Ribbon cable from expansion port

[00WReX]

Hi All,

Just wondering what would be the maximum recommended length of the ribbon cable from the expansion port to an 'expansion board'.


Cheers,
Shane

[CraigsBar]

My symbiface is about 30cm away from the back of the 6128plus (due to desk logistics) and it works fine. Although that is the higher limit I believe.

My mx4 on the 464plus is right behind it!

[XyphoesRe]

The Symbiface was sold (and is sold again) with 40cm ribbon cable. But this is really(!) the maximum - we have had some signal problems with this length and so its most a try and error. You should keep it as short as possible

[CraigsBar]

I will soon be ordering a 2nd mx4, as all 4 slots are occupied, and I have an mf2 remake on the way lol.

[Bryce]

In an ideal situation = The expansion contacts are really clean, your 5V PSU is giving a very stable 5V with almost no ripple and can supply enough Amps and all other electronic equipment is well shielded or far enough away, then 40cm could be ok, but there's no guarantee. Problems can start at about 25cm, but because wires act as antennas, there are particular lengths (below 25cm), that if you happen to get it exactly right (wrong), then you will have lots of issues despite being under 25cm.

Bryce.

[TotO]

Shorter is better. Don't forget that is the CPU bus and not a peripheral connector...

[TFM]

Right, the shorter the better. In general it really depends on the expansion. In my experience some are very tolerant others are not.
That's the advantage of the MX4 format, it keeps things close to each other, there is no drive through for 3-4 expansions. Such a rat tail can become a problem.

[00WReX]

Thanks everyone for the replies.

Cheers,
Shane