dgc@euphemia.math.ucla.edu (David G. Cantor) (10/01/90)
Could one use the old 68030 board in a cube, along with the new 68040
board, by
1. Cutting its traces to the internal scsi bus,
2. Connecting its ethernet port to the 68040 board ethernet port with
a piece of coax, and
3. Treating it as a diskless workstation, booting off of the 68040
board, which is connected to its own internal hard disk, etc.
You would gain two serial-ports, a dsp port, a scsi-1 bus interface
(to the external world), a second printer-port and a second dsp port,
plus a second, slower computer.
The main cost, it if would work, would be the ram. But 16 sims would
probably only cost $800.00 and you get quite a lot for that cost.
The clear reason for putting the 68030 board back in the cube is that
the cube has the right power supply, space, and backplane.
dgc
David G. Cantor
Department of Mathematics
University of California at Los Angeles
Internet: dgc@math.ucla.eduizumi@fugitive.berkeley.edu (Izumi Ohzawa) (10/01/90)
In article <448@kaos.MATH.UCLA.EDU> dgc@euphemia.math.ucla.edu (David G. Cantor) writes: >Could one use the old 68030 board in a cube, along with the new 68040 >board, by [stuff deleted ..] >The main cost, it if would work, would be the ram. But 16 sims would >probably only cost $800.00 and you get quite a lot for that cost. What does NeXT charge for upgrade if we do not return the 68030 board? In other words, what's the trade-in value for the old CPU board? Have you actually done this? Izumi Ohzawa, izumi@violet.berkeley.edu
daugher@cs.tamu.edu (Dr. Walter C. Daugherity) (10/02/90)
In article <448@kaos.MATH.UCLA.EDU> dgc@euphemia.math.ucla.edu (David G. Cantor) writes: >Could one use the old 68030 board in a cube, along with the new 68040 >board, by >1. Cutting its traces to the internal scsi bus, Except for power :-). [lines deleted about hooking the ethernet ports together to make the 68030 a diskless NeXT] Actually this is a brilliant idea, but why stop at one 68030 and one 68040? Why not have THREE 68030's and one 68040?!!! There is one "minor" detail to be resolved: will NeXT require the 68030 board (minus RAM) to be returned to get the 68040 RAM-less board for $1300 list plus $195 list for Software Release 2.0 Extended? (You keep your RAM to put in the new board.) I was led to believe that you would have to "trade in" your old board, but I have just reread both the May 9 press release and the new "Fall 1990 List Prices" booklet, AND NEITHER ONE MENTIONS RETURNING THE 68030 BOARD!!! In a previous posting I suggested NeXT could make a lot of friends and get a lot of positive exposure by repackaging returned 68030 boards into a single- board enclosure a la NeXTstation and selling them VERY cheap to universities. Once they've actually used a NeXT, they'll be eager to buy 68040 NeXT's. This would be a dandy way to buy market share in the bulk of universities which haven't received any penetration from NeXT. This would benefit NeXT much more than desoldering the old boards to salvage the chips. Now I think maybe I can keep the 68030 board after all, buy another B&W display ($995 list) and keyboard and mouse ($225 list) and some RAM, and make a great two-fer (ya know, one fer you and one fer me--if you haven't heard the NeXT country and western song, it's a scream). Just as long as your desk is no more than three feet away (unless you want to design your own display cable repeater :-)). As always, educational discounts apply. ------------------------------------------------------------------------------- Walter C. Daugherity Internet, NeXTmail: daugher@cs.tamu.edu Knowledge Systems Research Center uucp: uunet!cs.tamu.edu!daugher Texas A & M University BITNET: DAUGHER@TAMVENUS College Station, TX 77843-3112 CSNET: daugher%cs.tamu.edu@RELAY.CS.NET ---Not an official document of Texas A&M---
bb@shark.cis.ufl.edu (Brian Bartholomew) (10/03/90)
Hey, using your old board is a fantastic idea. However, from the hardware perspective, someone needs to sit down a do a little arithmetic about power requirements and heat disapation, before lots of people slowly cook thier machines from too much heat and brownouts. I expect that there will soon be a hopping market on '030 motherboards; and I might lead the pack 1/2 :-) "Any sufficiently advanced technology is indistinguishable from a rigged demo." ------------------------------------------------------------------------------- Brian Bartholomew UUCP: ...gatech!uflorida!beach.cis.ufl.edu!bb University of Florida Internet: bb@beach.cis.ufl.edu -- "Any sufficiently advanced technology is indistinguishable from a rigged demo." ------------------------------------------------------------------------------- Brian Bartholomew UUCP: ...gatech!uflorida!beach.cis.ufl.edu!bb University of Florida Internet: bb@beach.cis.ufl.edu
mdixon@parc.xerox.com (Mike Dixon) (10/03/90)
this was discussed many months ago, and as i remember the consensus
was that the cube power supply would only support one of the main
NeXT boards (since they draw a lot of power for the display). the
remaining slots only supply enough power for processor-only boards.
