[comp.arch] PC/AT clones with RISC cpu

pcg@aber-cs.UUCP (Piercarlo Grandi) (11/01/90)

On the subject of a SPARC based PC/AT clone:

somebody> It is fairly cheap (starting prices ~$4999).

In article <P0R6UO2@xds13.ferranti.com> peter@ficc.ferranti.com (Peter
da Silva) writes:

peter> Sorry. That's not "fairly cheap". That's not even "moderate". AT
peter> bus machines with 386es in them start under $2000.

On 30 Oct 90 15:45:04 GMT, davidsen@crdos1.crd.ge.COM (Wm E Davidsen Jr) said:

davidsen> Not with 4MB, FPU, ethernet, and 1152x900 displays, they
davidsen> don't. These are aimed for a totally separate market. I
davidsen> haven't tested one yet, but on paper they will produce better
davidsen> cost/performance than the Sun SS+, at least at list price.

Not to mention an open architecture, with the ability use hundreds of
low cost accessories. But the $4999 really ought to include an hard disk
(say, 80MB ESDI 20msec.) to be competitive with a Sun SLC -- also the OS
may not be included.

davidsen> 25MHz SPARC, FPU, MMU, 64 bit memory path, 64k cache. Color,
davidsen> harddisk, 386, and thinnet are options.

Incidentally, my MIPS PC/AT idea was based on seeing an advert in EDN
for an R3000/R3010 evaluation module that with 64K cache and 128K SRAM
would cost something like $895. This looks expensive, but still it is
significantly less than an i486, or an i386+i387+cache controller, and
gives about the same performance (it is actually better than a 486 on
floating point, as John Mashey keeps telling us).

I have no doubt that a MIPS or SPARC or AMD 29k or M88k based CPU module
should cost significantly less than an i486. Could anyone with an idea
of list prices for quantities like 100 pieces give us an idea of the
cost of a CPU module (CPU, FPU, MMU, minimum effective cache) for each
of the above architectures?

Can anybody tell us how difficult it would be to design a plug in board
for an i486 socket with any of the above chip designs? (I expect this
to be hard).

	Note: i486 motherboards, without the 486, are not much more
	expensive than 386SX ones. Get my drift?

Can anybody tell us how difficult it would be to redesign an existing
i[34]86 based motherboard around each of the aboved chip designs? (I
expect this to be not that difficult, but not easy either).

And so on...


-- 
Piercarlo "Peter" Grandi           | ARPA: pcg%uk.ac.aber.cs@nsfnet-relay.ac.uk
Dept of CS, UCW Aberystwyth        | UUCP: ...!mcsun!ukc!aber-cs!pcg
Penglais, Aberystwyth SY23 3BZ, UK | INET: pcg@cs.aber.ac.uk

davidsen@crdos1.crd.ge.COM (Wm E Davidsen Jr) (11/01/90)

In article <2081@aber-cs.UUCP> pcg@cs.aber.ac.uk (Piercarlo Grandi) writes:

| 	Note: i486 motherboards, without the 486, are not much more
| 	expensive than 386SX ones. Get my drift?

  I don't know about in thousands, but I have been looking hard at
boards for my project cheap-ix, and the SX boards with CPU are about
$350 in Q5, the 486 $900-1500 Q5, without CPU. Allowing $150 for the SX
chip (I can't find anyone selling them separately in the pile I have
handy), that would make the board about 4x more expensive.

  I think the use of 32 bit paths, more expensive bus control chips, and
more layers in the board to keep it reliable at higher speeds account
for this.

  Note that this is not to agree or disagree, because I think you could
argue that the price diference is what counts rather than the ratio, and
the ratio in a complete system price would be only 10-20% increase.
-- 
bill davidsen	(davidsen@crdos1.crd.GE.COM -or- uunet!crdgw1!crdos1!davidsen)
      The Twin Peaks Halloween costume: stark naked in a body bag

sysmgr@KING.ENG.UMD.EDU (Doug Mohney) (11/01/90)

In article <2081@aber-cs.UUCP>, pcg@aber-cs.UUCP (Piercarlo Grandi) writes:
>On the subject of a SPARC based PC/AT clone:

Well, heck with that! How much trouble would it be to build a PC-clone which
could double as an X-term? I'm talking about a one-piece board with built-in
Ethernet and 2MB of RAM, and a '386, add a couple sockets for ROMs. 

You crank many of them out in Taiwan, sell them as dirt-cheap clones, or add
the ROMs and a high-res monitor and you have Mr. X-term....

I guess the best bet would be a modified PC-clone, with the built-in Ethernet,
some support for a local disk, and an option to replace/toggle-between the
ROMs for bootup. 

jonah@dgp.toronto.edu (Jeff Lee) (11/02/90)

sysmgr@KING.ENG.UMD.EDU (Doug Mohney) writes:

>Well, heck with that! How much trouble would it be to build a PC-clone which
>could double as an X-term? I'm talking about a one-piece board with built-in
>Ethernet and 2MB of RAM, and a '386, add a couple sockets for ROMs. 
 [...]
>I guess the best bet would be a modified PC-clone, with the built-in Ethernet,
>some support for a local disk, and an option to replace/toggle-between the
>ROMs for bootup. 

