ZN writes: > >However, all I want is an extra connector on the cable and a switch to > > toggle power to either the one device or the other, ie nothing worth > > $39 + p&p and a big box. > > You may not want it, but it's the only correct way to do it. Switching the > power supply will eventually do damage to either of the devices and/or the > Qubide (probably the latter) if it works at all. IDE devices are not > hot-swap, in other words, input signals should not be present when the > device is not powered up. Before you point it out: yes, there were a couple > of products that actually did this (usually 5.25" removable drive bays). > Ask yourself why you can't buy them any more... > > It is possible to only implement a simple select switch but not just by > adding a connector to the cable - two pins need to be switched and pulled > up to 5V when out of coircuit for both devices that are switch selectable. > Even so, it would not work unless the system is powered down (merely > resetting may not be enough) and the software detected new devices.
Not interested in hot-swap in this instance. The selection was to be made at switch-on time, as I find I rarely use the CD-ROM in qdos/Smsq and rarely use CF in Linux, so depending on what I intened to do, Id choose one or the other on switching on the machine. The alternative, as I see it is to get hold of an ISA riser and a second IDE card. Much more flexible too - but at a price. However, your answer was the one I was looking for: It is not enough just to switch off the power as other signals on the IDE cable will upset the devices somehow. Thanks for that. Per
