Wanted: 100 MHz Oscillator

[McTrinsic]

Hi all,

I am looking for a 100 MHz - Oscillator.

One of the rectangular ones, with the silvery "case" and the four legs. Like on most older A500 Accelerators.

I want to upgrade my Derringer / 030 from 25 MHz to 50 MHz.

Or does anyone know a different way to do this?

After all, you can jumper the FPU to run at 50 MHZ, is something similar possible for the CPU???

Have fun,
McTrinsic

[McTrinsic]

Could you please explain?

The Derringer uses a 50 MHz Oscillator for generating 25 MHz and the Derringer Platinum uses a 100 MHz Oscillator to generate 50 MHz system speed.

*is puzzled*


Have fun,
McTrinsic

[McTrinsic]

Thanks for your replies, but I already have a 68030 and a 68882 for 50 MHz.

I bought a 1230 IV for these (anyone interested in a 1230 w/ 16 MB RAm but without CPU and FPU ? ).

So what i need is to get the Derringer to 50 MHz.

For that, I need a 100MHz Oscillator.

The Derringer runs at at 25 MHz right now with a 50 MHz Oscillator.


Have fun,
McTrinsic

[McTrinsic]

Rapid Electronics can supply a TTL Oscillator module which runs at 100Mhz, but it's in the 8-pin-DIL type package, not the 14-pin-DIL that you're talking about.  [...]

Uhm... are really talking about this one?? If I look at the back of the board, I see only four "legs".

Before we delv into that though, I have serious doubts about the chances of this working.  If your accelerator has a 50Mhz clock but the 68030 on board is only being clocked at 25Mhz, then somewhere on the board there must be a 2:1 divisor for the clock frequency.  Most probably you can change that divisor to 1:1 and that would be a much better option.  However, since I am not familiar with your particular board I can't really comment on how or where this is done on the board.

Yeah, that would be groovy. I had hoped someone would be able to do this.

The problem you've got is that you don't know what the clock is actually doing.  For example, the 50Mhz clock could be clocking bus speeds at 50Mhz for RAM access and things, but only clocking the 68030 at 25Mhz.  So, if you go and wap a 100Mhz oscillator in there, you'll be clocking the 68030 at a nice, safe 50Mhz but the bus speeds will be running in overdrive.  This is why finding the frequency divisor and changing it would be a better, safer option here.

See above. I do know that is the "system" speed of the oscillator, though.

Anyway, I'll keep looking at electronic shops.

Thanks a lot for your help, though!!

I'll keep you updated in case I am able to make some progress.


Have fun,
McTrinsic

[McTrinsic]

Conrad.de seems to be well equipped with all kind of these Oscillators.

I'll get one there, and need to find someone who can do this for me

Thanks a lot!!


Have fun,
McTrinsic

[McTrinsic]

Thankls a lot for the offer, but I come from Germany.

I'll try to find someone soldering skills.

I hope it's not too hard to do.

On the other hand, I first have tio find a 68882 for 66 MHz before trying to overclock. The one I have was made for 40 MHz but was tested at 50 MHz...


Have fun,
McTrinsic

[McTrinsic]

ok, I got a problem...

replacing the oscillator was sort of easy.

unfortunately, two of the legs broke during transport,

and the cable adapter a friend of mine made doesnt work.

The caps-lock LED briefly flickers when switching on the machine, but thats it.

The problem is, where do I find such a connector?

i am talking about the legs of the accelerator that connect the Derringer to thr mainboard and that are soldered in with the other legs in the derringer. I hope you understand me.

I think the person I know is able to replace them, but I need replacements (another accelerator has the same problem...!


Have fun,
McTrinsic

[McTrinsic]

Additionally, I am surprised that the Derringer I own does only have one cable on its back, not more like the others do... should I worry bout that??


Have fun,
McTrinsic

[McTrinsic]

I know that page, but assumed the difference was lying in the platinum / not platinum thing.

Still searching for those pins...

Have fun,
McTrinsic

[McTrinsic]

Never mind, I finally found some at reichelt.de and schuricht.de.

I will have the broken ones replaced ansd then see what will happen.

Have fun,
McTrinsic

[McTrinsic]

It worked!!

Well, at least it looks like...

The 50 MHz oscillator was replaced by a 100 MHz Oscillator.

The machine boots and is stable for a few minutes, with no exceptional heat generation during this time.

There are other things that need be fixed, though, so I will give a more or less complete overview ina few weeks...


Have fun,
McTrinsic