its concerning a Dell Optiplex 780, there are 2 slots next to the video card's PCI x16 slot, which are named slot 2 and slot 3(the video card's slot is named slot 1), but I don't know exactly what they are for, can someone please help me?View attachment IMG_20201024_200907.jpg View attachment IMG_20201024_200921.jpg
Those are PCI slots. Developed from IBM standard called MCA (used in they PS/2 workstations) and VESA Local Bus used in 2nd generation of i80486 motherboards as extensions of ISA standard.
PCI became a standard in Pentium class PCs. Now, I see that in times of integrating everything in CPU, people forgot about this feature which makes IBM PC the most successful computer - expansion cards
The documentation did not help me much. I need to know the exact card that I can put on them. I know they are PCI, but they are not the standard PCI x16(except the first slot of course).