Appendix Interface signals 55 Pin Source Compatibility Mode Nibble Mode Byte Mode 1 Host Strobe HostClk HostClk 2 Host/Ptr Data0 (LSB) Data0 (LSB) Data0 (LSB) 3 Host/Ptr Data1 Data1 Data1 4 Host/Ptr Data2 Data2 Data2 5 Host/Ptr Data3 Data3 Data3 6 Host/Ptr Data4 Data4 Data4 7 Host/Ptr Data5 Data5 Data5 8 Host/Ptr Data6 Data6 Data6 9 Host/Ptr Data7 (MSB) Data7 (MSB) Data7 (MSB) 10 Printer Ack PtrClk PtrClk 11 Printer Busy PtrBusy/Data3,7 PtrBusy 12 Printer Perror AckDataReq/Data2,6 AckDataReq 13 Printer Select Xflag/Data1,5 Xflag 14 Host AutoFd HostBusy k HostBusy 15 NC ND ND 16 GND GND GND 17 FG FG FG 18 Printer Logic-H Logic-H Logic-H 19 GND GND GND 20 GND GND GND 21 GND GND GND 22 GND GND GND 23 GND GND GND 24 GND GND GND 25 GND GND GND 26 GND GND GND 27 GND GND GND 28 GND GND GND