;19 IN/OUT 00-$3F ROM ADDRESS HIGH
;1A IN/OUT 00-$FF ROM ADRESS ADDRESS LOW
;1B IN 00-$FF READ ROM DATA (ADDRESSING MODE)
</pre>
'''=== ADDRESS:&FF08 OUT TX – AUTO POLLING'''===
If you want to transmit a character in a full duplex or a half duplex communication then you just send the character to the address &FF08 and the flags are automatically checked by the program of the microcontroller!
<pre>
BASIC: A A=X X OUT &FF08,A
</pre>
<pre>
ASSEMBLY: LD LD BC,&FF08 LD LD A,X OUT OUT(C),A
</pre>
To select the type of communication you want to have (full duplex, half duplex or 485 halfduplex), you can use UART REG3.
=== ADDRESS:&FF09 IN RX – WAIT UDR CHARACTER ===