Specifically, PCR is controlled by a rotary dip switch on the P-7K9P C7 card. This rotary dip switch has 16 settings. A description exists in the circuit description document (OS-502160-005.
0 Basic 64kbit
1 Basic 56kbit
2 Basic 48kbit
3 Basic 40kbit
4 Basic 32kbit
5 Basic 24kbit
6 Unused
7 Unused
8 PCR 64kbit
9 PCR 56kbit
A PCR 48kbit
B PCR 40kbit
C PCR 32kbit
D PCR 24kbit
E Unused
F Unused