Parallel Bus Interface

<p>The Parallel Bus Interface, or PBI, is a 50-pin port found on some XL models of the <a href="/facts/Atari_8-bit_computers/aT04N5zR">Atari 8-bit computers</a>. It provides unbuffered, direct connection to the <a href="/facts/System_bus/p1mxHpbb">system bus</a> lines (address, data, control), running at the same speed as the <a href="/facts/MOS_Technology_6502/q9YLwkzm">6502</a> CPU. The 600XL and 800XL, along with the unreleased 1400XL and 1450XLD have a PBI interface.
</p><p>The Enhanced Cartridge Interface, or ECI, is a modified version of the PBI designed to be smaller and less expensive to implement. 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. Placed side-by-side on the back of the computer, devices plugged into both at the same time to provide the same electrical interface as the PBI. The ECI is found on late production units of the 65XE, the 130XE, and the 800XE.
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Parallel Bus Interface open-in-new

Parallel Bus Interface