Expert: Gregory Donner - 8/2/2008

Question
amiga A1200 I have a expansion board DKB 1202 8meg ram works fine it has an option for a fpu 68882 plcc to make it go faster I fitted the 68882 and the computer would not boot is there any thing else i should be fitting or changing to activate it

Answer
Hi Stan,

Do you have the original documentation for the 1202? I've been unable to find anything more specific for it on the web other than this page on The Big Book of Amiga Hardware:

http://www.amiga-hardware.com/showhardware.cgi?HARDID=987

I assume you have the MagicMem program installed, seeing as you've been able to use the full 8MB of RAM without any problem.

If you look at the high-res photo of the board on the link above, you'll see an empty IC slot called "XTAL101". I'm just guessing here without official documentation, but I believe this may be where you need a crystal chip to set/control the speed (MHz) of the 68882 chip. I suspect that without it, your Amiga is not booting because it has no timing information for the 68882 you installed.

I have no idea where you could find such a chip--specialized components like this are very difficult to find some 15+ years after they were manufactured, and you may be better off looking for another 1202 that has a 68882 and the crystal chip already installed (you could then swap in the RAM from your current card). eBay.com or Software Hut (www.softhut.com) are two places you could look.

I hope this helps!

Greg