What makes slot 7 of the Apple ][ unique from 1-6 and how was this

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slotxth slot 7 ISA, 11 PCI, 1 PICMGPCI,1 PICMG Backplanes PCA-6120P12 20-slot 7 ISA, 11 PCI, 1 PICMGPCI,1 PICMG Backplanes Segments: 1; Slots: 7 ISA, 11

slotxth The meaning of SLOT is a narrow opening or groove : slit, notch How to use slot in a sentence