EXTENDED HOSTMODE COMMAND by DG3DBI
The main purpose of the XHOST-Mode is the reduction of unnessecary polling of the TNC and so an increment of speed on the seriell line. There are only very few changes necessary in existing Hostmode-Terminal- programs. E.g. GP support this mode.
The PC transmit the 'G'-Kommando to channel 255 of the TNC An old-fashioned TNC without XHOST will answer with the errormessage "INVALID CHANNEL NUMBER". A TNC using the Extended Hostmode will transmit a nul-terminated string (ASCIIZ) back to the PC. This string contains a list of channel which have already some kind of Info in the buffer. This is also true for the Monitor-channel (channel 0) and the statusinformation (Statusdaten). The channelnumber inside the string are incremented by one, since the null-terminated string wouldn't allow data of channel 0 otherwise.
Example for the answer of the TNC: 0xFF 0x01 0x00 - No Data available. 0xFF 0x01 0x01 0x00 - Some Data are waiting in the Monitor-Buffer. 0xFF 0x01 0x01 0x03 0x04 0x00 - Data in Monitor and channel 2 and 3
Ritorna a Software Radioamatoriale by IW3FQG