MODIFICATION TO CHANGE THE STANDARD

	  IBM PCJR LPT1 SIDE CAR TO PORT LPT2

		Charles L. Terra PhD PE
		chuck1953@bellsouth.net


You can use any program that checks the ports to test your modification.
I did this mod because I wanted to add a ZIP drive to my Jr and wanted 
to have a free (non-ZIP port) LPT for other uses....

I used a program from Klaus Peichl, name:  LPT_TEST.com    this is available on the internet.
This program tests for Bi-Directionality of a LPT port.

Caution:
When using this program, if you only have one Printer sidecar installed, the
the program will report this port as  (  LPT1 H278  ), this is confusing because it is really
(  LPT2  ).  But if you install two LPT sidecars, one standard and one with
this mod it will give the right reports back.....





1:	REMOVE PCB FROM PLASTICS

2:	ORIENT BOARD SO IT IS THE SAME IN THE PICTURE LABELED  (SIDE 1)

3:	LOCATE THE TRACE BETWEEN CHIPS 74LS04 AND 74LS30  (SEE PICTURE)
 
4:	USING A SHARP EXACTO KNIFE MAKE A SMALL CUT TO ENSURE THE COPPER TRACE IS
	REMOVED....BE CAREFUL NOT TO DAMAGE ANY OTHER TRACES.
	IT SHOULD LOOK LIKE THE PICTURE   (SIDE 1)

5:	USING A SMALL 30AWG WIRE, CUT AND STRIP THE WIRE ENDS, SOLDER ONE SIDE
	TO  PIN 2 (74LS04), THEN SOLDER THE OTHER SIDE TO PIN 4 (74LS30).
	MAKING SURE NOT SO 'SOLDER BRIDGE' BETWEEN ANY OF THE ADJACENT PINS.


	MODS FOR SIDE 1 ARE DONE  ....CONGRATULATIONS.....


1:	TURN BOARD OVER	AND POSITION IT AS SHOWN IN PICTIRE (SIDE 2)

2:	LOCATE THE TRACE SHOWN ON THE PICTURE..  (BE SURE YOU HAVE THE RIGHT ONE)
	IT'S BEST TO DOUBLE CHECK AND MARK IT WITH A RED PEN IF NEEDED SO YOU
	DON'T LOOSE SITE OF IT...

3:	USING A SHARP EXACTO KNIFE MAKE A SMALL CUT TO ENSURE THE COPPER TRACE IS
	REMOVED....BE CAREFUL NOT TO DAMAGE ANY OTHER TRACES.
	IT SHOULD LOOK LIKE THE PICTURE   (SIDE 2)

4: 	USING A SMALL 30AWG WIRE, CUT AND STRIP THE WIRE ENDS, SOLDER ONE SIDE
	TO POINT SHOWN IN THE PICTURE, THEN LOCATE THE OTHER POINT AND DO THE SAME.
	(AGAIN IT'S BEST TO MARK THIS WITH A RED MARKER TO HELP KEEP TRACK OF IT.)

		

	MODS FOR SIDE 2 ARE DONE  ....CONGRATULATIONS.....


        YOU ARE NOW DONE AND THE SIDECAR IS SET UP FOR PORT LPT2 PORT ADDRESS  H278



Feel free to pass this along but keep all the files in tack....

Chuck....