To start: portmir -t /dev/tty0 To stop: portmir -o ( on another session ) bootinfo -K reports whether the system is running a 32-bit or a 64-bit kernel - AIX4.3 has only a 32-bit kernel - AIX5.1 has both 32-bit and 64-bit kernels. Only one  can be active on a system [or within a LPAR] at a time. bootinfo -y reports whether the CPU is 32-bit or 64-bit. Command to tell if an executable is 32 or 64bit: dump -ov filename | grep bit COMPATIBILITY OPTIONS: Appl System User Kernel Mode Mode Hrdw Compatible ------ ------ ------ ----------- Option 1: 32-bit 32-bit 32-bit Note #6 Option 2: 32-bit 32-bit 64-bit Note #1 Note #6 Option 3: 32-bit 64-bit 32-bit Note #2 Note #6 Option 4: 32-bit 64-bit 64-bit Note #5 Note #6 Option 5: 64-bit 32-bit 32-bit Note #2 Option 6: 64-bit 32-bit 64-bit Note #1 Note #4 Option 7: 64-bit 64-bit 32-bit Note #2 Option 8: 64-bit 64-bit 64-bit Note #3 Note #4 Note #5 Note #6 Note 1: Requires AIX4.3 or later. Note 2: Invalid - not possible to run a 64-bit kernel on 32-bit hardware. Note 3: Requires AIX5.1 or later. Note 4: 64-bit user-space appls: bos.64bit fileset must be installed and activated using the command: "smit load64bit" AIX4.3 64-bit appls are not supported on AIX5.1. They must be recompiled. Note 5: The AIX5.1 32-bit kernel is default. The AIX5.1 64-bit kernel is optional. The AIX5.1 64-bit kernel is installed on 64-bit hrdw by default, but is inactive. The AIX5.1 64-bit kernel can be activated at install-time or later using the command: "smit load64bit" Use "bootinfo -K" to determine which kernel is running. Use "lslpp -h bos.mp64" to determine if the 64-bit kernel is installed. Note 6: AIX5.1 runs AIX4.3 32-bit user-mode appls without any changes.
oslevel reports version and release ( doesn't report Maintenance Level ) oslevel -r reports the AIX version, release ? service level. ( not working before AIX4.3.3 ML07 I think ) oslevel -rl 5100-04 reports what is missing to be at 5100 Maintenance level 04. Other ways: uname -vr ( works for all AIX versions ) ( revert the numbers ) 1 5 means 5.1