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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: ffastback on January 16, 2009, 07:15:40 PM

Title: Question on FPU for A1200 expansion board
Post by: ffastback on January 16, 2009, 07:15:40 PM

I bought an expansion for my Amiga 1200.

http://www.amiga-hardware.com/showhardware.cgi?HARDID=944

Its the same as the top graphic minus the FPU chip. Its in the mail on its way to me. Can't wait to play with it. Anyway, does anyone know where to obtain the FPU this board can take and how one installs the chip?

Thanks!

Title: Re: Question on FPU for A1200 expansion board
Post by: Miloo on January 16, 2009, 07:36:27 PM

It uses a standard PLCC fpu, I got one a few weeks ago on ebay for £9.
The fpu just pushes into the PLCC spcket.

Title: Re: Question on FPU for A1200 expansion board
Post by: ffastback on January 16, 2009, 08:13:35 PM

Quote

Miloo wrote:
It uses a standard PLCC fpu, I got one a few weeks ago on ebay for £9.
The fpu just pushes into the PLCC spcket.

Thanks Miloo.  How do I find out which chips will work on the card and in OS 3.x?  And which way do you orient the chip?  Is the chip and slot keyed to a certain orientation?

Title: Re: Question on FPU for A1200 expansion board
Post by: countzero on January 16, 2009, 08:36:51 PM

there's usually an arrow inside the socket which points pin 1. Also there is a notch if you look high res (http://www.amiga-hardware.com/download_photos/hawk_4_big.jpg) picture of your board.

you should search ebay for 68882 PLCC. it gotta look something like this (http://page6.auctions.yahoo.co.jp/jp/auction/f70251516)

you can also put a wanted ad on amibay (http://www.amibay.com)

Title: Re: Question on FPU for A1200 expansion board
Post by: Miloo on January 16, 2009, 09:14:24 PM

You can use any speed 68881/68882 PLCC chip, I have a 25Mhz PLCC fpu socketed on my 1200 motherboard and it runs just fine.
It doesn't run at 25Mhz I think it runs at the same speed at the cpu. It depends what speed crystal you have.
They can only be inserted one way as one of the corners is squared off.