pcg@cs.aber.ac.uk (Piercarlo Grandi) (11/05/90)
Henry Spencer observed:
henry> ... Sun normally uses proprietary MMU designs that bear no
henry> relation to (e.g.) the "Sparc Reference MMU". Worse, not only
henry> are they proprietary but they are Top Secret, although apparently
henry> Sun has entirely forgotten why, since they can't offer any
henry> rational reason for it when asked.
Uhm? I have copy of an article in the SUN magazine that gives virtually
all the necessary details. A quick look at /usr/include/sun*/mmu.h will
tell you all necessary details.
Maybe not for the MMU, but SUN is famous for witholding other useful
engineering details, and even MMU information has to be deduced, rather
than read plainly in some document.
On 3 Nov 90 23:59:58 GMT, henry@zoo.toronto.edu (Henry Spencer) said:
henry> In article <1990Nov3.150202.27353@ameristar> rick@ameristar (Rick
henry> Spanbauer) writes:
rick> It may be a simple reason, like not wanting users to be able to
rick> buy only SunOS tapes from Sun and then run the binaries on cheap
rick> sparc clones, or to make the job of clone companies harder...
Actually you *can* do that; people can license SunOS and offer it on
their platforms. Also, people can provide a SunOS compatible ABI.
Another simple reason may be to prevent people from implementing non
SunOS operating systems on their hardware. But indeed if you try hard
enough you can do it, as correctly observed:
henry> I said "rational reason". The problem with the idea of keeping
henry> it secret from the competition is that it's not that hard to
henry> reverse-engineer the stuff if you try. [ ... ] This policy makes
henry> life harder only for the legitimate customers.
Another irrational reason, and one that is actually behind many
corporate secrets (and military ones) is shame for a badly done job. In
particular SUN MMUs have always been designed in a regrettable (when not
outright unbelievable) way.
--
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.ukrick@ameristar (Rick Spanbauer) (11/05/90)
In article <PCG.90Nov4181554@athene.cs.aber.ac.uk> pcg@cs.aber.ac.uk (Piercarlo Grandi) writes: >henry> In article <1990Nov3.150202.27353@ameristar> rick@ameristar (Rick >henry> Spanbauer) writes: > >rick> It may be a simple reason, like not wanting users to be able to >rick> buy only SunOS tapes from Sun and then run the binaries on cheap >rick> sparc clones, or to make the job of clone companies harder... > >Actually you *can* do that; people can license SunOS and offer it on >their platforms. Also, people can provide a SunOS compatible ABI. > >Another simple reason may be to prevent people from implementing non >SunOS operating systems on their hardware. But indeed if you try hard >enough you can do it, as correctly observed: No, I think you both missed my point (which perhaps says I should have made it better :-) ) - without the prprietery MMU, the clone folks could get SunOS the way PC types get MS-DOS, ie no license fee. Just tell their customers to buy tapes from Sun and load them up. Thus Sun looses both the hardware sale and the large front licensing fee they would normally collect. >Piercarlo "Peter" Grandi | ARPA: pcg%uk.ac.aber.cs@nsfnet-relay.ac.uk Rick Spanbauer Ameristar
henry@zoo.toronto.edu (Henry Spencer) (11/06/90)
In article <1990Nov5.122811.310@ameristar> rick@ameristar (Rick Spanbauer) writes: > ... without the prprietery MMU, the clone > folks could get SunOS the way PC types get MS-DOS, ie no license > fee. Just tell their customers to buy tapes from Sun and load > them up. Thus Sun looses both the hardware sale and the large > front licensing fee they would normally collect. Uh, you can't buy tapes from Sun without the license, so they can still gouge you for licensing fees. As for hardware, Sun has been heard to loftily proclaim "we're a software company now". (Yeah, sure.) -- "I don't *want* to be normal!" | Henry Spencer at U of Toronto Zoology "Not to worry." | henry@zoo.toronto.edu utzoo!henry
mslater@cup.portal.com (Michael Z Slater) (11/07/90)
Sun's MMU design is no longer proprietary. Sun has licensed LSI logic to sell the chip set from the SPARCstation 1, which includes the Sun MMU. The chip set sells for $999 in thousands, including the integer unit but not the FPU (which is another $150). This price includes the right to distribute the SunOS binary with each machine. Michael Slater, Microprocessor Report mslater@cup.portal.com