The polled I/O interfaces are only available under the following circumstances:
When you enter the OpenBoot PROM by using the L1+A keystroke sequence
When you boot the system with a standalone debugger such as kmdb(1)
When the system panics
The polled I/O interfaces only become available at a certain point in the boot process. Polled I/O requests issued from the OpenBoot PROM before the system is running are not rendered. Similarly, kmdb prompts issued before the console is configured are not rendered.
To test the polled I/O interfaces, enter the OpenBoot PROM by using the L1+A keystroke sequence. To validate that the polled I/O interfaces are being used, type the following command at the OpenBoot PROM ok prompt:
ok 1b emit ." [32m This is a test" 1b emit ." [m"
The polled I/O interfaces are working properly if the following statements are true:
The result of the above command is that the phrase This is a test is displayed in green.
The OpenBoot PROM continues to function correctly.
Scrolling performs as expected.
The cursor displays correctly.
The system can be reentered and continued repeatedly.