It dose have pull-up on the PDA line, because I use open-drain inverter 74HC05, connection diagram is similiar to the parallel port-iic adapter(you can find it in the linux kernel source tree\Documentation\i2c\busses\i2c-parport file), I remove the SCL read-back line and add a 74HC244 to buffer the RESET signal.

Maybe I will try 74HC245 as you mention. If the pull-up(6.2 KOhm) does cause this problem, it sounds a little strange. I doubt whether LPC9107 works

Here is the schematic(copy to text editor to make it clear):

Device                                                      PC
Side          ______________________________3.3V (+)        Side
               |    |            |    |
              ---  ---          ---  ---
              | |  |
|          | |  | |
              |R|  |R|          |R|  |R|
              | |  | |          | |  | |
              ---  ---          ---  ---
               |    |            |    |
               |    |       /|   |    |
PCL 
----------x-----------o |-------------x--------------  pin 2
                    |       \|        |    |
                    |                 |    |
                    |                 |    |
                    |      |\        
|    |
PDA  ---------------x---x--| o--------x-------------------  pin 10
                        |  |/              |
                        |                  |
                        |   /|             |
                        ---o
|------------------x---------  pin 3
                            \|             |    |
                                           |    |
                                          --- 
---
                                          | |  | |
                                          |R|  |R|
                                          | |  |
|
                                          ---  ---
                                           |    |
                                          ### 
###
                                          GND  GND
                                         
                             /|
RST  -----------------------/ |----------------------------  pin 1
                            \
|
                             \|

All resisters are 6.2KOhm

--- On Sun, 5/11/08, Stefano Panichi <g...@yahoo.it> wrote:

From: Stefano Panichi <g...@yahoo.it>
Subject: [lpc900_users] Re: Building a parallel port ICP adapter
To: l...@yahoogroups.com
Date: Sunday, May 11, 2008, 8:44 AM

--- In lpc900_users@ yahoogroups. com, "leg.strong" <leg.strong@ ...> wrote:
>
> Hi, everybody!
> I am trying to build a parallel port ICP adapter. I think it will be
> quite usefull and low cost.
>
> But I can not read data from the device(LPC9107) , the data line is
> always high when read. What may be the problem?
>
> To get in programming mode the RESET pin has to have a sequence of 7
> pulses after the rising edge of VDD and the RST high time must between
> 1-32us, which is easy to achieve with today's computer. I measure the
> pulse with oscilloscope, the timing falls in that range.
>
> Anybody can help?
> I get the ICP specification from this group, I will post the
> documentation here when the adapter is ok.
> Thanks everybody
>

I think
the parallel port of the PC has pull-up resistor that can
influence the reading. Please use a bidirectional transceiver like
74hc245 to force the state of the line.