In the current release of the system, images, text, and programs are fully supported. Audio support is
incomplete. The audio controller functions properly when input samples arrive from a microphone attached
to the FPGA, but when samples come from a wav file, the output is muddy and does not faithfully recreate
the stored audio. This problem was recently traced to a slight inconsistency in sample format and
presentation rate. A stand-alone module was created that can accurately play a wav file preloaded into
main memory, but the important changes have yet to be incorporated with the rest of the system. I
expect that audio will be fully supported in the near future.
The system currently does not support fragmented files. Adding this support to future revisions of the
project will be relatively straightforward. It will involve adding a new routine to the operating system
that traverses the Compact Flash card's file allocation table, and slightly modifying the file list to
store a collection of (fragment address, size) pairs for each file, instead of merely storing the file's starting address. Since
the system is designed for easy software updates and modifications, implementing this additional
functionality will be straightforward, and will require no modifications to the hardware design.