User avatar
rmadden

Posted Tue Mar 03, 2020 10:28 am

I'm thinking of upgrading my GVP accelerator from a 68ec030 (40mhz) to a full 68030 at 50 mhz. In addition to the 030, it has a 68882 fpu running at 40 mhz. It also has 8 MB RAM.

The question I have is ... if I upgrade the processor to a 50 mhz chip, do I also need to upgrade the fpu to 50 mhz as well? I also read something about the oscillator, which is set at 40 mhz. Would this have to be upgraded as well? If these parts do need to be replaced, what others are there that I need to consider.

I've read some other posts on this site as well as searched on-line for answers but can't really find them.

I appreciate any information.

User avatar
obitus1990
New Orleans, LA, USA

Posted Tue Mar 03, 2020 8:10 pm

Yes, the oscillator needs to be switched as well if you want to run it at 50Mhz. Otherwise it will run at 40MHz with the existing one. The FPU should also be changed to a 50mHz 68882. It may work leaving it as is but will be overclocked, if the CPU and FPU share the same oscillator.

User avatar
rmadden

Posted Tue Mar 03, 2020 8:41 pm

If the oscillator is replaced to 50 mhz, thus boosting the overall speed of the card to 50 mhz, is there a possibility of frying the RAM? I saw this possibility on another board and this concerns me. Thoughts?

User avatar
McTrinsic

Posted Wed Mar 04, 2020 7:11 am

You will probably not ‚fry‘ something. However, it is quite possible that the speed of individual circuits may not be sufficient. Somit could be thatcher whole accelerator might not work.

Some years ago I tried - for example - to upgrade a Derringer 030 (non-platinum) from 40 to 50 mhz.

Didn’t work :).

Cheers,
McT

User avatar
obitus1990
New Orleans, LA, USA

Posted Wed Mar 04, 2020 9:04 am

rmadden wrote:
Tue Mar 03, 2020 8:41 pm
If the oscillator is replaced to 50 mhz, thus boosting the overall speed of the card to 50 mhz, is there a possibility of frying the RAM? I saw this possibility on another board and this concerns me. Thoughts?
I don't think you'd fry the RAM, but, some RAM might not handle the speed increase well. The system becomes unstable, which will manifest itself with random crashes.

I have a 50MHz accelerator in one of my A500s...well, the CPU is 50MHz anyway. If I try to use a 50 MHz crystal in it, the system won't boot at all, but, If I use a 40 MHz crystal, it will. I had swapped out the 25MHz CPU that it came with for a 50MHz a few years back. This card is fully socketed (CPU, RAM, all the GALs, etc), so, the CPU upgrade path was something designed into this accelerator (it sold in a couple different variants with regards to the 030 speed and the amount of RAM it would ship with, and the lowest grade one was designed to be upgraded).

I'm not sure the performance increase in upgrading will be significant enough to offset the risk of rendering the card dead, say, if one of the card's MACH chips doesn't handle the upgrade well.





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