Not sure if it will be of any use, but I wanted to use my Raspberry that was collecting dust in a drawer. I ordered on eBay a RS232 level adapter and installed ser2net on the Raspi following the instructions found here : http://home.budget.net/~klricks/Comp/RPi/Serial.html
Using the Telnet Lite app on the iPad, I was able to access the Z80 Monitor (with ACIA IO enabled on the IOBYTE).
Philippe
