Axel, I tested the revisions you wanted me to test on my Via C3 machine - here is what I found: r15559 - boots through kernel, seg fault in app_server I believe (not sure what caused this - I had the same problem on my PIII machine also I think) r15560 - KDL on the Via machine - didn't get a chance to try this on the PIII though - I did see the debug output that refers to the MTRR - will include below r15863 - (figured I'd grab a newer rev) boots through kernel on Via, loads app_server, loads terminal, runs for a bit, did not see the same debug output as 15560 though The relevant debug output from the r15560 attempt was this: ...<snip> MTRR enabled 0: 0x0, 0xffff001, 6 1: 0x10000000, 0x7fff001, 6 2: 0x18000000, 0x3fff001, 6 3: 0x1c000000, 0x1fff001, 6 4: 0x1e000000, 0xfff001, 6 5: empty 6: empty 7: 0xf4000000, 0x3fff001, 1 MTRR 0: new mask fe0000000) mask test base: 0) mask test middle: 0) mask test end: 20000000) con_init: trying module console/frame_buffer/v1 loaded driver /boot/beos/system/add-ons/kernel/drivers/dev/console loaded driver /boot/beos/system/add-ons/kernel/drivers/dev/dprintf loaded driver /boot/beos/system/add-ons/kernel/drivers/dev/keyboard loaded driver /boot/beos/system/add-ons/kernel/drivers/dev/null loaded driver /boot/beos/system/add-ons/kernel/drivers/dev/random loaded driver /boot/beos/system/add-ons/kernel/drivers/dev/tty loaded driver /boot/beos/system/add-ons/kernel/drivers/dev/zero vm_soft_fault: va 0xdeae02ef not covered by area in address space vm_page_fault: vm_soft_fault returned error -2147478783 on fault at 0xdeae02ef, ip 0x800823b2, write 1, user 0, thread 0x24 PANIC: vm_page_fault: unhandled page fault in kernel space at 0xdeae02ef, ip 0x800823b2 Welcome to Kernel Debugging Land... Running on CPU 0 kdebug> <snip> If you need/want the entire text captures from the debug output, let me know here: umccullough <at> NOSPAMgmail <dot> NOSPAMcom I hope I built everything properly - there were only a few files different when I updated to r15560, which appeared to be processor-specific kernel files. I don't understand why the latest revision didn't include the MTRR debug output, unless you removed it or I need to enable something? If there's anything else you think I should test, or believe I did anything wrong, please let me know. Thanks for your efforts BTW :) - Urias