I am trying to get this device working on my laptop. I think I know how the port interface works.
The device sends data to the computer and receives data from the computer in 4 bit nibble mode.
The data is input through J7 pins 2,3,4 and 5 and is output via J7 pins 10,12,13 and 15 while J7 pin 14
is used as a chip inable.
Some of the devices receive there power from the local +5v supply while others get there power from
the host parallel port since back in the day 74LS devices were used that could source quite a bit of current.
J7 pins 6,7,8 and 9 are not used for data transfer but are used as +5v supply lines from the parallel port.
R84 10k ohms is used as a pull-up to J7 pin 14 for the enable line to IC16.
If this is not correct would someone please get me on the right track.
You can use this link to download the complete circuit diagram and operation description of the PCS500:
box.net/shared/ybz9k9adq4
Thanks