2Lars: Where to get??? On Hobbes. If the kernel is not properly work on your system, you should report that to the developers, so that they will fix it. But you don't want. So, who is guilty?
All available stuff is either on Hobbes, or at official webpage, http://gus.biysk.ru/os4/. All, who needs it, knows about it. os4apic.psd is documented in kernel readme's. At least, available command line switches. What else is needed? It is not ACPI implementation, because ACPI is separate from PSD. ACPI is available for interested testers (including me). It is a special kind of driver (a PDD, but it is loaded before PSD, and it communicates to PSD, so that PSD gets ACPI tables info from it. Alternatively, IRQ routing info can be get from MPTable). Drivers like CLOCK03c.SYS are mandatory, but they are loaded by kernel without the need to be written into CONFIG.SYS (the same way as CLOCK01.SYS. CLOCK03c.SYS is loaded instead of CLOCK01.SYS, and contains both CLOCK and TIMER drivers. Plus, it contains support for hi-res timer, based on HPET). The same for SCREEN03.SYS. There are also OEMHLP.BPD and ACPI4.BPD, which contain OEMHLP$ and ACPICA$ implementations. All these should be not written into CONFIG.SYS. Everything should be described in readme's, otherwise you can ask developers. They are responsive.
How do you know that I don't want ? In fact, I did install the OS4 kernel and along with it the OS4APIC.PSD.
The problem is that the OS4 components are spread across different places (there is no common zip, left alone an installation package). And it's unclear when and if you need ACPI4.BPD and OEMHLP.BPD.
Just to let you know: I have a 40-hour job and it has nothing to do with PC SW development. I don't have all day to find out how things work or where to find them. Then I have some own OS/2 related SW development going on. And then I have to maintain my existing OS/2 main installation and device driver development installation to ensure it is operational. Plus I have a couple of additional hobbies ...