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.

[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?

[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.