A group here is tossing around a similar idea, but minus the disk
controller and (possibly) plus a SCSI port, with SIMMs for memory
(1/4/16MB).  However, we're considering a RISC processor in place of
the 386 (running at memory speeds to eliminate the cache and reduce the
chip count).  Does anyone working on current small systems design have
any suggestions on how easily [i.e using little glue] current
processors (29K, 88K, MIPS, SPARC, or even [34]86, 680[34]0, or ???)
would or would not fit into such a low-chip count, low-end,
low-quantity(?) product?  Also, how easy is it to add an FPU along
with those chips that don't include it?

Alternatively, does anyone know of an existing board-level product
with at least >=1M pixel memory mapped graphics, CPU,
keyboard/mouse/serial ports, EPROM socket(s), and >=2MB RAM?
Ethernet, SCSI, FPU, and TOD-clock are optional, but full hardware
documentation is essential.

Jeff Lee -- jonah@cs.toronto.edu || utai!jonah

torbenm@freke.diku.dk (Torben [gidius Mogensen) (11/02/90)

jonah@dgp.toronto.edu (Jeff Lee) writes:

>sysmgr@KING.ENG.UMD.EDU (Doug Mohney) writes:

>A group here is tossing around a similar idea, but minus the disk
>controller and (possibly) plus a SCSI port, with SIMMs for memory
>(1/4/16MB).  However, we're considering a RISC processor in place of
>the 386 (running at memory speeds to eliminate the cache and reduce the
>chip count).  Does anyone working on current small systems design have
>any suggestions on how easily [i.e using little glue] current
>processors (29K, 88K, MIPS, SPARC, or even [34]86, 680[34]0, or ???)
>would or would not fit into such a low-chip count, low-end,
>low-quantity(?) product?  Also, how easy is it to add an FPU along
>with those chips that don't include it?

Try looking at the ARM (Acorns Risc Machine) chip set, produced by
VLSI technology.

The ARM is a 32bit RISC cpu, currently found in two versions, ARM2 and
ARM3. It sounds like the ARM2 is best suited for your purpose, as it
is without cache and designed to work fast even so. There are
currently 3 support chips: MEMC, VIDC and IOC. MEMC is a memory
management unit, VIDC is a video and sound controller and IOC is an
I/O controller.

VIDC is able to support memory mapped dispalys with virtually any
resolution in up to 8 bits per pixel. It is programmable regarding
frequency, and can be used on both normal frequency monitors, VGA
monitors, multiscan monitors and high frequency monitors. Acorn
computers have produced computers and workstations that support all of
these types of monitors on the same machine.

Prentice Hall publish the book:
	"VL86C010 32bit RISC MPU and Peripherals Users Manual"
	ISBN: 0-13-944968-X

The book has the datasheets for:
	VL86C010 - ARM2
	VL86C110 - MEMC
	VL86C310 - VIDC
	VL86C410 - IOC

The present production version of MEMC is MEMC1a, which is an improved
version of the MEMC described in the book.

The cost of the complete chip set (ARM2, MEMC1a, VIDC and IOC) is
lower than the price of a 386.

The ARM3 is an ARM2 expanded with cache plus a few syncronisation
commands. It is currently available in versions running up to 40MHz.

Acorn has announced an FPU, supposed to be shipping at the end of the
year.

>Alternatively, does anyone know of an existing board-level product
>with at least >=1M pixel memory mapped graphics, CPU,
>keyboard/mouse/serial ports, EPROM socket(s), and >=2MB RAM?
>Ethernet, SCSI, FPU, and TOD-clock are optional, but full hardware
>documentation is essential.

Acorn sells full machines with the above specifications, but I do not
think they sell boards only. The top level products are UNIX
workstations supporting screen modes of 1152x900 B/W uning a high
frequency monitors or 800x600x256 colours using super VGA monitors.

>Jeff Lee -- jonah@cs.toronto.edu || utai!jonah

Torben Mogensen (torbenm@diku.dk)

sysmgr@KING.ENG.UMD.EDU (Doug Mohney) (11/02/90)

In article <1990Nov2.000650.18866@jarvis.csri.toronto.edu>, jonah@dgp.toronto.edu (Jeff Lee) writes:

>>I guess the best bet would be a modified PC-clone, with the built-in Ethernet,
>>some support for a local disk, and an option to replace/toggle-between the
>>ROMs for bootup. 
>
>A group here is tossing around a similar idea, but minus the disk
>controller and (possibly) plus a SCSI port, with SIMMs for memory
>(1/4/16MB).  However, we're considering a RISC processor in place of
>the 386 (running at memory speeds to eliminate the cache and reduce the
>chip count). 

Doesn't count :-) PC compatability (for better or worse) and decent X-term
capability would be more better. I suppose you could be really perverted, use a
RISC processor and stick in Soft-PC in ROMs. Flip a switch and that $2000+
X-term becomes a $1000 PC-clone. Aw nuts, you'd still need to throw in a disk
controller for a 3 1/2" floppy, and you'd probably have to hack the Soft-PC
up a bit to support SCSI disk storage. 

>Does anyone working on current small systems design have
>any suggestions on how easily [i.e using little glue] current
>processors (29K, 88K, MIPS, SPARC, or even [34]86, 680[34]0, or ???)
>would or would not fit into such a low-chip count, low-end,
>low-quantity(?) product?  Also, how easy is it to add an FPU along
>with those chips that don't include it?

You might wanna look at how the SparcStation SLC was put together; I understand 
there are a couple of companies offering up glue chip-sets for Sparc.

henry@zoo.toronto.edu (Henry Spencer) (11/03/90)

In article <0093F1A8.A28E4920@KING.ENG.UMD.EDU> sysmgr@KING.ENG.UMD.EDU (Doug Mohney) writes:
>Doesn't count :-) PC compatability (for better or worse) and decent X-term
>capability would be more better...

