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FPU Options

Posted: Fri Jun 14, 2019 2:26 pm
by dalek
Anyone got a lead on non-relabelled FPUs? I seem to always get ones that don't like >33MHz :s

Re: FPU Options

Posted: Fri Jun 14, 2019 11:44 pm
by PaulJ_2.0
I purchased a couple from here and they both seem fine at 50Mhz:
https://www.ebay.co.uk/itm/202667387551

Re: FPU Options

Posted: Sat Jun 15, 2019 2:10 am
by dalek
PaulJ_2.0 wrote:
Fri Jun 14, 2019 11:44 pm
I purchased a couple from here and they both seem fine at 50Mhz:
https://www.ebay.co.uk/itm/202667387551
Hmm maybe I'm just unlucky - they look like the same generic China warehouse ones that I've been getting (from other sellers).

If you are game, would your rub the surface with some isoproyl alcohol and see if the markings remain or disappear? On mine a rub with IPA and the markings are gone :pullhair:

Re: FPU Options

Posted: Sat Jun 15, 2019 10:02 am
by PaulJ_2.0
dalek wrote:
Sat Jun 15, 2019 2:10 am
Hmm maybe I'm just unlucky - they look like the same generic China warehouse ones that I've been getting (from other sellers).

If you are game, would your rub the surface with some isoproyl alcohol and see if the markings remain or disappear? On mine a rub with IPA and the markings are gone :pullhair:
I just rubbed with IPA and the markings are still there.
You may just have been unlucky. Both of mine are absolutely fine and only just get warm at 50MHz

Re: FPU Options

Posted: Sat Jun 15, 2019 10:55 am
by PhilC
The majority of FPUs I've got from China haven't been relabelled but even then it's about 1 in 3 failures (no boot) so unfortunately it's a case of order more than you need.

Btw, I've had 20s that work at 50mhz.

Re: FPU Options

Posted: Sat Jun 15, 2019 11:07 am
by rubber_jonnie
My personal preference for this sort of thing is to avoid any seller that references China, since its probably an indication you'll be taking pot luck with whatever you're buying.

You might get a 68882 that'll run @ 50Mhz, but you might get something that isn't actually a 68882 at all, and won't work at any speed.

I'd suggest looking for individual sellers who are selling small amounts, and whose other items are also computer related. The seller in that link has a ton of other stuff such as household goods and beauty products that just shout that they are selling whatever they can get their hands on.

I got a pair of 40Mhz 68882s or just £10, both 100% fine, using the approach above.