A3000D 16MHz question

[kirk_m]

Is it possible to have a skilled technician change the 68030 CPU & Oscillator on a 16MHz A3000D to the 68030 25MHz CPU & Oscillator?

I am running into Z3 issues related to having the 16MHz model.  Autosense Z2/Z3 add on boards either will not be selected to run in Z3 mode, or, the cards will not be detected at all, with my upgraded Super Buster 11 / 16MHz combo.  I could just switch back to the prior super buster chip, but, then my 256M BigRam board will not work, according to the manufacturer.

[CPG]

Don't need to change the oscillator - it's a motherboard jumper change only. I've had really good luck (as in every time I tried) setting the 16mhz model to run at 25mhz.

[kirk_m]

Don't need to change the oscillator - it's a motherboard jumper change only. I've had really good luck (as in every time I tried) setting the 16mhz model to run at 25mhz.

Can you elaborate on which jumpers to change to what position?

[desantii]

I did this before there is. 32mhz crystal that needs to be changed to 50mhz

[jltursan]

Until the last 060 upgrade, my A3000 was overclocked from 16Mhz to 25Mhz, indeed it needs a new xtal (I used a socket to easy handling) and a heatsink over the 68030 just to be safe.

The jumpers were:

J100: 1-2 (old 2-3)
J151: 1-2 (old 2-3)
J152: 1-2 (old 2-3)
J851: 2-3 (old 1-2)

[joekster]

Maybe there were several variants of the 16mhz A3000? From memory, my A3000/16 had a 50mhz crystal. J102(could be off on this one) would determine whether to divide by 2 (25mhz) or divide my 3 (16.67mhz). Of course would have to set the ROM and RAM timings jumpers appropriately as well.

[Acill]

I am mostly sure its only a jumper on the motherboard. Its been a long time, but they are on the big book of amiga hardware data base. Changing the CPU is something I can do but finding the correct one now is nearly impossible. I only see PGA packages from macs and imbedded system floating around. I honestly don't see why you would need it done if you are using a CPU card though. Just  change the jumpers from 16 to 25 mode I believe. Also this thread may help: http://eab.abime.net/showthread.php?p=1098682

Try moving J100 as if you had a 25Mhz and see what happens.

From CS MK2 manual:
Appendix A 'Jumper configurations in the amiga 3000 and amiga 3000t'
"The correct jumper position for the operation of the cyberstorm MK2 for models amiga 3000 and amiga 3000t is according to the basic positions as given in the corresponding computer user manuals.
It is only necessary to check the jumper position in case a different turbo board had been installed before the installation of the cyberstorm mk2"


From the A3000 manual:
Defaults for a 16mhz A3000 (313311-01/-02 (PAL/NTSC) in the jumpers table)
J100 2-3 Quad clock source (Positions: 25/16/ext)
J101 2-3 FPU clock source (Positions: ext/int)
J102 2-3 System clock source (Positions: ext/int)
J103 3-4 FPU CS/BERR (Positions: off/berr/on)
J104 1-2 CPU clock source (Positions: int/ext)

[Matt_H]

The 16MHz model (well, mine, at least) also comes with a 68881 instead of a 68882 FPU, so you'll need to replace that as well for a "full" upgrade.

[Oldsmobile_Mike]

Can you elaborate on which jumpers to change to what position?

LOL.  Some of these comments are hilarious.  "Yes, I know how to do it.  No, I won't tell you how."  It's like working in IT, where every day I have to pick and needle at everyone just to fix their problems... "Oh, you saw an error message, what did it say?" - "I don't know, I just clicked on it."  For chrissake, take a screenshot of it, or a PrtScn, use the Snipping Tool, take a photo of the error message with your camera phone, write down what it said on a Post-It note, anything!  I swear, document, document, document!  :lol: :lol:

Sorry, I have nothing to add to this thread, glad you eventually got the answers you were looking for and that it sounds like an easy change!  

[kirk_m]

I am mostly sure its only a jumper on the motherboard. Its been a long time, but they are on the big book of amiga hardware data base. Changing the CPU is something I can do but finding the correct one now is nearly impossible. I only see PGA packages from macs and imbedded system floating around. I honestly don't see why you would need it done if you are using a CPU card though. Just  change the jumpers from 16 to 25 mode I believe. Also this thread may help: http://eab.abime.net/showthread.php?p=1098682

Try moving J100 as if you had a 25Mhz and see what happens.

From CS MK2 manual:
Appendix A 'Jumper configurations in the amiga 3000 and amiga 3000t'
"The correct jumper position for the operation of the cyberstorm MK2 for models amiga 3000 and amiga 3000t is according to the basic positions as given in the corresponding computer user manuals.
It is only necessary to check the jumper position in case a different turbo board had been installed before the installation of the cyberstorm mk2"


From the A3000 manual:
Defaults for a 16mhz A3000 (313311-01/-02 (PAL/NTSC) in the jumpers table)
J100 2-3 Quad clock source (Positions: 25/16/ext)
J101 2-3 FPU clock source (Positions: ext/int)
J102 2-3 System clock source (Positions: ext/int)
J103 3-4 FPU CS/BERR (Positions: off/berr/on)
J104 1-2 CPU clock source (Positions: int/ext)

Only problem with this is that this board has no jumper 101, and, that there is a lot of misinformation in that thread regarding the proper jumper settings to use the CsMK2.

[Acill]

I can socket the crystal and you can mess with it by using several if you like. Take a picture of your board so I can see it. I don't remember having any of this happen to mine when I used it back in my A3000 days.