Other Circuits; Speaker; Ram Jumpers - IBM AT 5170 Technical Reference

adapter. If the parity check was from that adapter, -I/O CH CK
will be reset to inactive.
Other Circuits
Speaker
The system unit has a 2-1/4 inch permanent-magnet speaker,
which can be driven from:
• The I/O-port output bit
• The timer/counter's CLK OUT 2
• Both of the above
RAM Jumpers
The system board has a 3-pin, Berg-strip connector
(JI8).
Starting at the front of the system, the pins are numbered 1
through 3. Jumper placement across these pins determines how
much system board RAM is enabled. Pin assignments follow.
Pin Assignments
1
No Connection
2
- RAM SEL
3
Ground
RAM Jumper Connector (J18)
1-40 System Board