The Apple Fool overclocking page is a great resource for clock chipping and overclocking but there's some missing info. The Performa/LC 580 is incorrectly marked as not being overclockable/upgradable. This is not true though since the board is identical to the Performa/LC 630 so the same resistor mod to bring it up to 40Mhz will also work on the Performa/LC 580. The only difference between the two boards is the backplate. Just follow the LC 630 guide on The Apple Fool.
If you're wondering what the extra card is on one of the logic boards, it's the DOS card of the Performa 630 DOS Compatible I have. The mod doesn't seem to affect the DOS card.
If you're wondering what the extra card is on one of the logic boards, it's the DOS card of the Performa 630 DOS Compatible I have. The mod doesn't seem to affect the DOS card.
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