9600/19200 bps RS-232C Interface for C64/C128 with RTS/CTS support ------------------------------------------------------------------ Using Daniel Dallmann's hack of 9600bps interface method, and a 7404, one can use a high bps external modem with a stock C64. This interface includes rts/cts flow control and 9600bps hack. So it can use 19200 with proper rts/cts timings. Only one IC and two connector is required.Thus, it is easier and cheaper method to go up 9600bps. Nick Rossi's Novaterm 9.6 and Daniel Dallman's miniterm programs support this 9600bps hack. user port RS232 DB25 DB9 description --------- ---------- --- ----------- A & N------------------------+-----------1 & 7 5 ground _____ I B & C & 7------------[2 7]-+ [ ] 2------------------[14 1]-------------3 2 rx [ ] M & 5----------------[3 4]-------------2 3 tx [ ] D------------------[5 8]-------------4 7 rts [ ] 6 __ ___[6 11]___ L __| |___[9 12]___| [ ] K------------------[10 13]-------------5 8 cts [_____] note: IC 7404's pins 6 and 9 are connected eachother. Similarly 11 and 12. User port's pins 6 and L connected eachother. Part List --------- 7404 IC (you can easily find it) DB25 male connector (or DB9 male) User Port connector 2m. 2 line shielded cable. (you don't need this if your modem has the cable) Connector Views (looking at the front faces) --------------------------------------------- user port DB25 DB9 1 1 1 1 1 1 1 1 2 3 4 5 6 7 8 9 0 1 2 3 1 2 3 4 5 1 2 3 4 5 6 7 8 9 0 1 2 \-----------------------------/ \-------------/ - - - - - - - - - - - - \ . . . . . . . . . . . . . / \ . . . . . / - - - - - - - - - - - - \ . . . . . . . . . . . . / \ . . . . / A B C D E F H J K L M N ------------------------- --------- 1 1 1 1 1 1 2 2 2 2 2 2 6 7 8 9 4 5 6 7 8 9 0 1 2 3 4 5 Ilker Ficicilar filker@newton.physics.metu.edu.tr e068214@narwhal.cc.metu.edu.tr ---