What am I doing wrong?

hi,

I'm sure I must be overlooking something really simple and obvious, or just 
doing something stoopid :o) Having not managed to get a kernel to boot 
successfully on an NC (see my previous message, "Bootloader problems on an 
NC" - I've now tried several NCs to rule out faulty hardware) I decided to 
try installing NetBSD on my RiscPC 600, partly to simply get myself a NetBSD 
system to play with and partly so that I could try compiling a new kernel for 
the NC from the latest source.

Using BtNetBSD 0.99a, set up according to the docs, together with the 
installation kernel, I tried to boot into NetBSD to begin installation. The 
loader found the memory OK (16M+16M+2M), did the various memory-mapping and 
relocation stages then did the 5-second countdown. Then the system locked 
solid when the loader said "start!"

I've also tried various other kernels for the RiscPC, and a generic one, with 
exactly the same result. The same thing happens if I boot to the supervisor 
prompt then run "!BtNetBSD.BtNetBSD $.netbsd" directly. (As an experiment, 
I've tried one of the RiscPC kernels on an NC just to see what happened; 
exactly the same result. I don't know whether one would expect to get any 
further than this, though.)

What have I missed?

Stephen