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Audio/Video 5 or 8 pin DIN for C.A.T.S (Commodore/Atari/Ti99/Sega)

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#1 seastalker OFFLINE  


    Chopper Commander

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Posted Wed May 15, 2019 8:02 PM

I thought a comparison was in order for everyone on what is known as the DIN connector.  There is a 5 pin and an 8 pin I know about. I hope this thread will bring future retro gamers here to help protect their vintage gear from frying by what looks to be compatible but what actually might have a 5v line in it etc. just waiting to do some damage if not careful.  Consider an addendum to this thread a comparison of DB9 connections for game controllers.


So, what about CATS? Perhaps I should say "C.A.T.S" or Commodore, Atari, Texas Instruments and Sega... their hardware all share a DIN connector, but with some differences in the pin layout. Please see the attached pic (and still photo credits below).


                                                                                                   Some observations~


Commodore 64: 5pin vs 8-pin!!
** As far as cables go, a 5 pin cable will work fine on an 8 pin C64 out, because the first 5 pins are identical on BOTH.  The 8 pin version adds VERY little: Top pin 7 (on right) is N/A, Top pin 8 (on left) is N/A [or 5v DC], so the ONLY interesting pin is the middle pin 6 which is CHROMA.
Atari 5 pin cable NOTE: Pin 5 is CHROMA, but only in theory.  In the XL series, Chroma is not connected without modding. [SAVE this info for TI99 comparison!!]. Pin one is Luma, but WITHOUT chroma connected too, I doubt it is used, and instead favors composite on pin 4 for video out.
Atari 5 pin vs Commodore 5 pin cable (see above notes on extraneous 8 pin version):
**Identical except for PIN 5!!  Atari = Chroma while C64 = Audio IN!!
Atari 5 pin vs Texas Instruments TI99/4A: in short - IDENTICAL AND COMPATIBLE CABLE!!!
The ONLY differences (which will NOT create compatibility problems): Pins 2,3,4, are the same on Atari XL and TI99/4A! TI99/4A ignores pins 1 and 5 (1=luma and 5=chroma on Atari) so in a nutshell: XL and TI99/4A are identical in function with the same composite video, audio and ground; BUT*** Atari, IF s-video is modded, it takes advantage of pins 1 and 5 (chroma/luma) while the TI99/4A does not have the option. [There is a mod that gives the TI99 HDMI though!!]




*****Credits go to:


COMMODORE: Jan Beta for the Commodore handwriting (and HAND). [I hope he does not mind],

ATARI: Bryan (of S-Video UAV mod fame) for Atari,

TEXAS INSTRUMENTS: 99er.net for TI99 diagram

SEGA:  Youtuber "bobexr3" for his Sega Genesis/Megadrive S-Video cable diagram.





I welcome ALL discussion to this topic from if I am blatantly incorrect on any detail, additional observations, etc.  My goal is to create a thread for some who may have multiple systems, but do not know what cables are compatible with others, and if any cable on one system may have a danger of frying another one if blindly experimenting.  It would seem if you have Atari cables, a basic 5 pin din/rca composite cable should work on a TI99/4a for instance.


***What cable combination might HURT your hardware if not careful?

#2 carlsson OFFLINE  


    Metagalactic Mule

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Posted Thu May 16, 2019 1:53 AM

Here is a picture explaining pretty much all that you wrote about:

You are right that the use of pins 2 (ground), 3 (audio) and 4 (composite video) is universal across the majority of Atari and Commodore systems, the /4A version of the TI and even the SVI-318/328 series.

Sega though outputs video on the pin the other use for audio, and its own audio is on pin 1 that on the other systems has Luma or +12V. IIRC a couple more consoles may have a similar DIN output to the Sega.

#3 seastalker OFFLINE  


    Chopper Commander

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  • 212 posts

Posted Fri May 17, 2019 4:11 PM

Thank you for the additional graphic! Very uniform and concise. Interestingly, there are some differences between my information and yours (not that all my sources are correct). Obviously, when searching for these pin layout images, the first thing to ask is if the image is of the device output or the mirror reverse of the CABLE. This is likely why your Sega pins and mine are mirrored. Atari is the same on both. Commodore and the Ti99 get interesting:


Ti99 - Pin 1 says unused on mine where yours shows pin 1 as +12V


Commodore 64: That +5v on your pin 7 (Pin 8 in mine from Jan Beta) Jan indicates it is DC and not AC. It's a shame Commodore has pin 5 as audio IN instead of Chroma (would have been nice to hot swap cables with Atari)


Can someone explain the +12v or +5v etc. as seen on such cables? Are they all DC or are any AC? Regardless, I have yet to learn why the need for either AT ALL when all devices have a separate power cord/input. Is it a signal boost that is intended? I know that Atari and Commodore POWER cords are not compatible and can damage your vintage gear.  Does any mix and match combo occur with these AV cables that could cause damage? 


That C64 audio IN is an odd duck too. How could the cable plug into both an av input and output at the same time?


I have noticed with Commodore cables from ebay that the color coding is all over the place. When trying to sort which from which, both Luma and Composite both seem to work fine as composite video. I don't know if there is much practical difference between luma and chroma except perhaps when you need to pair with chroma for S-Video connections.

#4 carlsson OFFLINE  


    Metagalactic Mule

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Posted Yesterday, 3:51 AM

Those output voltages are DC and mainly used to power RF modulators. The VIC-20 which is not part of the illustration, has +5V on pin 1, the same pin where the TI-99/4A has +12V and the C64/Atari has Luma. You should not connect anything that draws a lot of power to those pins, perhaps in the range of 10-20 mA.


Also if you consider a cable with a DIN plug in one end and multiple RCA plugs in the other end, it doesn't seem so odd to have audio input on the same cable as video and audio output. Many C64 users however tie that pin to ground to reduce buzz, and it is normally not used. If you want a challenge, look up the Microbee 32 computer. It has a 5 pin DIN that carries 9V DC input, monochrome video output, cassette load and save and a common ground pin. You need a small octopus of a cable to use it.


Usually you'd only get black and white signal from the luma, but possibly some of the composite video is leaking so you get a little colour as well.

Edited by carlsson, Yesterday, 3:53 AM.

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