Re: Apple IIe TCP-IP w/ LANceGS Card

[mjmahon@aol.com (Michael J. Mahon)]

Bill Garber wrote:

>Would it be possible to use the Z-80 on a card
>instead of a 65C02 for a smartport device that
>would connect to the floppy port on the IIc?
>I'm not sure if the Z-80 is easier or harder
>to program than the 65C02, but I am under the
>assumption that the analog card in a UniDisk
>3.5" drive is a standalone computer more or
>less. Shouldn't matter what type of computer
>then in that case. Right?

The card inside the Unidisk 3.5 is a computer--more accurately,
an embedded microcontroller.  It is not particularly important
what kind of processor it is, as long as it has sufficient ROM, I/O
pins, and speed for the task.  (Most embedded system engineers
will choose a member of a processor family that they already
know well and have the tools for, or one they want to get to know.)

I should say that programming such a controller, which must
interface both disk drive hardware and to the smartport interface,
with tight real-time constraints, is a non-trivial task.  Of course,
the faster the processor is and the more ROM and RAM it has,
the less "tight" the code needs to be...  In these days of 20+Mhz
microcontrollers with 16KB of ROM and 8KB of RAM, it could
be programmed in C and get the job done.  ;-)

The problem will be getting a _full_ understanding of the smartport
interface and whatever you want to interface to.

-michael

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