Multiplexing a string of letters using the parallel port
A month ago, i asked [this][1] about multiplexing a string of numbers with 4 7-segment displays. But now, i'm trying to update the code to multiplex a string of letters using 7 7-segment displays in python. 

[This is the new circuit.][2] When i send data using the parallel port, the Latch Enable recives the most significant bit (pin 9). In the second latch, the Latch Enable recives it also but negated, that is the reason of the 7404.

The 'X' represents that the 7-segment display is off.

    XXXXXXX
    XXXXXXS
    XXXXXST
    XXXXSTA
    XXXSTAC
    XXSTACK
    XSTACKX
    STACKX0
    TACKX0V
    ACKX0V3
    CKX0V3R
    KX0V3RF
    X0VERFL
    0VERFL0
    VERFL0W
    ERFL0WX
    RFL0WXX
    FL0WXXX
    L0WXXXX
    0WXXXXX
    WXXXXXX
    XXXXXXX

That would be the output for the string "STACK 0V3RFL0W".


  [1]: http://stackoverflow.com/questions/9919550/multiplexing-string-of-numbers-in-python-for-the-parallel-port
  [2]: http://i.imgur.com/0QUwn.png
Multiplexing a string of letters using the parallel port
===

A month ago, i asked [this][1] about multiplexing a string of numbers with 4 7-segment displays. But now, i'm trying to update the code to multiplex a string of letters using 7 7-segment displays in python. 

[This is the new circuit.][2] When i send data using the parallel port, the Latch Enable recives the most significant bit (pin 9). In the second latch, the Latch Enable recives it also but negated, that is the reason of the 7404.

The 'X' represents that the 7-segment display is off.

    XXXXXXX
    XXXXXXS
    XXXXXST
    XXXXSTA
    XXXSTAC
    XXSTACK
    XSTACKX
    STACKX0
    TACKX0V
    ACKX0V3
    CKX0V3R
    KX0V3RF
    X0VERFL
    0VERFL0
    VERFL0W
    ERFL0WX
    RFL0WXX
    FL0WXXX
    L0WXXXX
    0WXXXXX
    WXXXXXX
    XXXXXXX

That would be the output for the string "STACK 0V3RFL0W".


  [1]: http://stackoverflow.com/questions/9919550/multiplexing-string-of-numbers-in-python-for-the-parallel-port
  [2]: http://i.imgur.com/0QUwn.png