Quick update - thanks again Tumbleweed. Now running at 230.4k BAUD.

Time for 256 MB download now at an estimated ~ 11.2 hrs.

The bottleneck will be the handshake as I'm "requesting" each page (256 Bytes) by sending a short stream of characters $$$8xxxxxxx where xxxxxxx is the page number. The PIC waits for the $$$ and then reads the page request value, transfers that page from memory to the PICs RAM and replies with the data. This way it's a very ordered delivery; perhaps too ordered!!!

I think I'll try having it send each block (or whatever its correct term is) of 65536 pages in one long stream (16 of them in all on that memory chip, making 1,048,576 pages x 256 Bytes = 256 MB). Just need to buffer for longer on the PC side. If I get any errors, I can just reduce the number to something more manageable and request corrupted pages.

Will let you know how it goes, and many thanks again!

Best,

Jimbo