Crystal osc for Blizzard A1200/4 + 68882 FPU

[rkauer]

 We have discussed this before.

 The conclusion is: better not run 68882 in clocks ABOVE the CPU clock. No problem if the crystal is 33.33 MHz or integer 33 MHz (1% IS nothing).

 But better put some heatsink &/or a little fan over the coprocessor (it runs very hot, specially the 50 MHz version).

[rkauer]

meega wrote:
@rkauer, I don't quite understand what you are saying.

@Hodgkinson, I see from this that the card does not have a CPU, only an FPU (PLCC) and some RAM, and should already have a crystal. What are you trying to do?

Hello meega, no, I not discuss WITH you, I mean we discuss HERE in A.org putting a coprocessor FASTER than the CPU itself makes the acelerator unstable.

Nothing to worry about RAM expansions with coprocessors, tought.

[rkauer]

I use an overclocked CPU and FPU here. Put a 52 MHz crystal (the original was 50). Heatsinks in both chips, a lateral notebook fan and all runs smoothly.

No need to say there is a minor overclock (4% is almost NOTHING). But gives me a bit more speed, anyway.

BTW: I have a Microbotics 1230XL (PGA chips, who have that metal cover, so put an extra heatsink is a good thing) with 128Mb RAM in here.

[rkauer]

Sold a year ago... :-(