What is the Crystal oscilator? Is it in the RAM/CPU expansions?
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A Crystal oscilator regulates the speed of CPU's if you have a 50mhz 060 you can use a 50mhz cystal or overclock the chip with a higher crystal. I never understood completely but if you look on your A1200 motherboard, next to the ROM sockets is a Silver chip. Mine says it is running at 28.37516mhz. That is a crystal oscilator. For a more detailed description of a crystal oscillator goto http://en.wikipedia.org/wiki/Crystal_oscillator. It doesn't explain the relevance of crystals with Amiga but essentially it regulates the speed of the CPU.
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It is what provides the clock cycle for the CPU. They look like this:


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They are also used to control the speed of the FPU on an accelerator card. As mentioned you can get a faster crystal to overclock them. But a word or warning, because overclocking an FPU can burn it out. Same with CPUs. It's a lottery as you won't know if you have a chip capable of being overclocked until you try.
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The crystal for my 030 FPU has fallen out, the CPU one is still there. Will this cause my FPU to stop working? It's on my old A1200, which has sat in a box for a few years...
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What accellerator board are you using? I think the blizzard has a single crystal for both but if it is a different type with seperate crystals then the either the FPU won't work or the board won't work.
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I wouldn't recommend trying to run it until you replace the crystal. It might be OK and just disable the FPU, but equally it could damage the accelerator trying to run it with it missing. You should be able to get a new crystal cheaply.
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Thanks for the replies, i'll get a new chip first.

It's a microbotics 1230XA 030/50 the crystal was always loose, as I remember.

http://amiga.resource.cx/exp/mbx1230
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Amikit usually have a good selection. Never seen those boards before but looks as though it's designed to work without FPU and oscillator so should be fine however always best to err on the side of caution.
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ahh the classic Osc. where would life and blue tooth be without it today.

indeed, An Oscilator takes a charge from capactors or discrete source and then releases that charge as a pulse.. this pulse is essentialy a master CLOCK tic.

Not all CPU's will use this clock directly. for instance, the 040 would use this TIC and on every secondth would shunt data about.

Imagin it this way, every TIC(pulse), of a 50mhz crystal (thats one pulse every 50 thousandth of a second) would be a direct 1 to 1 translation for an 060, but on an 040 its is devided (this is internally for its fetching or registers and functions etc) by 2 thus only on every other TIC (a TOC we could say) would it receive input or send output.

infact Most CPU's today use an external clock only to govern access times to other chips / controlers like memory / buss boards etc. In the Amiga hardware its a little simpler, but essentially the same thing.

by not having a Oscilator connected it wont damage your components, infact its most likely it just plain wont work without it. as it receives no timing pulse to do any work LOL

as mentioned before Amiga Kit have a good range of Oscilators and havae a great service! I would recomend them... if they dont haver the Osc. you need gimmie a shout... i have a fair few
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