Observations And Comments On 750 Bsd Installation

[Perry Kivolowitz]

We at Stony  Brook recently installed 4.1Bsd on the first of a bunch of
750's. We would like to take this opportunity to share a little of what
we learned in the hopes that we can save someone (anyone!) some  grief.

First:	 The version of 4.1 we installed has a revision date of Sept 1,
1981.

Second:	The configuration.

	Vax 750.
	2Mbytes Memory.
	Floating Point Board (although  this  shouldn't  enter into the
		following discussion).
	Uda50 Disk Controller.
	DZ 11's.
	TU-80 - (man, oh man, if ever  there  was a tape drive intended
		for PATIENT people.)

	RL11  - with an rl02.
	RA80  -
	RA81  .

________________________________________________________________________
              TROUBLE GETTING BERKELEY BOOTSTRAP TO WORK.
------------------------------------------------------------------------

The TU-80  will work from a TS-11 bootstrap (and driver). We immediately
ran  into  problems in getting the Berkeley bootstrap to work. The first
problem turned  out  to  be a schiz'ed cpu board which would run the VMS
16   user   simulator  (UETP)  but    failed  its  basic instruction set
diagnostics (you figure it out). The second problem is that DEC normally
sets the UDA-50 device  address  to 0772150. The Berkeley bstrap expects
this to be 0777550.

Solution: Have DEC install the UDA-50 at 777550 (or do it yourself).
________________________________________________________________________
                     NO BOOTSTRAP FOR THE UDA-50.
------------------------------------------------------------------------

We currently face this problem by hoping we don't  have  to  reboot. One 
day, some  kind  soul  will  send  us  one (hint!) We didn't receive any 
UDA-50 programming spec's so writting the bstrap ourselves is out of the
question.

________________________________________________________________________
                         NO DRIVER FOR THE RL02
------------------------------------------------------------------------

Who cares. (But if someone happens to have one...)

________________________________________________________________________
    NO SUPPORT (READILY) AVAILABLE FOR MULTIPLE DRIVES ON THE UDA-50
------------------------------------------------------------------------

The UDA-50   driver   we   received  had  knowledge  of  the RA-80 only. 
Moreover, it dealt  with  only  a  SINGLE RA-80. Luckily, the hooks were 
there to add  multiple drive support as well as adding a second level to
the partition size data structure.

If anyone wants this - send mail. BUT - it really wasn't much trouble to
do (about twenty minutes).

------------------------------------------------------------------------
       YES!!!! JUST COMMENT OUT N_DH and DH11 FROM SYMBOLS.RAW
------------------------------------------------------------------------

Nuff said.

------------------------------------------------------------------------
                                TU-80
------------------------------------------------------------------------

The TU-80 is great fun. Get one and hope for lots of rainy days. You can
cheer and take bets on when it'll find the beggining of tape mark. Also,
hire a grunt to make believe he's an automatic on-line feature.

________________________________________________________________________
                         IT RUNS NOW - BUT...
------------------------------------------------------------------------

o	If you ever get into a situation where Unix wants to do  a  core
	image save  to  disk  (after  a crash, for instance) there is no
	UDA-50 DUMP routine (as noted in a previous letter  to this news
	group).

o	SIT DOWN - Take a deep breath:

	With a 1K blocking  granularity  (Cluster  setting 2 in param.h)
	block i/o on the UDA-50 takes place at a blinding 20 to 30Kbytes
	per second. (You did not read that wrong - I DID say 20 to 30  K
	bytes per second).

	We took measurements which showed that we could achieve:

			(ALL ON RAW DEVICE)

		453Kb/sec with 64Kb transfers.

		192Kb/sec with 4Kb transfers.

		and 29Kb with 512 byte transfers.

	What can be done? Well, the file system  data  structure  allows
	one more increment in the blocking factor - to 2048 byte units).
	Adopting this will help a tad but cost in fragmentation.

	We expect that the problem is  due  to  having  to pay the piper 
	each  time we grab the Unibus. We believe that an entire rewrite
	of the  uba  code is on order as the driver was probably written
	before the 750  was  on  the scene (ie - Hey we have a Massbus -
	Why fiddle with that ol'Unithingy).

	We are working on this (but we don't want to).

------------------------------------------------------------------------
                                SUMMARY
------------------------------------------------------------------------

	We  are  firm  in  our  belief  that  a  Vax is a great personal 
	workstation.


________________________________________________________________________
				 ETC
------------------------------------------------------------------------

	Noone that we could find  at  Berkeley  knew how to regen a boot 
	tape  (ie  the  stand  alone system's tape directory structure).
	Any clues?

------------------------------------------------------------------------

	Hope this helped someone somewhere.


						Perry S Kivolowitz
						Rick J Spanbauer

						SUNY/Stony Brook
						allegra!sbcs!perry
						philabs!sbcs!perry

						(516) 246-7146
						so there!