# $Id: parport.txt,v 1.3 2001/03/07 08:32:28 abhijit Exp $

The PC parallel port wiring interface
-------------------------------------

There are three IO port base addresses used by the parallel port.
These are 0x3bc (lp0), 0x378 (lp1), and 0x278 (lp2).  You will
need to determine the correct port base address for the particular
port you will be using.

The PC parallel port is a 25-pin DB-25 female connector:  Take a look
at the back of your PC.  It looks like this:

  13                         1
 _______________________________
 \  o o o o o o o o o o o o o  /
  \  o o o o o o o o o o o o  /
   ---------------------------
    25                    14

You will need to identify the pin numbers as shown.  For the EEPROM
burner, pins 1, 10, 14, and 17 are not used.  Pins 18-25 are ground
pins and at least some of them should be connected to the ground of
the burner.

The connector coming from the burner (which will plug into the PC
parallel port) must be (of course) a male 25-pin DB-25 connector.
It should look like this from its front side:

   1                         13
 _______________________________
 \  . . . . . . . . . . . . .  /
  \  . . . . . . . . . . . .  /
   ---------------------------
   14                       25

Note how the pin numberings run in the opposite horizontal direction
for the male and female DB-25 connectors.

To hook up the burner to the PC parallel port, you will need to
obtain such a mail DB-25 connector, preferably the solder type.
Then solder sixteen pieces of 18-inch hookup wires to it.  Using
a multicolored ribbon cable is a good idea to keep things neat.
The other end of the ribbon cable connects to the burner board
with a connector of your choice.

