MITS 2SIO serial chip?

From: Allison <>
Date: Fri Dec 14 15:28:54 2001

From: Richard Erlacher <>
>The 8250 was a fine chip for the application, though I wonder why they used
>DIP version. There were better choices available, but they didn't want to

In 1981 there was only the DIP version as surface mount was not a widespread
technology yet.

>the serial port board business by putting two of them on the same card, and
>that time serial I/O chips tended to have between 2 and 8 ports on them.

In 1981 they did exist, those with more than two ports didn't have second
source and they werent cheap. The 8274 ( the 8088 bus version of the
Zilog SIO) was about 4 times the cost of the 8250(in the fall of 1981)
though it was a far better part and intel would have loved the business.

What's funny is my Leading Edge Model D PC clone used 8251 and put all
the video, floppy, printer and COM1 on the mother board. In my book the
clones often {but, not always} improved a dumb design.

Received on Fri Dec 14 2001 - 15:28:54 GMT

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