Mobo layout

At some point, I’m not sure when, mobos were reoriented from the left side of the case to the right side, causing extensions such as graphics cards to be redesigned to fit the new layout. I’ve googled anything I can think of regarding it, but I can’t find the reason for the switch. Is there any logic behind it?

And it leads to a problem: I have an older PC and would like to replace the integrated chipset with a dedicated graphics card, but my normal sources don’t have anything for the old layout. Can anyone recommend a source for older parts (US)? I don’t want to spend much, it’s just for testing.

Perhaps you are think the difference between a AGP, PCI and a PCIe video cards? Not sure, but the sockets did change and that is a whole different question. For old stuff, you would be surprised what gets sold on eBay, or even at the Good Will, if that is what you need.

Thank You,

The expansion slots are PCI. However, the mobo is on the left side (from the back of the computer). Graphics cards I find are oriented to the right side. Have a look at the picture. My “new” desktop, about four years old, complies to this. My older computers, both six to eight years old, do not comply. Was there some change in industry standards that brought this on?

As best as I can remember, only the old ISA 8 and 16 bit slots had the cards the other way. I can’t remember PCI going the other way, but perhaps when ISA went away for good, it all got turned.

Thank You,

Do you have any idea what the technical term is for the orientation? It might better help me find something.

Looking back through the annals of time, I found this quote:

It is also notable that PCI slots are “rotated” compared to their ISA counterparts—PCI cards were essentially inserted “upside-down,” allowing ISA and PCI connectors to squeeze together on the motherboard. Only one of the two connectors can be used in each slot at a time, but this allowed for greater flexibility.

I think since ISA went away and PCI became the norm, what you see now is what we have had for a while. I can sort of remember wondering about this way back when, but I have built way more system without ISA than with them.

Thank You,