Turbo Switch Connector
The Turbo switch (TURBO) is a 2-pin BERG strip. It is used to connect
the front panel 2-position push switch to the system board speed
switching circuitry. In Turbo speed, the cache memory is enabled and full
speed of 32-bit memory transfer is utilized. In non-turbo speed, the
cache memory is disabled. In both speeds, the ISA expansion bus timing
compatibility is still preserved.
Pin
Description
1
Turbo Speed
2
Ground
Notes:
-
System runs at Turbo speed when pins 1 and 2 are shorted.
-
System runs at Slow speed when pins 1 and 2 are open.
Turbo LED Connector
The Turbo LED connector, marked as 'TB/LED', is a 2-pin BERG strip. It
is used to connect a CPU operating frequency indicator LED from the
front panel to the system board. The pin assignments are indicated
below:
Pin
Description
1
LED Cathode
2
LED Anode
Page 16 486MIS System Board User's Manual