Some people would consider neither a virtue. :-)  Both are de-facto standards
that are hideously ugly and do terrible things to your system design if you
enshrine them as fundamental goals.  (Retaining the potential for them, on
the other hand, is easy:  any fast CPU with a large address space can
emulate the early Intel processors at higher speed than Intel chips, and
X is not difficult to port to a sane machine with a clean frame buffer.)

>...use RISC processor and stick in Soft-PC in ROMs...

A small practical difficulty with this approach is that Soft PC is licensed
software.  It also does a less than wonderful job of emulation, as our
department is finding out on a bunch of DEC RISC workstations for undergrad
teaching...

>You might wanna look at how the SparcStation SLC was put together; I understand 
>there are a couple of companies offering up glue chip-sets for Sparc.

The two parts of this sentence are unrelated. :-)  I haven't seen details
on the SLC, but Sun normally uses proprietary MMU designs that bear no
relation to (e.g.) the "Sparc Reference MMU".  Worse, not only are they
proprietary but they are Top Secret, although apparently Sun has entirely
forgotten why, since they can't offer any rational reason for it when
asked.
-- 
"I don't *want* to be normal!"         | Henry Spencer at U of Toronto Zoology
"Not to worry."                        |  henry@zoo.toronto.edu   utzoo!henry

rick@ameristar (Rick Spanbauer) (11/03/90)

In article <1990Nov3.052952.1786@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes:
>The two parts of this sentence are unrelated. :-)  I haven't seen details
>on the SLC, but Sun normally uses proprietary MMU designs that bear no
>relation to (e.g.) the "Sparc Reference MMU".  Worse, not only are they
>proprietary but they are Top Secret, although apparently Sun has entirely
>forgotten why, since they can't offer any rational reason for it when
>asked.

	It may be a simple reason, like not wanting users to be able to buy 
	only SunOS tapes from Sun and then run the binaries on cheap sparc 
	clones, or to make the job of clone companies harder (ie buy a SunOS 
	sources + unix guru to rewrite the MMU code). Suns choice of what they 
	consider trade secret has never been very user friendly at all - for 
	years, one couldn't get schematics, buy keyboard and power supplies 
	directly from their suppliers, get compiler, rasterop lib, ND, or MMU 
	source, etc.  We tend to pay more for our Suns, yet know less about 
	them than our Amigas, PCs, or Macs :-)  

>"I don't *want* to be normal!"         | Henry Spencer at U of Toronto Zoology

					Rick Spanbauer
					Ameristar

sysmgr@KING.ENG.UMD.EDU (Doug Mohney) (11/04/90)

In article <1990Nov3.052952.1786@zoo.toronto.edu>, henry@zoo.toronto.edu (Henry Spencer) writes:
>In article <0093F1A8.A28E4920@KING.ENG.UMD.EDU> sysmgr@KING.ENG.UMD.EDU (Doug Mohney) writes:
>>Doesn't count :-) PC compatability (for better or worse) and decent X-term
>>capability would be more better...
>
>Some people would consider neither a virtue. :-) 

Well, neither is the United States Congress, but we have to work with the
systems which are installed, eh? ;-)

> Both are de-facto standards
>that are hideously ugly and do terrible things to your system design if you
>enshrine them as fundamental goals.  (Retaining the potential for them, on
>the other hand, is easy:  any fast CPU with a large address space can
>emulate the early Intel processors at higher speed than Intel chips, and
>X is not difficult to port to a sane machine with a clean frame buffer.)

People will want X-terms and people will want PC-compatability. It is probably
easier to build a PC with 1024 x 768 monitor, and be able to drop in a couple
of bootstrap ROM which access your (built-in) Ethernet to load up the
X-software.

Of course, you could insist upon Token Ring as well, but I'm hoping it will go
away.  

I wouldn't do this with anything less than a '386; you can keep the
"earlier" Intel processors. Since AMD and others are coming out with '386
clones, the chip count would be pretty small.

>>...use RISC processor and stick in Soft-PC in ROMs...
>
>A small practical difficulty with this approach is that Soft PC is licensed
>software.  It also does a less than wonderful job of emulation, as our
>department is finding out on a bunch of DEC RISC workstations for undergrad
>teaching...

I said this was perverse. I didn't say it was optimized. I noted it would
require some hacking to get it running properly.

>>You might wanna look at how the SparcStation SLC was put together; I understand 
>>there are a couple of companies offering up glue chip-sets for Sparc.
>
>The two parts of this sentence are unrelated. :-)  I haven't seen details
>on the SLC, but Sun normally uses proprietary MMU designs that bear no
>relation to (e.g.) the "Sparc Reference MMU".  

So? I don't think Sun has patended the way they use board real estate. See how
they did things (Board in the back of the monitor <hm. What will all those
zappo evil EM rays coming out the back to do the chips in the long run?>, small
configuration). Go get the commercial Glue chips and go to town.

			Doug

henry@zoo.toronto.edu (Henry Spencer) (11/04/90)

In article <0093F295.10626840@KING.ENG.UMD.EDU> sysmgr@KING.ENG.UMD.EDU (Doug Mohney) writes:
>People will want X-terms and people will want PC-compatability...

