Re: [Flashforth-devel] Sending Forth files with macOS over USB

[Mikael N. <mik...@fl...>]

On 2019-11-24 00:14, Tristan Williams wrote:
> The transfer program I wrote takes the last approach.  However,
> originally I was hoping that somehow, through the USB CDC driver and
> configuring (in someway I was not aware of) the USB CDC serial port to
> use CRTSCTS, some emulated flow control would be created and I could
> avoid the byte by byte software handshaking.

Tristan,
On Linux/W7 I can use minicom/TeraTerm to send ascii files without any 
flow control at all.
The USB protocol itself performs the flow control.

The USB buffer on the PIC is 8 bytes max and it is owned either by the 
PIC or
the PC. FF does not release the buffer until it has been processed 
completely.
During the time the PIC owns the buffer the PC USB driver cannot not 
send anything to the PIC.

If the PIC is writing to flash it does not take ownership of the buffer 
until the
writing to flash has been completed. So when the buffer is full the PC 
cannot write more.

So I don't really understand what is going in with OSX.

I know the OSX is more picky in following the USB standard, so it could 
be that the my PIC USB
software lacks some functionality that the OSX expects to be there.

Can you check if OSX logs some errors related to USB_CDC?

Mikael