blackcat cable schematics

xman1001 · 31st December 2004, 11:36 PM

do we need a new jkey deff to clone the modem?

**blackcat cable schematics -** 5th June 2005, 10:27 PM

if any of you are into the cable modem cloneing scene , i need your help ...

tcniso sells this "blackcat cable" which is basically a jtag cable that connects to the parallel port at the PC end and to the modem at the other end ... if anyone has this cable can you make schematics for this ?

the modem is the motorola surfboard 5100 ... it has a jtag port with 2 rows of 5 solder points .. i'm not sure if there is a schematic of the modem online somewhere that will list which one of the points on the jtag are for what function ...

here is a pic of the modem jtag

http://img229.echo.cx/my.php?image=5100ejtag0fn.jpg

Psy_Snoop · 6th June 2005, 12:36 AM

I don't have the cable or modem but looking at the picture you can eliminate the top row, thay all seem to be ground. So there aren't many left to figure out.

6th June 2005, 04:56 AM

here are a couple of pics from the actual jtag cable ... i wonder if the SN74 chip, which is a driver/buffer chip can be entirely eliminated to simply the job ?

http://img299.echo.cx/my.php?image=side12xb.jpg
http://img299.echo.cx/my.php?image=side29vo.jpg
http://img300.echo.cx/my.php?image=dscf03414ed.jpg

6th June 2005, 06:40 AM

**anyone get scamatics all set -** 14th June 2005, 10:13 PM

did anyoen get the final scamatics all up yet ?

03:17 PM

Hey, I know it's a little late but here's the schematics, I made this cable but without the bit labeled SN74LS244N, I was wondering what this part is for, it was labeled I.C somewhere else and when I searched for the reference number it came up as Octal Buffers And Line Drivers With 3-State Outputs

I have deleted the url and attached the image to the post. Image hosting site displays pornographic material along with image.

US_Cybernaut (Super Moderator)
Interesting-Devices Ltd

lvdennis · 26th June 2007, 06:05 PM

I built this with the 74ls244 and couldn't get it to work. You said you got it to work without using the IC? What did you do? Tnx...

niknak · 25th July 2007, 08:33 PM

Just looking at the cable pix and schematic I may see a problem. The schematic is not clear where you get the VCC +5vdc and Ground from to power up the chip. The picture looks like pin 20 VCC goes to a land that then goes to the DB25 connector (pin 4 I think). If the chip isn't working you need to check the +5 vdc voltage between pin 20 VCC on the chip to pin 10 ground. I don't know why they referenced "USB" for the voltage source supplied to this chip? Bet you don't have the power for the chip is my concern. This device is tristate driver which means they can phantom OR it's outputs without hurting the input logic signal So when you eliminate this tristate chip you could be hurting some input logic elements that can't stand Phantom ORing of it's output pins (inputs to this chip). Phantom ORing pulls down all logic element I/O to ground if this logic level line goes to zero. Some chip outputs don't like there output shorted to ground that's why they use this tristate chip. The chip allows ORing and also provides logic level power to drive heavy input loads tied to it's output. So if you ask, can you jumper arround this chip? Maybe but not suggested!

I just looked at the chips schematic and the chip is also an inverter so it can't just be jumpered .... The chip also can drive approx. 24 milliamp loads therefore I don't suggest putting that big of logic load on the circuit prior to this chip! So fix the problem to get it to work as designed is my suggestion. A very simple task if you got a voltmeter or a logic probe.

niknak

lvdennis · 26th July 2007, 05:02 PM

I checked for voltage like you said and I do have it. While I was at it, I traced the entire circuit with a fresh set of eyes and we both agree that I created it identical to that schematic. The usage of the USB is for a regulated +5, which I was using, I even pulled out my variable power supply and still the same results. Perhaps its a fake, or someone deleted a trace from it; or, the schwatze (sp?) that I have is a fake. Any other ideas? And, does anyone have any alternate circuits for this programmer? Tnx...