SLOTNFT88 As many of these pins were already implemented as part of the already-existing 30-pin ROM cartridge slots on Atari machines, the XE series re-implemented the PBI to include only those pins that the PBI had but the cartridge slot didn't. Many of the pins in the PBI are duplicated in the 30-pin cartridge slot, so ECI was limited to only those 14 pins in the PBI that were not in the cartridge slot. The Enhanced Cartridge Interface, or ECI, is a modified version of the PBI designed to be smaller and less expensive to implement. The PBI is implemented as a rectangular 50-pin edge connector on the back of XL machines. Black Box - The Black Box by CSS hooks up to either PBI or ECI connection. Atari 1090 Expansion System - Designed to give expansion slots to the XL computers.|Togel Online {Doesn't|Does not|Would not} {Have to|Must|Need to|Should} Be {Hard|Arduous|Exhausting|Laborious|Onerous}. {Read|Learn} These 9 {Tricks|Methods|Tips} Go Get A Head {Start|Begin}.