ,
c:::J ,-------,
Cl
Cl
c:::J .-------,
01
c::========:::::J
Cl Cl
,--------, c:::J c:::J
_ _ _ _ _ _ ...., Cl Cl
-------, c:::J c:::J
71
A. Front View
1918
172
B. Rear View
Figure 2-29: CM191B 1-Megabyte RAM Card Layout
2-122 TECHNICAL REFERENCE MANUAL