mike@ccd700.UUCP (M. Greer) (10/25/90)
Will a 25 mhz 68020 work on an A2620? This seems like such a simple question, but I can't seem to get a reliable answer. I called two different dealers, who in turn called Commodore tech support, and I have recieved two different answers. One said it would work but could not qurantee that it would clock at 25 mhz (assuming of course that a 25 mhz clock crystal and a 25 mhz 68881 or 82 were also added), the other said that it would work and run at 25 mhz. Who is right? This is the most economical way for me to accellerate my machine and I need accurate information. Our node here has a small disk, there I don't get all of the posted messages. If in response to this post, you could also e-mail or even call me at (313)845-4070 I would greatly appreciate it. Mike Greer
joseph@valnet.UUCP (Joseph P. Hillenburg) (10/29/90)
mike@ccd700.UUCP (M. Greer) writes: > Will a 25 mhz 68020 work on an A2620? This seems like such a simple > question, but I can't seem to get a reliable answer. I called two > different dealers, who in turn called Commodore tech support, and I > have recieved two different answers. One said it would work but could > not qurantee that it would clock at 25 mhz (assuming of course that > a 25 mhz clock crystal and a 25 mhz 68881 or 82 were also added), the > other said that it would work and run at 25 mhz. Who is right? This is > the most economical way for me to accellerate my machine and I need > accurate information. Our node here has a small disk, there I don't > get all of the posted messages. If in response to this post, you could > also e-mail or even call me at (313)845-4070 I would greatly appreciate > it. > > Mike Greer Yes. From what I heard from both Commodore and AmigaWhirl/World (FluffMag) you can speed up the board just by adding the new chip(s) and the oscillator. -Joseph Hillenburg UUCP: ...iuvax!valnet!joseph ARPA: valnet!joseph@iuvax.cs.indiana.edu INET: joseph@valnet.UUCP
peterk@cbmger.UUCP (Peter Kittel GERMANY) (10/30/90)
In article <0eqRR4w163w@valnet> joseph@valnet.UUCP (Joseph P. Hillenburg) writes: >mike@ccd700.UUCP (M. Greer) writes: > >> Will a 25 mhz 68020 work on an A2620? This seems like such a simple > >Yes. From what I heard from both Commodore and AmigaWhirl/World >(FluffMag) you can speed up the board just by adding the new chip(s) and >the oscillator. I think here were some things mixed up. 1) You CAN speed up the 68881/2 by just putting in an own, faster oscillator for it and changing one jumper. 2) Changing the processor clock is not officially supported. Dave Haynie answered this already and did not recommend it. He says there are too many risks that the system may fail in at least some situations. -- Best regards, Dr. Peter Kittel // E-Mail to \\ Only my personal opinions... Commodore Frankfurt, Germany \X/ {uunet|pyramid|rutgers}!cbmvax!cbmger!peterk
billsey@agora.uucp (Bill Seymour) (10/31/90)
In article <858@ccd700.UUCP> mike@ccd700.UUCP (M. Greer) writes:
:Will a 25 mhz 68020 work on an A2620? This seems like such a simple
:question, but I can't seem to get a reliable answer. I called two
:different dealers, who in turn called Commodore tech support, and I
:have recieved two different answers. One said it would work but could
:not qurantee that it would clock at 25 mhz (assuming of course that
:a 25 mhz clock crystal and a 25 mhz 68881 or 82 were also added), the
:other said that it would work and run at 25 mhz. Who is right? This is
:the most economical way for me to accellerate my machine and I need
:accurate information. Our node here has a small disk, there I don't
:get all of the posted messages. If in response to this post, you could
:also e-mail or even call me at (313)845-4070 I would greatly appreciate
:it.
:
:Mike Greer
You could plug a 25MHz part in, but since the board is designed
as 14.32MHz syncronous, you wouldn't see any speed increase. You would
still be clocking the 68020 at the same speed as before. Changing to
a different speed crystal would just cause the syncronous design to try
anbd go async, which wouldn't work. I'm afraid to say that if you want
25MHz, you're better off to buy a 2630 or 3000.
