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Classic II FPU card design

maceffects

Well-known member
Maybe someone can correct me but I thought the the speed should match the speed of the processor?  Shouldn’t they be 16mhz/16mhz?

 

moldy

Well-known member
Thanks, I remember some processors used to be really fussy about that. I’m glad this allows for flexibility. 
If you look at my screenshot from MacBench, you can see the results for two frequencies (@16M and @40M; the CPU was always at the default 16M). 40M gives a slight boost to the benchmark score. The card itself has a jumper to configure which clock to use (OSC means the oscillator on the card, SYS is using the C16M signal from the logic board which is 16M).

 

LaPorta

Well-known member
Thanks everyone. So I'd definitely buy one, and hopefully Kai can give us a link to the NOS 40s...I'd be all in!

 

LaPorta

Well-known member
Man, is that shipping ever steep! Guess it would work out if as you said we distributed, but not from the UK I sould suppose.

 

Paralel

Well-known member
I am currently working on a derivative of this design that would support the 50 MHz part 68882. It's a PGA, which is the only major difference between it and the rest of the 68882 series. The only reason is "because". Sort of like most of the projects for 68k Macs.
 

tashtari

Well-known member
Any good place to get one of these assembled? A Classic II recently came into my possession and I'm interested in giving it toys, but my soldering skills are pitiable.
 

moldy

Well-known member
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