By this reasoning, nobody should be building anything except PC-compatible
X terminals.  Strangely, many manufacturers manage to make money building
machines that are neither.
-- 
"I don't *want* to be normal!"         | Henry Spencer at U of Toronto Zoology
"Not to worry."                        |  henry@zoo.toronto.edu   utzoo!henry

henry@zoo.toronto.edu (Henry Spencer) (11/04/90)

In article <1990Nov3.150202.27353@ameristar> rick@ameristar (Rick Spanbauer) writes:
>>... Sun normally uses proprietary MMU designs that bear no
>>relation to (e.g.) the "Sparc Reference MMU".  Worse, not only are they
>>proprietary but they are Top Secret, although apparently Sun has entirely
>>forgotten why, since they can't offer any rational reason for it when
>>asked.
>
>	It may be a simple reason, like not wanting users to be able to buy 
>	only SunOS tapes from Sun and then run the binaries on cheap sparc 
>	clones, or to make the job of clone companies harder...

I said "rational reason".  The problem with the idea of keeping it secret
from the competition is that it's not that hard to reverse-engineer the
stuff if you try.  The basic design concepts were published long ago; all
that is being kept secret is the details, exactly the sort of thing that
a competent engineering team could figure out in a month or two, given
a couple of machines to play with and modern tools.  Any would-be clone
company has ample resources to figure this stuff out without Sun's help.
This policy makes life harder only for the legitimate customers.

I can see keeping things like this secret *briefly*, when the machine is
new and hot and it's worth throwing up even small obstacles to the cloners,
but why are the MMU details of the Sun 2 still secret today?
-- 
"I don't *want* to be normal!"         | Henry Spencer at U of Toronto Zoology
"Not to worry."                        |  henry@zoo.toronto.edu   utzoo!henry

paul@taniwha.UUCP (Paul Campbell) (11/05/90)

In article <1990Nov3.235958.21976@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes:
>I can see keeping things like this secret *briefly*, when the machine is
>new and hot and it's worth throwing up even small obstacles to the cloners,
>but why are the MMU details of the Sun 2 still secret today?


Probably they are still embarassed by them ......


	Paul



-- 
Paul Campbell    UUCP: ..!mtxinu!taniwha!paul     AppleLink: CAMPBELL.P
What most people don't realize is that those plastic cover slips that your 3
inch floppies come in are actually condoms for protecting your computer from
harmfull computer viruses - practice safe computing ..... :-)

graeme@labtam.labtam.oz (Graeme Gill) (11/05/90)

In article <1990Nov3.235115.21250@zoo.toronto.edu>, henry@zoo.toronto.edu (Henry Spencer) writes:
> In article <0093F295.10626840@KING.ENG.UMD.EDU> sysmgr@KING.ENG.UMD.EDU (Doug Mohney) writes:
> >People will want X-terms and people will want PC-compatability...
> 
> By this reasoning, nobody should be building anything except PC-compatible
> X terminals.  Strangely, many manufacturers manage to make money building
> machines that are neither.

	From our experience I can say that Xterminal performance is limited by
by three things:
	
	1) For small operations, network bandwidth is the ultimate limit.
The x11perf poly point performance multiplied by 4 is usually a good estimate
of the available network bandwidth in bytes per second.

	2) For large areas, memory write speed is the ultimate limit. To get
good speed you need to take advantage of 32 bit access, burst writes, 
interleaved memory and any special write modes Vrams support.

	3) Between 1) and 2), performance depends on cpu speed. Small operations
area also fairly sensitive to instruction cache size, function call 
overhead and the working register set size. The more registers the processor
has the better, since graphics code is notorious for having large numbers
of function parameters, and a large number of working variables.

	Given the above considerations, the current PC/AT clones do not
measure up well. Their network interfaces are generally based on 16 bit
controller cards which shuffle data via small static ram buffers, limiting
network performance to (typically) 50 - 200 Kbytes/sec. This compares to
600 - 800 Kbytes/sec for a purpose built design. The common video cards
are accessible only 8 or 16 bits at a time, over the slow PC bus, and
may involve bank switching and plane wise access to pixels. Neither 286
nor 386/486 processors support burst write to memory.
	All these problems are reflected in the performance quoted for PC
X-terminal emulation - generally 10 to 100 times slower than purpose
built Xterminals and workstations. Hence the market for Xterminals -
workstation performance graphics on your desktop at a lower price.

	Graeme Gill
	Labtam I.S.D. Pty Ltd
	graeme@labtam.oz.au

davecb@yunexus.YorkU.CA (David Collier-Brown) (11/05/90)

davecb@yunexus.YorkU.CA (David Collier-Brown) writes:
>  Interestingly enough, there is at least one 68k-cpu pc around: the
>Institute of Space and Terrestrial Studies here at Ork helped develop
>a machine called the "lab 100", which is a small 68xxx-based system
>which uses at-style peripheral controllers and acessory boards, and fits
>in one of the small-footprint pc cases.  


  OOPS: that should have been Lab30!  Tyler Ivanco wrote back in
response to my posting and gave the specs, which include OS9 instead of
Unix, in part for its rtealtiem capabilities, in part for the ease of
writing device drivers...