--
.mike.glenn@heaven.woodside.ca.us (Glenn Reid) (10/03/90)
In article <MDIXON.90Oct2190616@thelonius.parc.xerox.com> mdixon@parc.xerox.com (Mike Dixon) writes: >this was discussed many months ago, and as i remember the consensus >was that the cube power supply would only support one of the main >NeXT boards (since they draw a lot of power for the display). the >remaining slots only supply enough power for processor-only boards. A NeXT service technician told me, in an informal setting that doesn't make it gospel, that the cube has ample power and ventilation for four circuit boards. After all, it was designed with that many slots. I also think that the Ariel multi-processor boards would pose the same problem if it were a real problem. In short, I think that power and ventilation aren't the problem. The problem is more likely to be that NeXT wants the boards as trade-ins. Just my own $.02. Glenn -- Glenn Reid RightBrain Software glenn@heaven.woodside.ca.us PostScript/NeXT developers ..{adobe,next}!heaven!glenn 415-851-1785
smb@datran2.uunet (Steven M. Boker) (10/03/90)
In article <MDIXON.90Oct2190616@thelonius.parc.xerox.com>, mdixon@parc.xerox.com (Mike Dixon) writes: > this was discussed many months ago, and as i remember the consensus > was that the cube power supply would only support one of the main > NeXT boards (since they draw a lot of power for the display). the > remaining slots only supply enough power for processor-only boards. My understanding is that the main boards can be useda as long as secondary monitors are not used. NeXT was worried that people would try to plug in the second monitor and that would start a fish N chip fry. My understanding is that it was not difficult to set Mach up so that the other boards were recognized as network devices, however this might take kernel source. Something outsiders do not seem to be trusted with. Steve. -- #====#====#====#====#====#====#====#====#====#====#====#====#====#====#====# # Steve Boker # Black holes are how God divides by zero. # # smb@datran2.uunet.uu.net # ....I have my own methods. # #====#====#====#====#====#====#====#====#====#====#====#====#====#====#====#
rca@cs.brown.edu (Ronald C.F. Antony) (10/11/90)
In article <287@heaven.woodside.ca.us> glenn@heaven.woodside.ca.us (Glenn Reid) writes: >In short, I think that power and ventilation aren't the problem. >The problem is more likely to be that NeXT wants the boards as >trade-ins. The problem is not having two boards in one system, but running two monochrome megapixel displays from two boards. Thus the system has to supply two times the high currency for the display. If you have just two processor boards and only one monochrome megapixel display, then there shouldn't be a problem from power supply. Of course you would need the bus chip and most probably some MACH modifications or device drivers. But I guess these things are best answered by some NeXT people. Ronald ------------------------------------------------------------------------------ "The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man." Bernhard Shaw | rca@cs.brown.edu or antony@browncog.bitnet
cnh5730@calvin.tamu.edu (Chuck Herrick) (10/11/90)
In article <52796@brunix.UUCP> rca@cs.brown.edu (Ronald C.F. Antony) writes: )In article <287@heaven.woodside.ca.us> glenn@heaven.woodside.ca.us (Glenn Reid) writes: ))In short, I think that power and ventilation aren't the problem. ))The problem is more likely to be that NeXT wants the boards as ))trade-ins. ) )The problem is not having two boards in one system, but running two )monochrome megapixel displays from two boards. Thus the system has to )supply two times the high currency for the display. Actually, the source with the greatest potential for problems in a multiple-processor-boarded cube would be likely to arise from the following: Which board is in control of the bus and when? Several backplane/bus configurations have been designed from the start to handle more than one processor board (VME, Futurebus 1 and 2, and STD come to mind). A set of bus-master/bus-slave protocols are designed into these buses from the very beginning, and these protocols, when followed, prevent interboard interference. Hope this helps. -- Chuck Herrick cnh5730@calvin.tamu.edu
paul@taniwha.UUCP (Paul Campbell) (10/18/90)
In article <8986@helios.TAMU.EDU> cnh5730@calvin.tamu.edu (Chuck Herrick) writes: >Actually, the source with the greatest potential for problems in a >multiple-processor-boarded cube would be likely to arise from the >following: > Which board is in control of the bus and when? >Several backplane/bus configurations have been designed from the >start to handle more than one processor board (VME, Futurebus 1 and 2, >and STD come to mind). A set of bus-master/bus-slave protocols are >designed into these buses from the very beginning, and these >protocols, when followed, prevent interboard interference. NuBus (and NextBus) both support multiple masters and correctly arbitrate between them (assuming everyone is playing by the rules), however bus arbitration times take two bus clocks (200nS on NuBus, 160nS on NextBus), with one CPU board in the system your CPU board is 'parked' on the bus (which means that each bus cycle can skip the arbitration times). With two bus masters in the system boards will tend to find themselves parked on the bus about half the time giving a 1 clock average penalty for bus transfers (80nS), with 3 processors it becomes 4/3 clocks average (107nS) etc Of course this assumes that bus cycles don't collide (ie one processor isn't waiting for the other), in this case the arbitration times are hidden behind the current transfer. I think that the net effect of this will be to slow the system down a lot when you put on two boards, things will continue at this rate until the bus becomes saturated at this point things will slow down at a slower rate. Of course none of this takes into account software, if you are only using the NuBus to talk to a framestore, and the software makes sure that no more one process is talking to it at anyone time then there's no problem. On the other hand if your CPUs are sharing their main memorys then on average every other cycle will have to go over the NuBus to access the other CPU's memory (if you put kernels on both of them its probably going to be more between 1 of 4 and 1 of 2), each time you access the other CPU's memory you stop it from accessing it (and your's too). This will cause saturation to occur much faster (in fact in this case using seperate NuBus RAM would really help). Paul Campbell -- 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 ..... :-)