The cables
  1.  Le câble TI-Graph Link original
  2.  Le câble compatible TI-Graph Link
  3.  Le câble parallèle
- Other cables (including the ones for Atari)
- Interfacing softwares

    You absolutely want those wonderful programs ? So you need to start by building something to link your calculator to your computer.

        Here, you will see how to build two types of cable to transmit files to and from your calculator.

And to make them work, don't forget to download the softwares !

    Note: Cables shown here souldn't damage in any way your computer or your calculator. However, if such a situation happened, I don't accept any responsibility. You use them at your own risks ! For cables ordered to me, please read warranty policy on their photo page.

1. The original TI- Graph Link cable

    The circuit of the one you can buy in any TI-selling store:

Le schéma du câble TI-Graph Link officiel

    Take a peek at what's inside:

Photo côté composants du TI-Graph Link

    Particular marks and voltage drops:

CR1, CR2. CR7 Dessin des trois diodes CR1, CR2, CR7 0.599V
CR6 Dessin de la diode CR6 0.693V
CR8 Dessin de la diode CR8 0.774V
"M1M" 0.213V

    For the circuit, I considered the marked band was the diode's cathod, which seemed to be confirmed by multimeter. However, nothing is said about the diode's type, as markings on surface-mounted components is rather esoteric. We can assume, considering the low frequencies of communication, that standard commuting diodes are OK.

Measured values of components:

R1, R2: 10 KΩ
R3, R4: 5.1 KΩ
R5, R7: 3.3 KΩ
R6: 100 KΩ
R8, R9: 470 Ω
R10: 200 Ω
C1+C2: 10.51µF (It is impossible to measure their individual values, but C1 is polarized and bears the number 10. The second one, followed by an A, indicates the maximum voltage capacitor can support. We suppose then C2 is 0.5µ F.)
U1: LM 339AM (4 ampli-op)

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2. TI-Graph Link compatible cable

    Interest of this cable is to be entirely compatible with TI's Black Cable. The scheme is simple, except if you consider to place it in the smallest case possible.

BCC serial link

Parts list:

2 2N4401 transistors (NPN)
2 2N3906 transistors (PNP)
4 1N4148 diodes
4 100kOhms resistors
2 7.5KOhms resistors
2 meters of 2 wires shielded cable
0.5 meters of 4 wires shielded cable
1 DB9 female plug
1 DB9 hood
1 2.5mm female* stereo jack


    Here too, those who can't build this cable can order it to me, for $15 CDN ($11US, 12), softwares included. It represents a saving of more than 30% on the price of a real TI-Graph Link ! A picture of the prototype with its technical specs...

    Note: There's another cable compatible with TI's software, supported by both PC and Macs, the PICLink, for which plans can be found on my page, or on designer's one

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3. Parallel cable

    Everyone should know it, but I put back the scheme for those who may have the laziness to search it:

    This is the most recent version of the parallel cable, others can be found here

Last version of the parallel cable

Parts list:

2 4.7 kOhms resistors
2 1N4148 diodes
2 meters of 2 wires shielded cable
1 DB25 male plug (or female, depending on your parallel port)
1 DB25 hood
1 2.5mm stereo female jack*

    *why female ? male 2.5mm jacks are difficult to find, more, they're unlikely to plug correctly into calculator communication port without making any modification to case. So it's more smart to plug TI-TI cable into your calculator, then into the cable jack.

    For those who don't know how or don't want to build it, I can send them one, including software on CD ROM (diskette also available; you choose), in exchange for $10 CDN ($7US, 8€). A picture of the prototype with its technical specs... For more information, contact me.

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