On Tue, 11 Feb 2025, Christopher Zach via cctalk wrote: > 16450 was the one with buffer issues
The 16450 was hardly different from 8250: "The NS 16450 is an improved specification version of the INS8250A Universal Asynchronous Receiver/Transmitter (UART). The improved specifications ensure compatibility with the NS32032 and other state-of-the-art CPUs. Functionally, the NS16450 is equivalent to the INS8250A." The broken-FIFO one was the short-lived 16550, while 16550A was the fixed one. Also I do believe it was NS, having been guilty for the broken FIFO, that only used the 16550 vs 16550A terminology and other implementers just called their functional-FIFO parts 16550, which is why people commonly say 16550 having one with a FIFO in mind. Maciej
