These files go at /sys/src/9/bitsy and are intended to let 9bitsy suspend/resume by pressing the on/off button. Beware that I've tested them only on a 32M bitsy. Beware also that you need a recent compaq bootldr installed. I have tested it only with Compaq OHH BootLoader, Rev 2-14-5 [BIG_KERNEL] [MONO] on a 206 MHZ ARM, ver 1/part b11/step 8 bitsy To get plan 9 booting with that bootldr, you have to apply the patch I sent days ago for the arm il.s. (bootldr seeks into the kernel memory to find some magic number and refuses to boot when there's no such number). This is what I have changed: power.c: the code for suspend/resume l.s: couple of aux routines clock.c, devµc.c, sa1100uart.c, fns.h, io.h, mem.h, screen.c, and trap.c: I added xxxpower() routines and sometimes I moved declarations of machine registers to io.h so power.c could access them. Another thing I have to say is that my arm assembler knowledge is pretty bad, in particular, l.s could shrink a lot by using movm instructions, whose a5 syntax is not yet clear for me. All the files changed are included in the attached .tar.gz file. enjoy.