I simply installed the standard OS/2 Advanced Power Management drivers from Selective Install. Note that these drivers make the operating system aware that the system is power-managed. This allows the operating system to communicate with the APM BIOS, and affects how devices are treated after a resume. It does not provide niceties like a hard disk spin-down.
Effectively then, these drivers allow you to use the standard BIOS power management functions. That means you still get all the PS2-controlled power management features.
Unfortunately, neither PS2 nor HSLEEP work under OS/2; PS2 exits with a polite message, but HSLEEP simply causes a TRAP.
To use PS2, you must shut down and reboot off a DOS disk (I use the 4MB Flash drive), run PS2 to configure to the desired settings, then reboot to OS/2. This is painful, so get your settings right first time!
I have not yet found a tools to spin-down the hard drive, but I haven't looked at the old PS/2 portable support diskettes - you could do some great things on the L40sx and the like under OS/2, like monitor the internal temperature of the machine, so I'd hope that one of these machines had some other software goodies that would work on the PC110. Wishful thinking...?
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