Tyler writes:
| 	Well here I am out in Calgary reading about this box.  Actually,
| it is called the Lab30. Avy Moise at york (x55359) can show you the unit.
| Briefly:
| 
| 	16-20Mhz 030/FPU,
| 	High Speed SCSI,
| 	8 32/16/8 bit DMA channels,
| 		Any of the 8 channels can be "connected" to any request
| 		source.
| 	23+7 Vectored Interrupt channels,
| 	Series of high resolution timers,
| 	4MB on board DRAM,
| 	32KB SRAM,
| 	128KB EPROM,
| 	2 1Mbit serial channels,
| 	Real Time Clock,
| 	8/16 Bit AT bus (doesn't support bus master mode),
| 	LABus (just the 030 bus signals) to permit memory expansion,
| 		etc.
| 	Split board sandwich.  The PCB can be altered so that it can
| 		be cut in half and sandwiched thus reducing the footprint
| 		but about 50%.
| 	PC keyboard interface,
| 	OS/9 Real Time O.S. with support for the following:
| 		NI GPIB,
| 		SCSI H.D., Tape Drive, Optical Drive,
| 		Serial channels both on the motherboard and AT card,
| 		Real Time clock,
| 	 	Parallel port (on an AT card),
| 		General Purpose event card (custom design for one of our
| 						experiments).
| 	Device drivers in development:	
| 		Keyboard 
| 		floppy disk
| 		ATI VGA graphics
| 		OS/9 Windows 
| 		OS/9 Internet (via ethernet)
| 		AT Ethernet card
| 
| 
| 	Most of the work is real time based hence the reason for OS/9.  This
| 	O.S. is field proven and mature.  It is also easy to create, debug,
| 	and install device drivers.  The system can run without mass storage.
| 	Unix could be run on the system, but we have no plans to port as there
| 	are many other UNIX platforms out there that can do this job quite 
| 	nicely.
| 
| 	Anyway, hope that this help you.
| 
| 						Tyler
| 
| 	Talk to avy.  He can give you a more complete description.


  Alas, this tends to support both my and Henry's points (:-))

--dave
-- 
David Collier-Brown,  | davecb@Nexus.YorkU.CA, ...!yunexus!davecb or
72 Abitibi Ave.,      | {toronto area...}lethe!dave or just
Willowdale, Ontario,  | postmaster@{nexus.}yorku.ca
CANADA. 416-223-8968  | work phone (416) 736-5257 x 22075

rpeglar@csinc.UUCP (Rob Peglar) (11/05/90)

In article <1990Nov3.235115.21250@zoo.toronto.edu>, henry@zoo.toronto.edu (Henry Spencer) writes:
> In article <0093F295.10626840@KING.ENG.UMD.EDU> sysmgr@KING.ENG.UMD.EDU (Doug Mohney) writes:
> >People will want X-terms and people will want PC-compatability...
> 
> By this reasoning, nobody should be building anything except PC-compatible
> X terminals.  Strangely, many manufacturers manage to make money building
> machines that are neither.

Truth is stranger than fiction.

Henry's post reflects the fact (well, OK, generalization) that
	a)  the mass market (probably ~90 %) doesn't really know what
		they want - they buy what they're told, or what's "hot",
		or whatever they see in a magazine, or what's on sale,
		or ...  you get the point.  
	b)  the above-mentioned technology "PC-compatible X terminals" may
		be the "right thing" and all, but (most) companies exist
		to make money for the shareholders - not to spread "rightness"
		to the user base.
	c)  a) + b) means that marketing, not technology or architecture,
		dominates the "computer" business.  No one should be
		surprised.  Sad, perhaps, but not surprised.

Rob
-- 
Rob Peglar	Comtrol Corp.	2675 Patton Rd., St. Paul MN 55113
		A Control Systems Company	(800) 926-6876

...uunet!csinc!rpeglar

richard@aiai.ed.ac.uk (Richard Tobin) (11/06/90)

In article <1990Nov3.052952.1786@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes:
>Both [PC compatibility and X] do terrible things to your system design if you
>enshrine them as fundamental goals.  (Retaining the potential for them, on
>the other hand, is easy:  any fast CPU with a large address space can
>emulate the early Intel processors at higher speed than Intel chips, and
>X is not difficult to port to a sane machine with a clean frame buffer.)

I would be interested to hear you elaborate on this - in particular,
what does "enshrining X as a fundamental goal" involve other than
having "a sane machine with a clean frame buffer".

[Which reminds me: I was recently reading the "documentation" that
came with a super VGA board, and was disgusted to see that it can only
be addressed 128k at a time - you have to change banks by outputting
something to a port.  It occurred to me that this could all be hidden
behind the 386's paging; have a 512k area with only 128k mapped and
switch banks when you get a page fault.  Has anyone tried this?  Would
it be fast enough?  Followups to somewhere sane, please.]

-- Richard
-- 
Richard Tobin,                       JANET: R.Tobin@uk.ac.ed             
AI Applications Institute,           ARPA:  R.Tobin%uk.ac.ed@nsfnet-relay.ac.uk
Edinburgh University.                UUCP:  ...!ukc!ed.ac.uk!R.Tobin

phys169@canterbury.ac.nz (11/06/90)

In article <5530@labtam.labtam.oz>, graeme@labtam.labtam.oz (Graeme Gill) writes:
>> In article <0093F295.10626840@KING.ENG.UMD.EDU> sysmgr@KING.ENG.UMD.EDU (Doug Mohney) writes:
>> >People will want X-terms and people will want PC-compatability...
>> 
> [good reasons why PC's running X give very limited performance]
>
> 	All these problems are reflected in the performance quoted for PC
> X-terminal emulation - generally 10 to 100 times slower than purpose
> built Xterminals and workstations. Hence the market for Xterminals -
> workstation performance graphics on your desktop at a lower price.
> 
Still, the demand for PC-type equipment remains - e.g .where an organisation
has a big commitment to PC's already, or where stand-alone equipment is more
appropriate (ever try managing a bunch of Unix systesm, one-per-site, where the
users can barely manage DOS?).