--
-Bill Seymour billsey@agora
***** American People/Link Amiga Zone Hardware Specialist NES*BILL *****
Bejed, Inc. NES, Inc. Northwest Amiga Group At Home Sometimes
(503) 281-8153 (503) 246-9311 (503) 656-7393 BBS (503) 640-0842daveh@cbmvax.commodore.com (Dave Haynie) (11/01/90)
In article <0eqRR4w163w@valnet> joseph@valnet.UUCP (Joseph P. Hillenburg) writes: >mike@ccd700.UUCP (M. Greer) writes: > >> Will a 25 mhz 68020 work on an A2620? Well, an MC68020-25 will WORK in the A2620, but there's no way to clock it at 25MHz, which is no doubt what you're after. >>This seems like such a simple question, but I can't seem to get a reliable >>answer. You have it here on good authority; I designed the thing. >>not qurantee that it would clock at 25 mhz (assuming of course that >>a 25 mhz clock crystal and a 25 mhz 68881 or 82 were also added), the >>other said that it would work and run at 25 mhz. The 68881/2 can certainly run at 25MHz (in fact, one of our guys tested an A2630 with a 50MHz math chip, and in that the A2620 uses the same math chip logic, I would expect a 50MHz FPU to work OK). The CPU and MMU, however, get their 14.3MHz clock from the A2000 motherboard. These parts work as one, really, so you couldn't even think of making an A2620 go faster than it does without the corresponding increase in MMU speed. The main problem, though, is that the A2620 interface logic counts on being locked to the A2000 clocks, and would require some redesign to work with an arbitrary asynchronous clock. >Yes. From what I heard from both Commodore and AmigaWhirl/World >(FluffMag) you can speed up the board just by adding the new chip(s) and >the oscillator. The board in the AmigaWorld "tips" column was the A2630, which is designed for asynchronous operation. They upped the clock from 25MHz to 28MHz, not exactly a giant step. And I would expect most, though perhaps not all, A2630s to run that fast, at least at room temperature. There are, after all, timing margins in the A2630 to account for worst case chips and temperatures, neither of which you typically encounter. With some modifications and proper CPU/FPU speeds, it could be possible to up the clock speed to 33MHz on the A2630, but the A2620 clock speed is fixed by design. >-Joseph Hillenburg -- Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests" {uunet|pyramid|rutgers}!cbmvax!daveh PLINK: hazy BIX: hazy Standing on the shoulders of giants leaves me cold -REM
stan@phx.mcd.mot.com (Stan Fisher) (11/02/90)
In article <15494@cbmvax.commodore.com> daveh@cbmvax.commodore.com (Dave Haynie) writes: >neither of which you typically encounter. With some modifications and proper >CPU/FPU speeds, it could be possible to up the clock speed to 33MHz on the >A2630, but the A2620 clock speed is fixed by design. > >-- >Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests" OK Dave... When can we hope to see a posting from you entitled: "How to upgrade your A2630 to 33Mhz." Ahhhh come on Dave... Please?? We can take up a collection on the net from all 2630 owners interested in such a hack and make it worth your while. Stan Fisher - stan@teroach.phx.mcd.mot.com - asuvax!mcdphx!teroach!stan Motorola Microcomputer Division, Tempe, Arizona - Voice (602) 438-3228
koleman@pnet51.orb.mn.org (Kurt Koller) (11/04/90)
teroach!stan@phx.mcd.mot.com (Stan Fisher) writes: >In article <15494@cbmvax.commodore.com> daveh@cbmvax.commodore.com (Dave Haynie) writes: >>neither of which you typically encounter. With some modifications and proper >>CPU/FPU speeds, it could be possible to up the clock speed to 33MHz on the >>A2630, but the A2620 clock speed is fixed by design. >> >>-- >>Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests" > > >OK Dave... When can we hope to see a posting from you entitled: > > "How to upgrade your A2630 to 33Mhz." > >Ahhhh come on Dave... Please?? We can take up a collection on the net >from all 2630 owners interested in such a hack and make it worth your >while. > > Stan Fisher - stan@teroach.phx.mcd.mot.com - asuvax!mcdphx!teroach!stan > Motorola Microcomputer Division, Tempe, Arizona - Voice (602) 438-3228 Or better yet, when will we see a 16-64 meg daughterboard for the 2630 card? Just what are the connectors for, anyway? Kurt "Koleman" Koller - tcnet!orbit!pnet51!koleman