How to Make Ti-83 Cable
By Mark Robinson
The Texas Instruments TI-83 graphing calculator features the ability to connect to a personal computer with the use of a separately purchased connectivity cable. The cable allows programmers to upload applications and other content onto the device, as well as program the calculator to perform functions that are not normally available as standard features. Those wanting to save money on peripheral equipment can create their own TI-83 cable from scratch.
Creating the Calculator End
Insert the 2.5 mm stereo jack into the calculator's port. If the plug does not fit flush with the port, remove a small portion of metal from around the base of the plug with a metal file.
Set the multimeter to ohms and determine the voltage of each wire. Probe each ring on the stereo jack tip, then probe the corresponding wires coming from the jack. Use this information to keep track of the wires' location within the cable. Reattach the plastic cover onto the stereo jack.
Remove the plastic cover from the 2.5 mm stereo jack. Strip away some of the cable on the jack and the three-core electrical cable. Solder each wire from the cable to each connector on the jack. Connect the ground wire to the copper mesh on the stereo jack.
Place the wires through the connector rings and place them back into the stereo jack. Reattach the plastic cover onto the stereo jack.
Creating the Computer End
Solder one diode onto pins 13 and 3 on the D-type connector. Solder another diode onto pins 12 and 2.
Solder one end of the 1k ohm resistor onto the leg of the diode at pin 13. Repeat the procedure with another 1k ohm resistor with the diode at pin 12.
Strip the three wires in the cable. Solder the ground wire to pin 22 on the D-type connector. Locate the wire that corresponds with the voltage found on the top ring in the stereo jack and solder it to the resistor connected to pin 13.
Locate the wire with the same voltage as the middle ring of the stereo jack and solder it to the resistor connected to pin 12. Use the multimeter to locate the correct wires.
Add insulation in between the diode and resistor legs to prevent shortages. Attach the plastic cover around the D-type connector.
Plug the 2.5 mm stereo jack into the receptacle on the TI-83. Insert the D-type connector into the parallel port on your computer. You can also use an USB-to-parallel connector for greater compatibility, if necessary.
- Exercise caution when operating the soldering gun. Mishandling the device can cause severe burns.
Mark Robinson is a freelance graphic designer and writer. Since 2008 he has contributed to various online publications, specializing in topics concerning automotive repair, graphic design and computer technology. Robinson holds a Bachelor of Science in graphic design from Alabama A&M University.