So, if you can't make a good Xterminal out of a PC by adding software, how
about a replacement graphics card with Ethernet & 2nd CPU on-board?  That would
solve bandwidth problems and compatibility problems (given the right hardware
design).

My opinion is that now the "leading edge" of technology applies to a relatively
small number of users - before, when great improvements in speed came, every
computer user (from the home user up) could actually do with the extra
performance; now, there are becoming less and less buyers that actually need
that extra technology (although everyone will say it's nice). The "bread and
butter" for computer manufacturers will remanin with the majority of users in
offices and the like, where something like a PC is good enough. Power-hungary
programs may come along to raise the performance requirements a bit, but not
enough to justify the huge cost of R&D that an increasingly small section of
the market wants. Not that I, for one, think I have enough computer power at
the moment, but as more people start to realise they would be paying more for
power they don't need, they will be content to stick with (say) Asian
manufacturers turning out acceptable-performance machines using yesterday's
technology. This seems to be the real limit of growth, not bus bandwidth or the
speed of light.  

The one thing, other than performance, that grabs the "average" buyer (and
especially corporate buyers) is the fear of equipment becoming obsolete.
Curiously enough, this is working in favour of PC's and against Unix
workstations (when many would argue it ought to be the other way around). The
PC's have been here for such a long time, and the Unix-based workstation market
seems so volatile. Manufacturers of the latter (especially m88k-based ones,
according to the previous thread) should stop squabbling, and adopt some of the
PC-world stability and respectability, even if the (relatively small number of)
people who appreciate what's going on under the hood see the respectibility in
modern designs.  As I indicated above, you don't have to be saddled with all
the limitations of the PC standard, to accomodate PC users.

All this, of course, has a motive behind it; I've been wanting to buy some
workstations which will run X-windows, with good speed, and yet not loose
anything we had with 286-based PC's. Hopefully, some intelligent reader will
take to heart what I have said, and produce the workstation of my dreams, by
Christmas (which year?), please! :-)  It would have a 16" monochrome screen
with at least 32 shades (and accept any VGA mono/colour screen), an AT/VT220
compatible keyboard, rodent, optional diskette drive, 386 processor, RS232
and RS422 and parallel I-O on the motherboard, thin-wire Ethernet and multi
plane video card with 2nd (purpose-built) CPU on a single card, small box
(expansion can be via the network), and cost about the same as a conventional
big-box 386-based PC.

Okay, this isn't the place for wish-lists. The real point is, though, people
have different ideas of what an ideal workstation should be an do. It becomes
difficult to cater for all tastes, and still be competative. PC's have many
different screens, keyboards, and so on; manufacturers need not produce all
these themselves. It is tempting to say that X-windows compatibility is all
that is required, that what goes on inside the box isn't the user's concern.
Even now, X-terminals connected to a fast Unix box fail to give each user a
good PC emulator, for example, since only one person can use the computer
comfortably when that is running. Other people can probably think of good
reasons why the local workstation has to perform in its own right, and what it
does (and how compatible the hardware behind it is) remains important. I wish
it wasn't, but people designing without that realisation will be doing their
sales pitch to a smaller audience. 

I apologise for taking such a long time to say this, and for inserting apologies
every other sentence for defending antiquated PC technology, but there are some
important plusses there, and the temptation to reject it completely is rather
fool-hardy, in my humble opinion. 

Bye for now,
Mark Aitchison, Physics, University of CAnterbury, New Zealand.

peter@ficc.ferranti.com (Peter da Silva) (11/06/90)

In article <1990Nov6.101902.9683@canterbury.ac.nz> phys169@canterbury.ac.nz writes:
> now, there are becoming less and less buyers that actually need
> that extra technology (although everyone will say it's nice). The "bread and
> butter" for computer manufacturers will remanin with the majority of users in
> offices and the like, where something like a PC is good enough.

I've got news for you... this has been the case since 1980 at least. Most
users of IBM-PCs would be perfectly well served by a 64K Z-80-based machine
running CP/M. The "gee whiz" technology really does sell machines.

> All this, of course, has a motive behind it; I've been wanting to buy some
> workstations which will run X-windows, with good speed, and yet not loose
> anything we had with 286-based PC's.

I personally can't think of anything off the top of my head that a 286
based PC offers that I want. What are you talking about here? For running
MS-DOS software, an 8088 based PC is fine. For anything else, a 68000
based PC is much better.
-- 
Peter da Silva.   `-_-'
+1 713 274 5180.   'U`
peter@ferranti.com

guy@auspex.auspex.com (Guy Harris) (11/07/90)

>The two parts of this sentence are unrelated. :-)  I haven't seen details
>on the SLC, but Sun normally uses proprietary MMU designs that bear no
>relation to (e.g.) the "Sparc Reference MMU".

I've read stuff that leads me to believe that LSI Logic has, in addition
to their SPARC+reference MMU chip set, a chip set that includes a Sun
MMU (perhaps the one they sell to Sun for the various Desktop SPARC
machines).

graeme@labtam.labtam.oz (Graeme Gill) (11/07/90)

In article <1990Nov6.101902.9683@canterbury.ac.nz>, phys169@canterbury.ac.nz writes:
> 
> Not that I, for one, think I have enough computer power at
> the moment, but as more people start to realise they would be paying more for
> power they don't need, they will be content to stick with (say) Asian
> manufacturers turning out acceptable-performance machines using yesterday's
> technology. This seems to be the real limit of growth, not bus bandwidth or
> the speed of light.  
> 

	There seems to be a definite 'knee'
in the performance/usability curve of an X server. Measured by the Xstone
benchmark (and the sort of applications currently available) that knee occurs
somewhere around 20K to 25K Xstones. PC based X terminal emulators have
a performance around the 2 - 5K xstones, well short of the mark. What
I am saying is that there is still a lot of room for performance
improvements in PC products. I also have information that suggests
that a number of asian manufacturers are seriously looking at mass
manufacture of cheap fast X terminals.

