Theoretical max serial speeds

[krebizfan]

Write it to a ramdisk. That would provide the theoretically fastest transfer rate possible with the chosen system.

 

[jlang]

@daver2 "I have always used a x16 divider. But I see there is a x1 divider mode. I wonder what that will do for you?"

Higher speed but now you need to synchronize the clock.
So FM MFM PE... encoding to allow clock recovery. It's not a lot of logic.
Or:
Since the OP was talking short range you could just send the clock on another wire.

 

[Plasmo]

Assuming OP is moving data from RAM of one Z80 to transmit over serial port and the 2nd Z80 is receiving data and stored back in its RAM, and further assume the serial device has deep FIFO like ox16c954, (128 byte TX/RX, all 4 channels) then 460K seems achievable.
Bill
Edit, maybe 460K is optimistic, but surely 230K is realistic.

 

[MykeLawson]

Yep Plasmo, that is exactly what my plan would be, sans the FIFO part of any UART. I'm just thinking of a simple transfer of data, nothing complex. Rx, Tx, and a ground. 115,200 with 2MHz clocks will work out perfectly.

 

[daver2]

I explained the use of the x1 divider above.

Dave