by AltairClone » December 4th, 2015, 11:52 am
Please give me opinions on the following potential firmware updates:
If the option to load/save floppy images over the 2nd serial port is implemented (operator interface remains on port 1), then an option must be provided to choose which port should be used. Should this choice be requested 1) each time a transfer is done, or 2) should it be a saved parameter (like floppy transfer baud rate) that is specified/changed in a separate menu?
Higher baud rates than 115.2K are possible for disk image transfer. Unfortunately, the baud rate error at 230.4K and 460.8K is large enough that the transfer typically doesn't work. Based on the PIC24FJ's clock and baud rate generator, the actual baud rates are 235.3K and 444.4K. These rates will work if you can figure out how to get your terminal emulator/USB-Adapter to work at those rates. You cannot choose these odd baud rates directly in TeraTerm, but I have found that if I update the baud rate macro I provided with TeraTerm to specify 444,444 baud, that when the macro is activated, the baud rate is set to 444.444 and file transfer works (using a PL-2303 based USB adapter and their Windows driver). The complete disk image transfer only takes about 10 seconds. However, the same setup doesn't work for me at 235.3K baud due to unknown magic in the Windows driver. Looking at the source for the Linux driver for the PL-2303 this should work, but I've never seen the source for the Windows driver.
Initially, I was wondering if it was worth adding these two odd-ball rates to the floppy transfer rate menu, but now that I think about it, there's probably no reason not to add them. For example, if someone is using a Pi or Arduino, custom configuration of baud rates is more feasible and this might prove handy.
Feel free to chime in with thoughts.
Mike