Re: How do I add firmware to a card?

["David Wilson" <mcs6502@gmail.com>]

mdj wrote:
> As an extension, or 'nice to have', it'd be nice if the firmware, and
> indeed the uC itself could be programmed from the Apple II. This would
> make it trivial to issue updates to the card to allow for more devices,
> and by association provide a blueprint design that others could use to
> create whatever esoteric hardware interface for the Apple II they
> desired, as all the tricky Apple issues would be taken care of, and all
> they'd have to be concerned with was programming the uC and interfacing
> (via it's spare I/O channels) to whatever it is they dream up.

1) Use a 5v flash chip for the firmware to allow updates.
2) The UniDisk 3.5 uses the following Smartport calls to allow custom
code to run on the 65c02 in the drive itself:

$05 Execute - the 65c02 runs the subroutine previously loaded into its
RAM passing the register contents to be used
$06 SetAddress - tells the UniDisk 3.5 where to put the code
$07 Download - transfers code into the UniDisk 3.5 RAM

The same idea could be used here (especially if large amount of RAM
available).