Started from ver 4032 OS/4 kernel will load clock03b.sys instead of clock01.sys.
Clock03b uses Extended KEE, which includes KernSetIRQ and KernEOI (
http://ru2.halfos.ru/core/docs/keeOS4.html)
Clock03b contains two drivers CLOCK$ and TIMER0$ so timer0.sys no more needed, it will not be loaded any way even if it will not be removed from config.sys
As you may guess Clock03b has two _32_ bit only interrupt service routines (for IRQ0 and IRQ8).
Clock03b has many advantages comparative to pair clock01 + timer0 - it is based on source code from clock01 by Tsurgaev A.V. (Цургаев А.В.)
For those who is brave enough here is a link to download and test it.
http://ru2.halfos.ru/core/downloads/kernel/os4/os2krnlSVN4032_unoff.zip