MOS Technology 6551

<h2 id="variants">Variants</h2>
<p>The <a href="/facts/Rockwell_Semiconductor/nKcIUc8E">Rockwell</a> 65C52 combines two <a href="/facts/CMOS/NJIWYgBl">CMOS</a> 6551s on a chip.
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<h2 id="similar-chips">Similar chips</h2>
<p>The <a href="/facts/Motorola_6800/0D4BNIha">Motorola 6850</a> is a similar chip to the MOS Technology 6551, but without an onboard bit rate generator.  The 6850 is often used for <a href="/facts/MIDI/tblhmeFV">MIDI</a>.
</p><p>The <a href="/facts/WDC_65C51/WnGB7pu6">Western Design Center WDC 65C51</a> is designed as a drop in replacement for the original MOS 6551, electrically, physically and programming- compatible with most 6551 and 6850 derivatives from most other suppliers.  The WDC 65C51 has errata, in which the transmitter “ready” bit is “stuck” in the ready state.
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<h2 id="external-links">External links</h2>
<ul><li><a href="http://archive.6502.org/datasheets/mos_6551_acia.pdf">Datasheet</a></li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>"MOS Technology 6551 | Semantic Scholar". www.semanticscholar.org. Retrieved 2025-03-15. <a href="https://www.semanticscholar.org/topic/MOS-Technology-6551/1425152" target="_blank">https://www.semanticscholar.org/topic/MOS-Technology-6551/1425152</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
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MOS Technology 6551 open-in-new

MOS Technology 6551