Unitech PT600, Programming Reference Manual, Page: 56 / 77

5D
Send Data to RS232 Port in MULTIPOINT Protocol (Buffered
Output)
---for Host Port Control
Entry Parameter: AH = 5DH
DS:DX ; pointer to buffer with output data (max. 256
bytes)
Return Value: AL = 0 ; successful
1 ; failed (output buffer already has data to be sent)
Note: 1) Only for MULTIPOINT communication protocol
2) PT600 will send data out when polled by Host computer
Example :
int TC_str_O(unsigned char *str,int wait)
{
do {
segregs.ds = FP_SEG(str);
regs.x.dx = FP_OFF(str);
regs.h.ah=0x5D;
int86x(0x21,&regs,&regs,&segregs);
return(regs.h.al);
} while (wait && regs.h.al);
return(regs.h.al);
}
5E Check RS232 Output Buffer Status in MULTIPOINT Protocol
---for Host Port Control
Entry Parameter: AH = 5EH
Returned Value: AL = 0 ; output buffer is empty
1 ; output buffer has data
Note: 1) Only for MULTIPOINT communication protocol
2) The function can be used to check if data has been sent to
Host computer.
Example :
int TC_ready(int wait)
{
do {
regs.h.ah= 0x5E;
int86(0x21,&regs,&regs);
} while (wait && regs.h.al);
return(regs.h.al);