more progress in the 4.3tahoe on 4000/600 to report: i actually got it
booted! its not perfect yet, but the system does seem to be running
more or less ok. i compiled and ran the dhrystone benchmark, it got
a respectable 39787.. :) 
i went to try to compile a GENERIC just to see how long it would take,
it got to the final loading of vmunix, and then failed. but, it took only 
3 min 27 seconds to compile everything! 8-)

it needs a good bit more work to be quite right. for instance, without
inserting the halts in srt0.c right before it calls configure() in the 
standalone code, it bombs with an SCB ERR2, and without a halt in 
tmscpprobe(), it similarly barfs, with evidently an interrupt that is not
properly serviced.. with the halts, (thanks to ragge who pointed this out
to me) the PSL gets restored to normal and i dont get access violations
trying to run on the interrupt stack.. since the halt is a software thing
on this machine.. 
still.. cause for a small cheer that it actually booted. next to find out 
how to fix these probelms that _sort_ of get fixed by the halts.. 

happy hacking,
isildur

-----------

>>>b dua0
(BOOT/R5:0 DUA0)

  2..
-DUA0
  1..0..


?06 HLT INST
        PC = 0015007F
>>>c
in configure..
in configure, doing ka680 things..
loading boot
uda.c: isildurean check

?06 HLT INST
        PC = 0015007F
>>>c
in configure..
in configure, doing ka680 things..
isildurean checking.. we're in boot.c

Boot
: /vmunix
uda.c: isildurean check
205056+78716+63060 start 0x1554
4.3 BSD UNIX #85: Sat Jul 14 02:11:36 EDT 2001
    isildur@osgiliath:/usr3/build/sys/MLUIN
real mem  = 67059712
SYSPTSIZE limits number of buffers to 103
avail mem = 64714752
using 103 buffers containing 843776 bytes of memory
VAX 4000/600, ucode rev 2
ioaccess: physa 20080000 pte 80038f88 size 194
probeqbus: numuba is 0
ioaccess: physa 20088000 pte 80038168 size 7c0
ioaccess: physa 30000000 pte 80038568 size 3e000
ioaccess: physa 20000000 pte 80038d28 size 2000
set vector to 1fc, uba_hd is 80050dac, numuba 0

?06 HLT INST
        PC = 8002E227
>>>c
>tmscpaddr tmscpsa b40  8031ad42
>setting to 9bff
>tmscpaddr tmscpsa 0  8031ad42
tmscpaddr tmscpsa 109b  8031ad42
tmscp0 at uba0 csr 174500 didn't interrupt
set vector to 1f8, uba_hd is 80050dac, numuba 0

?06 HLT INST
        PC = 8002E227
>>>c
>tmscpaddr tmscpsa b40  8031ad42
>setting to 9bfe
>tmscpaddr tmscpsa 0  8031ad42
tmscpaddr tmscpsa 109b  8031ad42
tmscp0 at uba0 csr 174500 didn't interrupt
uda0 at uba0 csr 172150 vec 764, ipl 14
uda0: version 6 model 13
uda0: DMA burst size set to 4
ra0 at uda0 slave 0: Wren-7, size = 2031704 sectors
dhu0 at uba0 csr 160440 vec 300, ipl 17
Yowzers! memory error!
Automatic reboot in progress...
Sat Jul 14 02:58:05 EDT 2001
Unknown error in reboot
erase ^?, kill ^U, intr ^C
# cd etc
# cat fstab
/dev/ra0a:/:rw:1:1
# cat >>fstab
/dev/ra0e:/usr:rw:1:2
# cat fstab
/dev/ra0a:/:rw:1:1
/dev/ra0e:/usr:rw:1:2
# Sat Jul 14 02:58:38 EDT 2001
checking quotas: done.
starting system logger
preserving editor files
  
clearing /tmp
standard daemons: update cron accounting.
starting network daemons: routed named inetd printer.
starting local daemons: sendmail.
Sat Jul 14 02:58:48 EDT 2001


4.3 BSD UNIX (mindolluin) (console)

login: isildur
Password:
Last login: Sat Jul 14 02:10:22 from umbar.pgh.nx
4.3 BSD UNIX #85: Sat Jul 14 02:11:36 EDT 2001

Welcome to osgiliath, Lord Isildur's VAX UNIX timesharing system.

happy hacking!

bash$