You wrote:
>
> * Patrick C Leger <blah+@ANDREW.CMU.EDU> wrote:
>
>
>>I just built an RS-232 powered 16C84 programmer (the one with 1
>>diode, 1 cap, 1 78L05, and 3 resistors), but I'm having some problems
>>with it.  The 78L05 sucks the tx line (and thus MCLR) down to about 7
>>volts, which is apparently not enough to kick it into programming
>
>The 16C84 needs about 10.5 to 11V to switch to programming mode.
>My original design uses a resistor and a Zener-diode, because I had
the same
>problem with the 78L05.
>
>
>     TxD ---*-----------------------------
>     (2)    I                            I
>           ---                          ---
>           I I                          I I
>           I I 2k2                      I I 10k
>           ---         1N4148           ---
>            I       I\I                  I
>            *-------I-I-----*---------   I
>            I       I/I     I        I   I
>          ----\             I +      I   I
>           /\  \           ---    14 I   I 4
>          /  \    5V6      ---   --------------
>          ----         100u I    I  Vdd Vpp   I
>            I               I    I            I
>            I               I  5 I            I
>     GND ---*---------------*----I Vss        I
>     (7)           22k           I            I
>                  -----       12 I            I
>     RTS ---------I   I----------IRB6 (clock) I
>     (4)          -----          I            I
>                  -----       13 I            I
>     DTR ---------I   I----*-----IRB7 (data)  I
>     (20)         -----    I     I            I
>                   2k2     I     I  PIC 16C84 I
>     CTS ------------------I     I------------I
>     (5)
>
>
>
>This should work. If not, try to vary the resistor between DTR and
CTS.
>
> - Erik
>___ Terminate 1.51
>

Do you use a public domain programming package (sw) ?

tahnks,gwk