Quoting Christian Limpach <chris@Pin.LU>:

> I'd give adding turbo support a try

I put code where my mouth is and here it is.  I just booted my coloUr turbo 
station multi-user with NetBSD and it's building the toolchain right now.
- only network, no SCSI (not tested, unlikely to work)
- only tested on coloUr turbo, don't have any other turbo machines
- only serial console, wsdisplay console doesn't work (display is messed up, 
at least on coloUr machines)
- bootloader and kernel will not work on non-turbo machines

Patches: (based on current as of 02-07-14)
- big-scsi[1] patch (also works on non-turbo)
ftp://lola.pin.lu/pub/NetBSD/arch/next68k/turbo/scsi-07-14-current-07-14.patch
- turbo support (apply after applying big-scsi patch)
ftp://lola.pin.lu/pub/NetBSD/arch/next68k/turbo/turbo-07-21-scsi-07-14.patch

boot loader:
ftp://lola.pin.lu/pub/NetBSD/arch/next68k/turbo/turbo-07-21/boot-turbo

kernel:
ftp://lola.pin.lu/pub/NetBSD/arch/next68k/turbo/turbo-07-21/netbsd-TURBO.gz

The kernel has serial console on port A.

[1] includes all the modifications I mentioned in:
http://mail-index.netbsd.org/port-next68k/2002/07/11/0009.html
-- 
Christian Limpach <chris@Pin.LU>