BRACKENRIDGE@USC-ISIB.ARPA (05/27/85)
From: Billy <BRACKENRIDGE@USC-ISIB.ARPA>
The following is the result of some investigative reporting on my
part on behalf of info-ibmpc. A few weeks ago Xerox announced a new
processor called the 6085 PCS (Professional Computer System). It
includes something called the PC Option. As editor of info-ibmpc this
looked interesting to me so I sent a message off to the Xerox
internal IBM-PC distribution list asking for more information. From
phone conversations, computer mail, and published Xerox literature, I
have collected a great deal of information on this machine. My
initial interest in the 6085 was because of the PC option, and that
was the thrust of my article in info-ibmpc. WORKS is a more
appropriate forum for the more general discussion of the 6085 work station.
Much of the following is lifted from messages from Abdo Kadifa
published in info-ibmpc. Abdo Kadifa is a member of the "Rainbow
Coalition" at Xerox. Thanks to Abdo and many other members of the
Rainbow Coalition. If there are any errors in fact they are introduced
by myself as a product of the editing process. I am sure people from
Xerox will be ready to respond to clarify the facts.
The Xerox 6085 is a high performance, single user workstation capable
of running an integrated software system based upon the Xerox
ViewPoint software package. It provides a 32-bit 8 MHz Mesa processor
engine designed for efficient execution of large-scale, modular
programming systems. This engine is implemented with 2901 bit slice
hardware and like its predecessor the Dandelion features loadable
microcode. Data fetches are 16 bits wide and there are 24 bits of
address space stored in a 32 bit double word. ViewPoint provides the
underlying system structure and a powerful window package as well as
the framework for running the Xerox VP Series applications packages.
The machine in its base configuration comes with a 15" monochrome
display. (880 x 697 resolution) There is also a 19" monochrome
option. The 6085 does everything that the Dandelion does, the
physical unit itself is a smaller box than the Dandelion and it has a
smaller fan and, thus, is quieter.
The 6085 with a 10 MByte rigid disk is roughly 10% faster than a
Dandelion with a 42 MByte drive. Other options currently planned for
support, and mentioned in the literature, are 20, 40 and 80 MByte
rigid disk drives. The 10 MByte drive is the slowest of the drives
Xerox offers because it uses a stepper motor. Whereas, the larger
drives use servo-motors. 30 MByte and 40 MByte drives in a 6085
perform roughly 8-15% better than the 10 MByte drive. Since the
rigid disks used in the 6085 are 5.25" drives the average seek delay
is shorter due to the fact that there is less travel on the disk arm.
This all adds up to increased performance of the new machine over the
Dandelion. Also, the fact that the Mesa processor in the 6085 does
not have to time-slice the central processor with the high-speed I/O
devices (Ethernet, Display, and rigid disk) means that Xerox can get
better performance for compute-bound tasks. One other difference
between the Dandelion and the 6085 is the fact that Xerox has
upgraded to an Intel 80186 for the I/O Processor (IOP) from the Intel
8085 on the Dandelion. The Intel 80186 is a faster processor and has
a richer instruction set. The rigid disk, further has a microcode
disk controller and special hardware between the disk sub-system and
main-memory which allows full-speed concurrent operation between the
Ethernet, the rigid disk and any other I/O that may be occurring.
(The information in this paragraph is subject to change.)
In short, the pure processing capabilities of the IOP in the 6085
Professional Workstation are superior to those in the Dandelion;
however, one has to take into account that the IOP in the 6085 now
handles all of the I/O and not just the low-speed I/O devices.
ViewPoint is the windowing environment upon which applications sit.
This architecture is different from Star in that it is open, allowing
application developers to plug-in their own applications. It also
provides multiple overlapping windows, whereas Star allowed at most 6
tiled windows.
The "VP Series" are the applications. For instance, some of the
applications provided are "VP: Document Editor", "VP: Freehand Drawing",
"VP: Terminal Emulations", "VP: PC Emulation". These applications are,
for the most part, Star applications which have been modified to take
advantage of ViewPoint. There are also some new features added to each
application, as well as new applications like Freehand Drawing.
Xerox claims to be committed to an open architecture. You can currently
program the new 6085, as well as the Dandelions, through the Xerox
Development Environment (XDE). This consists of the Mesa compiler and
a set of general tools, such as those for electronic mail, remote and
local filing, printing, communications and maintenance. XDE is
available commercially and can be purchased from Xerox. Xerox made a
grant of a value of 13 million dollars to several leading
universities (I think the total number was 12) in the form of Dandelions,
file servers etc. XDE was also provided for software development.
I assume the 6085 will take over as Xerox's standard processor. I
further assume that the Interlisp, Smalltalk, Japanese and Chinese
word processors, and Versatec CAD software have also been ported to
the 6085. I haven't seen any announcements in these areas, but they
can't be far off.
