parker@ucbvax.UUCP (Allene M. Parker) (06/09/84)
BS ANNOUNCEMENT
We have completed Beta-testing and we are ready to distribute the
Berkeley Smalltalk-80 Virtual Machine II (BS II) on SUN 2s. This is Dave
Ungar's second implementation of BS, as it is affectionately known. It is
written in C, runs under 4.2 BSD UNIX on SUN 2's, and needs 2 megabytes of
physical memory. According to the Smalltalk-80 benchmarks, BS II runs
about the speed of the Xerox Dolphin. Ungar built BS II as part of our
research in building a VLSI computer to run Smalltalk-80, which we call
SOAR (Smalltalk On A RISC).
We will list several reasons why you wouldn't want BS II and a few
reasons why you might want it, before telling you how to get a copy.
The Disadvantages of BS II:
(1) BS II is slower than the Dorado. You should not expect too much from
BS II. The only machine that everyone agrees has adequate Smalltalk-
80 performance is the Dorado, it runs at least 10 times faster than BS
II on the SUN 2. (It costs a bit more too.)
(2) BS II does not run on a VAX. We have abandoned our VAX version of BS,
so if you want to discover for yourself that timesharing Smalltalk is
no fun, you will have to take the C programs and port it yourself.
Good luck! You will also have to port it yourself if you have a SUN
0, SUN 1, Masscomp, Apollo, and so forth. (In case you are curious,
you would have to change all the graphics and input routines , about
10% of BS II.)
(3) There is no support. We have used BS II at Berkeley and we believe it
is relatively stable. It is unlikely, however, that it is perfect.
The Advantages of BS II are:
(1) BS II has 32-bit OOPS and Virtual Memory: BS II allows much larger
Smalltalk-80 applications than can be run on the Dolphin. The current
Smalltalk-80 system is straining at the limits of the 16-bit pointer.
(2) BS II is Written in C for Portability and Readability: The only sys-
tems that are faster than BS II are written in microcode or in assem-
bly language. Thus BS II can be ported to different machines. BS II
is also a much more efficient virtual machine than the description
found in The Book. If you are going to ``roll your own'' virtual
machine, you have a much better chance of a fast implementation is you
look at BS II.
(3) BS II Runs with UNIX. BS II runs on top of UNIX, so you can go From
Smalltalk To UNIX And Back with relative ease.
(4) The Price is Right. We are distributing the virtual machine for free
to universities and government laboratories. (We ask companies to make
a donation.) As you probably know, you must get the Smalltalk-80
source ("image") from Xerox. The Smalltalk-80 image costs $400 for
universities and $20,000 for companies. Contact Duane Bay
(Bay.PA@Xerox or 415-494-4396) for more information. We supply a vir-
tual machine that can run the image.
After weighing the advantages and disadvantages of BS II, if you
decide you would like a copy, contact Allene Parker
(parker%ucbernie@Berkeley, ...!ucbvax!ucbernie!parker, or 415-642-5399) for
the full announcement (including benchmarks) and copies of the letters.
Dave Patterson