Re: 3.5 unidisk

[mdj <mdj.mdj@gmail.com>]

On Feb 26, 7:34 am, demp...@actrix.gen.nz (David Empson) wrote:

> In the case of the UniDisk 3.5, the same procedure is followed but it is
> done by the processor inside the drive. The computer has to select the
> UniDisk 3.5, send a command packet, then the UniDisk 3.5 sends a
> response packet. This takes longer than a quick poll of an Apple 3.5
> Drive. I expect the UniDisk 3.5's processor also has a "minimum
> activation period" timer on its LED so it leaves the LED on longer than
> necessary.

Interestingly, the protocol converter implementation on the IIc
supports interrupts, so it was possible in the older implementation to
implement this more efficiently. Unfortunately I think the external
interrupt pin was re purposed in newer machines, perhaps for head
selection on the dumb-but-faster Apple 3.5" drives.

Does anyone know if the LIRON card implemented external interrupts
like the IIc ?

Matt