9600/19200 bps RS-232C 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 each other. Similarly 11 and 12. User port's pins 6 and L connected each other.

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

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