MODIFICATION TO CHANGE THE STANDARD

	  IBM PCJR LPT1 SIDE CAR TO PORT LPT3

		Charles L. Terra PhD PE
		chuck1953@bellsouth.net

This is a preliminary document:

Step 1:
	Preparing the pins on chips that need modification.
	Using LPT3_1 as a reference...

	You will be clipping the pins, removing half of the pin that goes thru the pc board
	being careful not to cut off the entire pin,you will need to solder jumper wires
	to the remaining portion connected to the chip....
	
	Definition:   VIA :  this is the hole that the chip pin goes in, it make electrical
	contact from the top of the board to the bottom of the board.  I'll reference the
	VIA in this document.


	First using solder wick, remove as much solder as you can, be sure not to heat the
	pins up too much...(A solder sucker is prefered, does a much better job)

        After cutting the pin, clean the via removing any excess solder from the via. You can do
	this from the bottom of the board best.
	Now gently bend the remaining portion of the chip pin up away from the board.  You will
	need to solder a jumper wire in the newly cleaned Via and to the remaining chip pin.

	Using the numbers on the chips...prepare all the chip pins and via's as described above:


	(CHIP 1)   cut and prep pins 5 and 11

	(CHIP 2)   cut and prep pins 4,5 and 6

	(CHIP 3)   You will need to ADD a chip 74LS08 as seen in the picture.
		   You will only use pins 1,2,3,7 and 14.
		   Cut all but pins 7 and 14 leads back, typically in half will be fine.

		   Bend pins 7 and 14 down and solder them to the chip located in the picture
		   directly below the added chip.   This will supply power (pin14) and ground (pin7)
		   to the new chip.  Make sure you BEND out the remaining pins so they do not
		   touch any pin on the chip below....
			
Step 2:
	Adding Jumper wires to the board:
	(note:  ignore the jumper wire labeled Bi-Dir, this is the Bi-Directional mod, not part
		of this documentation.)
	
	Note:  Defintion    Pin - part of the chip
			    Via - hole below the chip pin designated 

	Jumper 1:
		Connect a wire from :

		CHIP 1-pin 5  to CHIP 2- pin 4

		CHIP 1-pin 11 to CHIP 3- pin 3
	
		CHIP 3-pin 2  to CHIP 1- via 11

		CHIP 2-pin 5 & 6  to CHIP 1- via 5


                Important steps to pay attention to here:

		CHIP 3-pin 1  to Connector B7   (See LPT3_2 picture)
		Notes:
			Look at the picture and locate the VIA that the wire goes through.
			This is just to get the wire from one side of the board to the other,
			It DOES NOT get soldered to this via.   Think of it as a doorway....

		(be careful not to place too much solder on the connector pin, it is best to prep the
		 pin by placing a small abount of solder on it first, then with a hot iron
		 just tack solder the wire on)

		
		JUMPER:
 		   Again using LPT3_2 picture, locate the small jumper just above the connector
		   to the left.
		   This is the bottom side of CHIP 2 and will jumper pin 4 to pin 6.

	DONE.

	Check your work before powering up the unit.