> No more than 5 metres of unboosted cable. (I have a mouse with a 6 foot > cord on the end of a 5 metre extension and it works on a USB2 port but not a > USB1 port) > > Maximum total length is 25 metres with active signal boosters every 5 > metres. (probably to do with bit times and all that coax ethernet timing > stuff from last century.)
Probably to do with basic physics: signal propagation time. It only goes with light speed, but even more hindered by line impedance and the boosters. The whole system is probably designed on the assumption that there is a maximum delay for data from one end to the other. Tolerances and implementation specific characteristics will allow you to push the limits, but somewhere it'll fall over. Use good-quality commercial extension cables and whatever booster you can find. I wonder whether a self-made booster could do the whole 25m or more at once, the commercial ones are probably again designed on the assumption that they don't drive more than 5m. Home-making USB cables is silly because apart from being waste of time when the cables a, uhhm, $5 in the shop, it would give you bad electrical characteristics unless you really know what you're doing and find the right plug construction. Volker -- Volker Kuhlmann is list0570 with the domain in header http://volker.dnsalias.net/ Please do not CC list postings to me.
