# Home Made db9 Null serial cable for tivo?



## luder (Sep 7, 2006)

Just wondering if anyone have seen this...










Can somone confirm if this works ..

can someone check there cables and confirm that this diagram is correct.. i want to check if the wire diagram is correct before i plug this in my computer... thanks


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## luder (Sep 7, 2006)

Okay so i went ahead and did it and thought that a write up wouldn't be that bad so here you go i'll edit this later on...


Things you need:

(This all can be found in Radio Shack)

1/8 Stereo jack
Continuity tester 
Multi-wire Cutting tool 
Sadder gun
Sadder 
E-Tape
Bulletin board Tack
Pen & Paper


And so far the picture of the DB9 was easy to make luckily i had extra Db9 cord and a old pair of head sets.. my ohm reader was in the van and i didnt want to go out that night so all I found a 9v battery, Db9 (Serial plug) Mine had a male and female, and my old Dj head phones, and a light bulb (but, I recomend Ohm testers,continuity tester)..

I needed to know what wire color would work for the head phones so what I did was i cut the wire making sure that i had enough wire then removed the outer casing of the wire reveling three wires.. Green, Red, Copper (colors may very) color now I did a test to make sure that the wires corresponded to the wire diagram (Tip, Middle, base.) So before i start i prep the wires by removing the outer shell revealing the colored wires (Colors may very) then took my sadder gun and touch each wire for 7 sec. then coat the tips with sadder to make sure things work.. 

Type of Audio wires:

There are two types of audio cables 
1.) If the three wires inside have no insulation then that means each wire have a clear coat
(This is doable just take your time with it)

2.)If you remove the outer shell and 2 out 3 wires are insulated there would be no clear coat (If you have this it makes the job easier)


Ohm/Continuity tester and probed Tip, middle, base to find wire color ... On mine my ground wire didnt work on base (Explains why my headphones didnt work) So i looked around and I found extra cords. I found one that had stereo jack converted to audio cables (L) (R) on the side it says Radio shack. So i ended up checking it out I found out that both left and right channel lines had a similar ground wire.. 

So I wrote down the wire color that reached the tip, middle. and the base
(I liked the radio shack wires better easy sadder)

Then with the DB9 I took a thumb tack from my bulletin board and drove it in the female DB9 terminal holes. Then I took my probe and tried to touch the tack and each wire to find the wire color then recorded each terminal..

Then I compared it to the wire diagram and begain rosining 3 wires then sadder to the wires i recorded and took my trusty E-Tape and taped it well it was made...

before anyone go out and do this can someone that owns the actual db9 cord verify that the diagram above is correct .. i don't want to plug this in intill it's confirmed thank you


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## shanew1289 (May 7, 2004)

its right and its hard to damage a serial port unless you have ground problems and the new cable is used as ground.

(IE the computer isnt grounded or the Tivo isnt, thus the cable becomes the ground)

If the ground is noisy (old wiring, etc) the ground could cause a ground loop and affect one or the other.

if you are unsure of the grounding, just plug them both into the same power strip.

I learned this the hard way in college. Me and my roommate played DOOM by serial and I lost my serial port. Good ground is imortant when you hook up a cable with ground.


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## luder (Sep 7, 2006)

shanew1289 said:


> its right and its hard to damage a serial port unless you have ground problems and the new cable is used as ground.
> 
> (IE the computer isnt grounded or the Tivo isnt, thus the cable becomes the ground)
> 
> ...


Great to know that grounding is important.. Wow, over terabytes seems like your running the internet over there ha ha


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## shanew1289 (May 7, 2004)

2.5 is nothing compared to some. 

And mine is all spread out. GL


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## bobrockman (Dec 29, 2009)

Hey there, I cannot find the diagram posted here. Can anyone help. Thanks


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## mr.unnatural (Feb 2, 2006)

A sadder gun? Really? I can't tell you how sad that is.

FYI - plans for Tivo serial cables have been around going on 10 years. Check out the forums at www dot deal data base dot com (one word, no spaces; the link is banned by the TCF software as it's the one place where you can get the real skinny about hacking Tivos) and you'll find probably half a dozen different diagrams for building them.

Here's but one post on the subject (posted 12-18-2001):



> How To Make a Serial Cable
> 
> --------------------------------------------------------------------------------
> 
> ...


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