2-17
SIMATIC PC RI25/45, Technical Description
C79000-G7076-C808-01
X34
Function
Open
Types of 100, 120, 133, 233 MHz
Closed
Types of 150, 166, 200 MHz
Jumper X801 always open
S1 (4)
S1 (5)
S1 (6)
Function
on
x
x
VGA disabled
off
x
x
Onboard VGA (standard setting)
x
on
x
Clock ratio CPU BUS/-CORE 1/2 or 2/5
x
off
x
Clock ratio CPU BUS/-CORE 2/3 or 1/3
x
x
on
Clock ratio ISA/PCI 1/4
x
x
off
Clock ratio ISA/PCI 1/3
The effect of the switch setting S1 (5) depends on jumper X34.
S2 (5)
S2 (6)
Function
on
off
66MHz CPU bus clock (standard setting)
off
on
60MHz CPU bus clock
on
on
50MHz CPU bus clock
off
off
Reserved (test mode setting)
Jumper for
Setting the CPU
Type
S1 Display Type
and Bus Clock
S2 Hardware
Configuration
and CPU Clock
Motherboard