This option was discussed early in the thread, its NOT safe you are just lucky!
The reason that it is not safe is that for cmos ircuits it can be very bad to have
the inputs or output active without the vcc being asserted. There is an intrinsic
diode between the inputs and vcc ( its part of the esd protection). If the inputs are driven, you could lose that input due to high current draw though it.
Check any data sheet for most cmos chips and you will see a warning about this issue, if you don’t check any textbook that cover cmos circuit design.
What was posted early is that there is 2 drive select wires, look up the ide spec
I forget the exact wires, and just switch those
Previously, Het Studentje wrote in comp.os.qnx:
{ I’ve made my own boot manager. It’s a final option for you maybe, but I like
{ it.
{
{ Just make a switch on your computer which selects which harddisk to get
{ power. Connect the power-supply of you pc to the switch, the switch should
{ have 4 options, leading to the power-connectors of your 4 harddisks. Now, if
{ you select 1, the first harddisk will get power. If this is for instance
{ your secundairy master harddisk, then your computer will boot this OS. If
{ it’s the primary master, it will run that one. If it’s the SCSI0, it will
{ run that. If it’s the SCSI1, it will run that.
or just is the scsi bios to disable the drives
{
{ I made it when I knew nothing about MBR’s and so, and I wanted to be
{ save…VERY SAVE, with my windows OS, because I had some very important
{ stuff on that disk. I didn’t want to ruin my documents.
a better solution is removible hard drive trays, that is much safer
{
{ It’s very save, saver then any other solution. It’s 30min of soldering the
{ plugs and it’s ready.
NO IT’S NOT THAT SAFE, YOU ARE JUST LUCKY
{
{ HS
{
{
{
–
Pat Ford email: pford@qnx.com
QNX Software Systems, Ltd. WWW: http://www.qnx.com
(613) 591-0931 (voice) mail: 175 Terence Matthews
(613) 591-3579 (fax) Kanata, Ontario, Canada K2M 1W8