I can see there is a FPU PGA socket on the board but can see no mention of populating it with a FPU and I assume the the correct speed oscillator module.
Is there any documentation that describes how to add an FPU?
Thanks
ACA1233 FPU capability
- Mickoz
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Don't Panic. Please wash hands.
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Hello,
Same question here.
Would like to know where to buy PGA Socket to install FPU.
Thank you
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The basic ability to sense an FPU and use it is in every ACA1233 and ACA1233n. However, there is no official support for that. Feel free to install the socket and add a clock (either by installing an oscillator or by closing the solder-jumper if the FPU shall run at the same speed as the CPU).
If you do this, you're on your own. My personal recommendation is to not use an FPU, as hardly any software really requires it. On the other hand, there are tons of fake FPUs on the market, and it is *very* hard to identify them. Sometimes it's as easy as "68881 has been re-labelled to 68882-50" (which is quickly identified with the "CPU" command of every WB installation), but if "CPU" is showing a 68882, you might need several months to find out that it's been re-labelled with the wrong (higher) speed, as failure of these chips only shows in rare cases. Other effects may be that the bus load on the card is increased, and RAM data may not arrive in time at the CPU - random crashes may result if you happen to install an FPU with an older mask set. You might need to disable burst in such a case, which reduces the overall system performance.
I don't think that the small percentage of programs that benefit from an FPU is worth all the risk and instability. In terms of warranty, there is no "risk", but a certainty: If you solder in the card, your warranty will be void. Operating the ACA1233 or ACA1233n with an FPU is outside advertised parameters.
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By the way, there exists a fpu software emu which could probably enable you to use the few software that requires an fpu to run, but actually doesn’t use it. Look for femu and try.
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Hi,
Where is this jumper mentioned in "closing the solder-jumper if the FPU shall run at the same speed as the CPU"?
I will be very much grateful if someone can reply please.
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There is only one solder-jumper on the ACA1233n, it's near the oscillator. In fact, it's the only solder jumper on the whole board
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The last reply was more than 365 days ago, this thread is most likely obsolete. It is recommended to create a new thread instead.
