doug-doug the mighty's blog

The Eudimorphodon Challenge: Builiding a PCI interface card for the Quadra 950.

The purpose of this blog is to document my attempt to answers Eudimorpodon's challenge to my bug mouth in respect to a post in which a member asked if it were possible to get USB on a NuBus Mac. My response was that it was possible, but would be challenging. Others added insight on the arguments for and against.

Pinout info for the Revision A iMac's 'mezzanine' (aka PERCH) connector

The first version of the iMac had a strange connector on the underside ot the motherboard. A manufacturer for the connector (and subsequent mates to it) is Molex and the part number is 52760-1609. The original purpose of this port was to connect a logic analyzer and quickly diagnose board problems. It was intended to make servicing the boards easier. It was never intended at any time for an upgrade card, and thus, the PCI loads were calculated for that board with the intention of no real PCI load being present. As such there are pull down resistors on the board to 'tune' the performance of the bus for not having a load on the connector

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