Re: New firmware for PseudoDisk / some problems

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

Alex Freed wrote:
> Unfortunately the idea to make use of the C800-CFFF space occured to me when
> the boards had been already ordered. I was thinking of using it for image
> selection code, but loading that from the SD card works fine.

I designed and built a ROM disk card many years ago and managed to
squeeze a full SmartPort driver into the CnXX space by bank selecting
this area and having cross bank jumps rather like the 32KB ROM in the
Apple IIc. It does make for interesting coding and I never bothered to
make it slot independent. My ROM memory map looked like this:

bank #
0 - Boot Entry/ID bytes, ProDOS boot code, ProDOS & SmartPort entry
points, common return
1 - Initialization + SmartPort specific Init
2 - SmartPort Status
3 - Read Block, ProDOS Init + Status

This was for a read-only card so no need for Write or Format routines.