Using the GENERIC kernel from
<ftp://ftp.netbsd.org/pub/NetBSD/arch/sparc/snapshot/1.4.2/binary/kernel/netbsd-GENERIC.gz>
(downloaded today), I still get a crash when booting my SLC.  The 1.4
kernel that Steven Grunza built for me some time ago (with floppy support
and non-sun4c stuff excluded) works fine.  Here's what remained in my
message buffer after I rebooted: 

--------8<--------
): Sun 4/20
cpu0 at mainbus0: MB86900/1A or L64801 @ 20 MHz, WTL3170/2 FPU
cpu0: 64K byte write-through, 16 bytes/line, sw flush: cache enabled
memreg0 at mainbus0 ioaddr 0xf4000000
clock0 at mainbus0 ioaddr 0xf2000000: mk48t02 (eeprom)
timer0 at mainbus0 ioaddr 0xf3000000 ipl 10 delay constant 7
auxreg0 at mainbus0 ioaddr 0xf7400000
zs0 at mainbus0 ioaddr 0xf1000000 ipl 12 softpri 6
zstty0 at zs0 channel 0
zstty1 at zs0 channel 1
zs1 at mainbus0 ioaddr 0xf0000000 ipl 12 softpri 6
kbd0 at zs1 channel 0 (console)
ms0 at zs1 channel 1
fdc0 at mainbus0 ioaddr 0xf7200000 ipl 11 softpri 4: chip 82077
fdc0: no drives attached
audioamd0 at mainbus0 ioaddr 0xf7201000 ipl 13 softpri 4
audio0 at audioamd0: full duplex
sbus0 at mainbus0 ioaddr 0xf8000000: clock = 25 MHz
dma0 at sbus0 slot 0 offset 0x400000: rev 1
esp0 at sbus0 slot 0 offset 0x800000 level 3: ESP100, 25MHz, SCSI ID 7
scsibus0 at esp0: 8 targets, 8 luns per target
le0 at sbus0 slot 0 offset 0xc00000 level 5: address 08:00:20:00:ee:00
le0: 8 receive buffers, 2 transmit buffers
bwtwo0 at sbus0 slot 3 offset 0x0 level 7: SUNW,501-1455, 1152 x 900 (console)
bwtwo0: attached to /dev/fb
data fault: pc=0xf007a374 addr=0x70 ser=80<INVAL>
panic: kernel fault
syncing disks... done
Frame pointer is at 0xf01dbab8
Call traceback:
  pc = 0xf01a539c  args = (0x4010e6, 0x401fe6, 0x0, 0x0, 0xf01dbbd0, 0x9010e6, 0xf01dbb20) fp = 0xf01dbb20
  pc = 0xf005ae10  args = (0x100, 0x0, 0x0, 0x0, 0xf01dbc44, 0x9010e0, 0xf01dbb88) fp = 0xf01dbb88
  pc = 0xf01b543c  args = (0xf01b50e8, 0x100, 0x70, 0xf01dbc50, 0x37, 0x1, 0xf01dbbf0) fp = 0xf01dbbf0
  pc = 0xf000857c  args = (0xf020eac8, 0x80, 0x70, 0xf007a374, 0x40, 0xf01dbcf8, 0xf01dbc98) fp = 0xf01dbc98
  pc = 0xf013b194  args = (0x0, 0xc, 0x4e, 0x0, 0x0, 0xf02dfce6, 0xf01dbd48) fp = 0xf01dbd48
  pc = 0xf013ad64  args = (0x0, 0xf02dfc00, 0xf0212550, 0x3, 0xf0caa060, 0xf020d000, 0xf01dbe00) fp = 0xf01dbe00
  pc = 0xf007b174  args = (0x0, 0xf02a8a00, 0xf01dd74c, 0xf020ec00, 0x0, 0x800, 0xf01dbe70) fp = 0xf01dbe70
  pc = 0xf0044d38  args = (0xf01e4490, 0xf002d078, 0xf020d81c, 0xf020d824, 0xf020d818, 0xf020d820, 0xf01dbed8) fp = 0xf01dbed8
  pc = 0xf000987c  args = (0x0, 0xf0212550, 0xf00021b8, 0xf01dc06b, 0xffffffff, 0x10, 0xf01dbf50) fp = 0xf01dbf50
  pc = 0x300524  args = (0xffffffff, 0x30c400, 0xffe9501c, 0x306ac8, 0x1f6, 0x22663c, 0xefffffa0) fp = 0xefffffa0
rebooting
-------->8--------

If there's anything else you need to know, please ask.  I'd really like
this machine to be able to use GENERIC kernels.

-- 
Ben Harris
Unix Support, University of Cambridge Computing Service.