My initial interest in this machine was because of the PC option.
This is a SECOND 80186 processor board and ViewPoint software that
provides an IBM-PC Icon on the ViewPoint desk top. For more details
see info-ibmpc digest V4 #61,#62,#63
The PC Option will first appear on the desktop of the 6085 as an icon
that has the form of an IBM PC. When you select the icon and open it, a
property sheet will appear, where you can specify the following:
(1) Disk drive configuration: N Floppy drives (One real and up to three
emulated as icons) and/or one rigid disk. A real floppy is a 5 1/4 in.
floppy drive that is physically installed on the 6085 and has the same
physical characteristics of an IBM PC. Therefore, you can, for example,
insert a Lotus diskette in this drive and boot the PC window, hence you
get Lotus running in the window like in the normal PC.
(2) Display type: Monochrome, 40-col Color/Graphics, 80-col
Color/Graphics. ( Just IBM hardware options at this stage)
(3) Memory size: From 128 KB to 640 KB in 128 KB increments
(4) Misc.: printers, option boards, etc.
All the above options are done through software, hence when you change
your memory size, the operating system will map more (or less) memory
for the PC Option without adding memory boards and powering the system
down.
After specifying your PC configuration in the property sheet, you can
boot the system and the property sheet will be replaced by a full size
PC window. MS-DOS is booted if the floppy drive contains an MS-DOS
system diskette, and you can run any program you want by inserting it in
the drive or running it from the net if it happens that you have it
stored on a file server.
The PC Option processor board has no I/O capabilities of its own. All
the access to the outside world are through the 6085 processor and
its attached 80186. When software on the PC Option board reads or
writes to an I/O port or to display memory. It is actually writing to
the 6085 processor which then simulates the appropriate device. Thus
your virtual PC clone can have either a monochrome or color adapter
display without having either. Xerox has protected themselves from
obscolesence as they should be able to emulate most any sort of
display interface. Similarly the keyboard can easily be simulated by
the 6085. Xerox is also claiming to simulate the serial port at the
hardware level. Very few IBM clones go this far (only the successful
ones). I will have to try Kermit or VDTE before I accept this claim.
The 6085 with PC Option will come with MS-DOS but it should run other
operating systems as well. Xerox purchased BIOS from one of the
companies that specializes in this area so the machine is BIOS
compatible. I don't know if there is actual ROM or the BIOS just runs
from write protected memory. The latter would be a nice feature. I
don't know whether operating systems such as PC/IX which bypass BIOS
will run, but I wouldn't be surprised.
The initial reaction of most people to this system is "but it doesn't
have an IBM PC bus. It will never be successful." My response has
been "Tell me what hardware you want and I will implement it in Mesa
code." For example the new INTEL/LOTUS or Tall Tree page mapped
memory cards should be relatively trivial additions. Something like a
professional graphics adapter would be more difficult, but possible
to implement as mesa and special microcode in the 6085 processor. I
wonder if Xerox has done an AST clock calendar. This hardware
configuration could really take off if Xerox published enough
technical specifications that third parties could write emulations
for popular devices.
I have heard of a very large APL application which has run on the
6085 with no conversion effort involved.
I was very concerned that the PC Option would be unable to run
communications software. I have been assured that the serial port on
the PC will accurately simulated by the 6085 and that the 3Comm
Ethernet interface will also be simulated. The 3Comm interface,
however, probably won't be available at the initial release.
Pricing:
$4995 6085 basic system (10Mb disk, 1.1 Mb memory,
keyboard/display/optical mouse) The display is 15"
pixel dimensions: 880 x 697
$995 PC Option (hardware AND software for PC Emulation).
$125 ViewPoint software (basic window environment/operating system)
VP Series applications (applications software written by Xerox for
ViewPoint) range from $35 to $995.
This looks like a very interesting machine and the price is right. I
think the PC option and lower price will help sell processors in
large corporations where Xerox is the only player in the distributed
business systems market.
As a researcher anything which isn't unix and doesn't require C code
is a big plus as far as I am concerned. The PC options window, if the
communications options work is very handy. I am satisfied Xerox did a
great job making this a truly compatible and thus useful option. The
big unknown is the Xerox Development Environment. Several projects at
ISI have been running in this environment for more than 3 years. Some
have quit in disgust and others have moved to Interlisp in order to
do some something useful with their Dandelion processors. The
researchers at Parc have always been very cooperative, but the
corporate types have made any progress impossible while providing
full employment for USC's lawyers. This new offering is full of more
claims that Xerox is back in the computer business, and we have an
open architecture, but I would warn anyone in the research community
who views this as a potential computer science work station to make
clear where the "Open Architecture" ends and "Xerox Proprietary" begins.e the "Open Architecture" ends and "Xerox Proprietary" begins.
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