Hello! I have done some testing with different IEC cables, and it turns out that cables without proper shielding do NOT work well for use between a commodore and a disk-drive, like the 1541.

There are some so called 'high quality' video cables on the market with the IEC-alike 6-pin DIN connectors on both ends, but they have the shield of the cable connected to pin 3, with is ATN in the IEC definition. Due to excessive crosstalk, it will cause serious problems.

So guys, tell me.. where do you get your extra IEC cables?

I make them myself.

I have used those video cables too, never a problem even with disk turbos.. I'm sure I have a couple of them mixed up with the rest in my box 'o cables.

This is an interesting coincidence that you should talk about this right now, coz just today I tested a serial cable I bought from Protovision and it didn't seem to work properly. In the C128 monitor I get I/O Errors #5 and then the directory was garbled up until it worked the next time.

Also, I bought a monitor cable, but it gives a monochrome picture on my television. Why would that happen? Should I sent these cables back?

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Commodore 128 Programmer
City of Kouvola, Finland

http://mydarkgothvampiricplace.endofthe ... Commodore/

Whether you send the cables back is, of course, your own choice. You could check with a multimeter whether outer rings of the plugs on both ends are electrically connected. In that case, it is very likely that that is used for shield in the cable. If not, some other pin is used as shield; in my case it was pin 3, ATN. Pulling ATN low caused other pins to have a large dip, too. This causes fast demo loaders to fail. I could imagine that C128 burst-mode also fails.

What do you mean by "until it worked"? You still got the cable to work reliably?

What I am concerned about is whether I should deliver these cables with the 1541 Ultimate Plus. I never officially indicated that it comes with a cable, though. I am worried that if I do supply the cable, that people would blame the 1541U for not working properly, while in fact it is just a poor cable. The question is, should *I* send my cables back? (I have *many* ).

Hmm.. this is interresting.. I usually get my cables from my infinite storage of vintage crap.. only problem is that I sometimes forget where I place stuff ..anyways, I remember at one point I couldn't locate a cable for a 1541 and ended up just hacking some shit together with regular door-bell quality wires and some paper clips for "plugs". As far as I remember it worked. Problem is that I cant remember if it worked with fastloaders and such. I somehow get the urge to try this out again

If "I" were to decide to ship cables, I would either build them myself or get a contractor you can physically kick in the balls for a bad job to do it for me.

Yes, that was my thought too, but I tested it with 1541. I wasn't able to load GP Circuit that uses n0sd0s. But if I'm having a hard time just loading the directory, there is something badly wrong.


Until I managed to load the disk directory correctly... I'm not ready to call these cables crap yet, coz my understanding is that they are built by a person who knows what he is doing, but I am a bit worried.

I actually ordered a variety of cables, around ten in total, so I will try the other two IEC cables that I got, to see if it's just this one cable that is wonky. But I shall email Förster about the problem.

It would be cool to supply a cable with your cart, so I hope you will work to find a realiable solution and wish you luck with it!

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Commodore 128 Programmer
City of Kouvola, Finland

http://mydarkgothvampiricplace.endofthe ... Commodore/

Actually, loose wires will work considerably better than tightly coupled wires with a shield that is not used correctly (i.e. not as return path but for data).

The field energy that causes adjacent wires to react to each other is far larger when wires are packed together than for separate wires. This mutual influence is called 'crosstalk'. So your paperclip solution isn't as bad as you think! (Although it probably emits more electric and magnetic waves and is more susceptible to picking up any.)

The function of a shield in cables like these is twofold: shielding (obviously), and providing a low-impedance return path for the data signals. In a good cable and connector pinout design, shield is just shield, and each signal has its own return path. But let's not forget we're talking 80's here.

Should you deliver cables that don't work with fastloaders?
Of course not! Dig a hole in your back yard and bury them.

jsaily (on Lemon64) makes these cables. They seem to work. I don't know how the shield is connected, and I haven't tried fastloaders with mine.

I totally agree!

Well, I'm pretty sure there was distinction of shield and signal ground back then - maybe just not for Tramiel... Anyways, I remember using a twin cable for synchronous serial transfer - separate DATA and CLK with their own ground, but I still couldn't get more than 8K per second with a ten-meter cable.

But as memory serves, the cables used the shield for return path. BTW, I tested the two other cables I got from Protovision and they appear to work, so it's just the one IEC cable that is fuxxored, as I suspected - and hoped. Dunno what I'll do with it. Doesn't make much sense to send it back.

http://www.fooman.fi/temp/serielles-ver ... kaputt.jpg

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Commodore 128 Programmer
City of Kouvola, Finland

http://mydarkgothvampiricplace.endofthe ... Commodore/

It would be great to get it back in that "Paras Kebab" paper though

Hahah. I knew somebody would comment on it, but it just happened to be underneath. I have now emailed Oliver Förster three (3) times without an answer - I hope this doesn't mean he won't care about the customer once he's out the door with his stuff...

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Commodore 128 Programmer
City of Kouvola, Finland

http://mydarkgothvampiricplace.endofthe ... Commodore/