> 
> So, if you can't make a good Xterminal out of a PC by adding software, how
> about a replacement graphics card with Ethernet & 2nd CPU on-board?  That
> would solve bandwidth problems and compatibility problems (given the right
> hardware design).
> 
> Mark Aitchison, Physics, University of CAnterbury, New Zealand.

	An excellent idea that would provide a standard graphics interface for 
all software running on a PC type platform, even MS-DOS programs. Unfortunately
for it to work there would have to be wide acceptance of the interface standard
within the PC community, and I suspect that the window of opportunity for
this product is nearly closed. It would need:

1) A massed produced X interface card ie:
	80960/29000/34020 + 82596 + 2/4Meg RAM + Vram + ASIC + BT459/ecl
	shift register on a card for < $1000

2) Software support from some notable operating systems and applications
   developers - ie Microsoft, Autocad, Lotus etc.

3) Inclusion as standard from some notable manufacturer, ie IBM, Compaq etc.

	To my mind a graphics card with X as the interface makes much more
sense than the current mish mash of low performance products and standards -
e.g. VGA, TMS340XX standard, 8515A etc.  Since the X server would most
likely be uploaded, there would also be scope for keeping up with
changes in graphics standards, and the splitting of the workload
would lead to better performance. - and another thing, the PC applications
would then become X11 compatible; at last you could run all those nifty
PC programs from your Xterminal/Workstation etc.

	Graeme Gill
	Electronic Design Engineer
	Labtam I.S.D. Pty Ltd

davidsen@crdos1.crd.ge.COM (Wm E Davidsen Jr) (11/07/90)

In article <2PX6KJ@xds13.ferranti.com> peter@ficc.ferranti.com (Peter da Silva) writes:

| I personally can't think of anything off the top of my head that a 286
| based PC offers that I want. What are you talking about here? For running
| MS-DOS software, an 8088 based PC is fine. For anything else, a 68000
| based PC is much better.

  If you want UNIX+DOS capability the 80486 seems most cost effective.
If you want just UNIX, or must have BSD, you are probably better off
with a RISC machine. Until the 68040 is available the 68k family seems
to be slightly down on performance relative to the 486 and RISC
machines.
-- 
bill davidsen	(davidsen@crdos1.crd.GE.COM -or- uunet!crdgw1!crdos1!davidsen)
      The Twin Peaks Halloween costume: stark naked in a body bag

henry@zoo.toronto.edu (Henry Spencer) (11/08/90)

In article <3698@skye.ed.ac.uk> richard@aiai.UUCP (Richard Tobin) writes:
>>Both [PC compatibility and X] do terrible things to your system design if you
>>enshrine them as fundamental goals...
>
>I would be interested to hear you elaborate on this - in particular,
>what does "enshrining X as a fundamental goal" involve other than
>having "a sane machine with a clean frame buffer".

The problem with fundamental PC compatibility is obvious:  it dooms you to
using a grossly obsolete CPU architecture.  The problem with X is more
subtle:  it's so huge and slow that you end up struggling desperately to
provide more and more computational resources just so X will run tolerably,
at the expense of rather greater cost and complexity than would be needed
in a just world.

I may perhaps have been a little harsh on X in that comment.  A little.
-- 
"I don't *want* to be normal!"         | Henry Spencer at U of Toronto Zoology
"Not to worry."                        |  henry@zoo.toronto.edu   utzoo!henry

keith@mips.COM (Keith Garrett) (11/08/90)

In article <2PX6KJ@xds13.ferranti.com> peter@ficc.ferranti.com (Peter da Silva) writes:
[...]
>I personally can't think of anything off the top of my head that a 286
>based PC offers that I want. What are you talking about here? For running
>MS-DOS software, an 8088 based PC is fine. For anything else, a 68000
>based PC is much better.
if you check the requirements for the latest versions of many DOS applications,
they now require 286 compatibility.
-- 
Keith Garrett        "This is *MY* opinion, OBVIOUSLY"
      Mips Computer Systems, 930 Arques Ave, Sunnyvale, Ca. 94086
      (408) 524-8110     keith@mips.com  or  {ames,decwrl,prls}!mips!keith

sysmgr@KING.ENG.UMD.EDU (Doug Mohney) (11/09/90)

In article <42906@mips.mips.COM>, keith@mips.COM (Keith Garrett) writes:

>if you check the requirements for the latest versions of many DOS applications,
>they now require 286 compatibility.

Homie don't think so! 

Anything which runs on a 80286 can (97.5% of the time) run on a 8088, abet
slower. My roomie in particular grumbles about the slowness of MechWarrior
on his paltry IBM Portable (yes, when IBM tried to clone the Compaq sewing
machine..), and often covets my machine ('286) for an increase.

