cs472119@umbc5.umbc.edu (cs472119) (11/29/90)
I know this has been discussed before, and recently, but I paid no attention since I thought my chances of getting an A3000 were nil. I sincerely apologize! Will the A3000/16 with a 25 mhz 68040 card perform exactly the same as an A3000/25 with the same 25 mhz 68040 card? I seem to remember someone saying that as long as the memory chips in the A3000/16 were as fast as those in the A3000/25 (and they are), the bus speed was changable, or words to that effect. True or False? Thanks! Larry
hclausen@adspdk.UUCP (Henrik Clausen) (12/03/90)
In article <4551@umbc3.UMBC.EDU>, cs472119 writes: > Will the A3000/16 with a 25 mhz 68040 card perform exactly the same as > an A3000/25 with the same 25 mhz 68040 card? I seem to remember someone > saying that as long as the memory chips in the A3000/16 were as fast > as those in the A3000/25 (and they are), the bus speed was changable, or > words to that effect. True or False? True :-) The ZorroIII bus is not tied to the CPU speed. So getting a 16 MHz is a good deal if you anticipate moving on to the 68040 next year. -Henrik | Henrik Clausen, Graffiti Data | If the Doors of Perception where cleansed, | | ...{pyramid|rutgers}!cbmvax! | Man would see Reality as it is - Infinite. | \______cbmehq!adspdk!hclausen___|_________________________________W. Blake___/
limonce@pilot.njin.net (Tom Limoncelli) (12/05/90)
In article <184e255a.ARN04328@adspdk.UUCP> hclausen@adspdk.UUCP (Henrik Clausen) writes: > In article <4551@umbc3.UMBC.EDU>, cs472119 writes: > >[ If I plan on getting an '040 card for my Amiga 3000 is it better > > to have a /16 or a /25?] > So getting a 16 MHz is a good deal if you anticipate moving on to the > 68040 next year. Now I've heard that question answered both ways. The person that opposed the above answer was one of the designers of the Amiga 3000. Basically, the Zorro III bus is effected by the speed of the system so the faster you get your Amiga 3000, the faster the '040 will be at certain operations. -Tom -- tlimonce@drew.edu Tom Limoncelli "Flash! Flash! I love you! tlimonce@drew.bitnet +1 201 408 5389 ...but we only have fourteen tlimonce@drew.uucp limonce@pilot.njin.net hours to save the earth!"
daveh@cbmvax.commodore.com (Dave Haynie) (12/06/90)
In article <Dec.5.01.22.13.1990.10247@pilot.njin.net> limonce@pilot.njin.net (Tom Limoncelli) writes: >In article <184e255a.ARN04328@adspdk.UUCP> hclausen@adspdk.UUCP (Henrik Clausen) writes: >> In article <4551@umbc3.UMBC.EDU>, cs472119 writes: >> >[ If I plan on getting an '040 card for my Amiga 3000 is it better >> > to have a /16 or a /25?] >Now I've heard that question answered both ways. The person that >opposed the above answer was one of the designers of the Amiga 3000. >Basically, the Zorro III bus is effected by the speed of the system so >the faster you get your Amiga 3000, the faster the '040 will be at >certain operations. Ok, lemme settle this. First of all, we're confusing the issue here a little. The speed of a Zorro III bus transaction is determined, within some reasonable physical limits, only by the speed of the bus master and slave involved in that transaction. When the A3000 motherboard is acting as Zorro III bus master, the A3000 motherboard's system clock determines the speed of the transaction, because of the way I happened to design that bus controller. Any bus master you put into the Zorro III bus will run that bus at its speed, not at the A3000 motherboard speed. None of which immediately concerns anyone anyway, since 68040 cards don't likely sit on the Zorro III bus, but instead in the Coprocessor slot. Now, the Coprocessor slot is set up to be very flexible, and allow a card to be designed to act either synchronous to the A3000 bus clock or asynchronous to the A3000 system. Since the 68030/(68881|2) in the system are the only parts that are different between an A3000/16 and an A3000/25, we made it possible for a Coprocessor card to drive the A3000 system bus clocks on its own, leaving the on-board processor driven by its on-board clocks. So a Coprocessor card can run a 16MHz system's motherboard at 25MHz. The on-board 68030 will of course still only work at 16MHz, so it must be shut off in any such setup. With a 25MHz A3000, you might have both Coprocessor board and on-board 68030 running at the same time at 25MHz. That's the only thing you can't do on a 16MHz system than you can on a 25MHz system. >tlimonce@drew.edu Tom Limoncelli "Flash! Flash! I love you! -- Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests" {uunet|pyramid|rutgers}!cbmvax!daveh PLINK: hazy BIX: hazy Wheeeeeeeeeeeeeeee...........
hclausen@adspdk.UUCP (Henrik Clausen) (12/06/90)
In article <Dec.5.01.22.13.1990.10247@pilot.njin.net>, Tom Limoncelli writes: > Now I've heard that question answered both ways. The person that > opposed the above answer was one of the designers of the Amiga 3000. > Basically, the Zorro III bus is effected by the speed of the system so > the faster you get your Amiga 3000, the faster the '040 will be at > certain operations. In that case, I bow low and stand corrected :-) -Henrik | Henrik Clausen, Graffiti Data | If the Doors of Perception where cleansed, | | ...{pyramid|rutgers}!cbmvax! | Man would see Reality as it is - Infinite. | \______cbmehq!adspdk!hclausen___|_________________________________W. Blake___/
rblewitt@sdcc6.ucsd.edu (Richard Blewitt) (12/07/90)
In article <16318@cbmvax.commodore.com> daveh@cbmvax.commodore.com (Dave Haynie) writes: >run a 16MHz system's motherboard at 25MHz. The on-board 68030 will of course >still only work at 16MHz, so it must be shut off in any such setup. With a >25MHz A3000, you might have both Coprocessor board and on-board 68030 running >at the same time at 25MHz. That's the only thing you can't do on a 16MHz >system than you can on a 25MHz system. So it IS possible to have them both running at the same time!! So what are your plans for this great setup? Come on Dave, throw us a bone :) Rick Blewitt rblewitt@ucsd.edu
david@twg.com (David S. Herron) (12/12/90)
In article <16318@cbmvax.commodore.com> daveh@cbmvax.commodore.com (Dave Haynie) writes: >In article <Dec.5.01.22.13.1990.10247@pilot.njin.net> limonce@pilot.njin.net (Tom Limoncelli) writes: >>In article <184e255a.ARN04328@adspdk.UUCP> hclausen@adspdk.UUCP (Henrik Clausen) writes: > > With a >25MHz A3000, you might have both Coprocessor board and on-board 68030 running >at the same time at 25MHz. That's the only thing you can't do on a 16MHz >system than you can on a 25MHz system. ... > Wheeeeeeeeeeeeeeee........... I couldn't have said it better .. ;-) Now for some software to spawn "tasks" into the "other" processor ... (doesn't sound very easy.. but would be a great addition.. and, of course, it would be better if AmigaDOS were to become multi-processor capable.. but, of course, that's not very easy..) -- <- David Herron, an MMDF & WIN/MHS guy, <david@twg.com> <- Formerly: David Herron -- NonResident E-Mail Hack <david@ms.uky.edu> <- <- "bnews must die" -- From: Rick Adams <rick@uunet.uu.net>