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Floppy Disk Interface Q&As


This Technical Note contains a collection of archived Q&As relating to a specific topic--questions sent the Developer Support Center (DSC) along with answers from the DSC engineers. Current Q&A's can be found on the Macintosh Technical Q&A's web site.

[Oct 01 1990]

Hard disk drive power specifications

Date Written: 2/16/93

Last reviewed: 3/18/93

Can you give us your suppliers' internal hard disk drive power specifications?


The power budget allocated for each slot or drive bay is *all* that you can depend on.

Apple changes drive vendors all the time! Vendors have the freedom to change their own power draw specs (within the limit of the bay spec, which Apple provides) at any time. If you're trying to find some "extra" power that Apple's stashed away and isn't telling you about, it just isn't there. There's no way for you to know whether a user has changed drives or what other expansion cards in the system are drawing power. The system will work only if *all* suppliers stay with in the allocated budget.

You're doing yourself and your customers no favors if you attempt to run at the ragged edge. If you can't fit your design in the allocated budget, you need a more power-efficient design. Remember that Macintosh users don't all leave their machines empty in a perfectly air-conditioned office. You need to anticipate machines with all slots full running at the edge of the spec in very hot environments. Will your drive stand up to that? Will the Macintosh smoke? Will your customer be happy?

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