Of course, the '286 gives you extended/expanded (pick one, I don't keep track
of the difference), but if you need something THAT high powered, you should (in
my humble opinion) proceed directly to Mr. '386 DX @ 20Mhz. (Yes, I s'pose
you could use the '386 SX, but somehow my knee jerks at a chip which was
basically designed to kick the '286 clones into the dustbin, thereby
maintaining Intel's monopoly upon that market).

staff@cadlab.sublink.ORG (Alex Martelli) (11/09/90)

graeme@labtam.labtam.oz (Graeme Gill) writes:
	...
>would lead to better performance. - and another thing, the PC applications
>would then become X11 compatible; at last you could run all those nifty
>PC programs from your Xterminal/Workstation etc.

According to Quarterdeck advertising (a neat brochure in a recent issue
of BYTE mag), this compatibility can be yours next January with
X/Desqview.  A SW-only solution, so performance is in question, but...

-- 
Alex Martelli - CAD.LAB s.p.a., v. Stalingrado 45, Bologna, Italia
Email: (work:) staff@cadlab.sublink.org, (home:) alex@am.sublink.org
Phone: (work:) ++39 (51) 371099, (home:) ++39 (51) 250434; 
Fax: ++39 (51) 366964 (work only), Fidonet: 332/401.3 (home only).

kls30@duts.ccc.amdahl.com (Kent L Shephard) (11/09/90)

-STUFF DELETED-
>> All this, of course, has a motive behind it; I've been wanting to buy some
>> workstations which will run X-windows, with good speed, and yet not loose
>> anything we had with 286-based PC's.
>
>I personally can't think of anything off the top of my head that a 286
>based PC offers that I want. What are you talking about here? For running
>MS-DOS software, an 8088 based PC is fine. For anything else, a 68000
>based PC is much better.
That's why more Intel based (286 & 386) machines run UNIX than any other.
68000 may be comprable but not better INMO.  Not wanting a flame war but
just wanted the facts straight.

>-- 
>Peter da Silva.   `-_-'
>+1 713 274 5180.   'U`
>peter@ferranti.com
                              Kent.

--
/*  -The opinions expressed are my own, not my employers.    */
/*      For I can only express my own opinions.              */
/*                                                           */
/*   Kent L. Shephard  : email - kls30@DUTS.ccc.amdahl.com   */

phys169@canterbury.ac.nz (11/12/90)

In article <0093F67E.F8E473A0@KING.ENG.UMD.EDU>, sysmgr@KING.ENG.UMD.EDU (Doug Mohney) writes:

> Anything which runs on a 80286 can (97.5% of the time) run on a 8088, albeit
> slower. 

Some new software (like big speedsheets and DTP-type stuff) needs a 286 or
better. But the main thing is having 16-bit slots for some cards. Any software
that runs well enough on an 8088 is old and/or trivial! ;-)

Mark Aitchison.

brett@cayman.amd.com (Brett Stewart) (11/13/90)

In article <0093F295.10626840@KING.ENG.UMD.EDU>
    sysmgr@KING.ENG.UMD.EDU (Doug Mohney) writes:
>In article <1990Nov3.052952.1786@zoo.toronto.edu>,
    henry@zoo.toronto.edu (Henry Spencer) writes:
>>In article <0093F1A8.A28E4920@KING.ENG.UMD.EDU>
    sysmgr@KING.ENG.UMD.EDU (Doug Mohney) writes:
>>>...use RISC processor and stick in Soft-PC in ROMs...

Some makers of 29K-based X terminals are considering doing something
similar to this.  The idea is Xterm/PC/3270 based on a software
switch.  Only one neat, quiet box on the desktop.

>>
>>A small practical difficulty with this approach is that Soft PC is licensed
>>software.  It also does a less than wonderful job of emulation, as our
>>department is finding out on a bunch of DEC RISC workstations for undergrad
>>teaching...

I had the good fortune to host a COMPCON session a few years ago ('89)
that was quite well attended.  The subject was execution of a guest
architecture on a host.  There were to be three papers:

   Luther Johnson, then of Phoenix Technology, on Phoenix's
   MIMIC-derived version od DOS on 'other'

   John Banning, then (and possibly now - are you still there John?)
   of Hunter Systems, on Hunter's compile-the-binaries strategy of
   DOS on Unix, and

   Insignia Solutions on SoftPC strategy.  Unfortunately, Insignia
   was a no-show to the session, so I did not get to learn more than
   is in the published papers.

My understanding is that the Insignia guys are switching over to the
Phoenix method, and licensing some of Phoenix' technology.

As for pricing, I dont know about SoftPC at retail, but the OEM
pricing I have heard shouldn't make anyone blink.

Interested persons can see about this technology by referring to the
paper, by Cathy May, 'MIMIC: A fast System 370 simulator' or
something like that, in the proceedings of an '87 SIGPLAN symposium on
interpretation.  This paper is more a starting point than a
comprehensive how-to paper.

Many customers of our AMD 29K are interested in preserving old binaries
of CISC machines by using a pure-software, or hardware-assisted
technique to allow them to execute on the 29K.  I believe the
preference for the 29K architecture for this (and hence the
relevance of this posting) is due to the ability of the 29K to store
a model of the 'volatile state' of the guest architecture in its
capacious register file and still have enough room left over to run
the MIMIC-type part of the interpretative system.

On the subject of architecture neutrality, did anybody visit the
OSF's demonstratiomn of 4 different Architecture-Neutral-Distribution-
Format (ANDF) technology last week?
Best Regards; Brett Stewart
Advanced Micro Devices, Inc.           1-512-462-5321  FAX
5900 E. Ben White Blvd MS561           1-512-462-4336  Telephone
Austin, Texas 78741      USA           brett@cayman.amd.com