Specifications

17 January 1997 – Subject to Change
System Configuration and Connectors 2–5
AlphaPC 164 Jumper Configurations
Figure 2–2 AlphaPC 164 Configuration Jumpers
2.1.1 Memory Bus Width Jumper (J1)
The memory bus width can be either 128-bits (J5 through J8 populated with SIMMs
and J9 through J12 empty) or 256-bits (J5 through J12 populated with SIMMs).
When using a memory bus width of 128-bits, jumper J1 must be in. When using a
memory bus width of 256-bits, jumper J1 must be out.
J30 System Configuration Jumpers
IRQ3
1
3
5
7
9
11
13
15
17
19
21
23
25
CF0
CF4
CF5
CF6
CF7
CF1
CF2
CF3
Mini-Debugger (Default Out)
Boot_Option (Default Out)
Reserved (Default Out)
IRQ0
IRQ1
IRQ2
Reserved (Default Out)
Not Used
Frequency Ratio IRQ3 IRQ2 IRQ1 IRQ0 Comments
All other combinations
In Out Out
Out In In
Out In Out
366 MHz
400 MHz
433 MHz
11
12
13
Out
Out
Out
Reserved
Bcache Size
Out
Out
All other combinations
CF1 CF2 Comments
1MB Out
In2MB
Reserved
Default
Bcache Speed
Out
All other combinations
CF4 CF5 Comments
9 ns Out
Reserved
Default
MK-2306-36A
1
2
3
2 to 3 In = Enable (Default)
1 to 2 In = Disable
1
2
In = 128-Bit Bus
Out = 256-Bit Bus
Note: Jumper must be out when all
eight DRAM SIMM sockets are populated.
J31 Flash ROM Update Jumper
J1 Memory Bus Width Jumper
Out In
Out
466 MHz 14 Out
Out Out500 MHz 15 Out Out