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Support for UART 8250

November 7, 2018 at 16:31:25
Specs: MS-DOS 6
I am trying to replace an old DOS machine with a newer PC. I found a Dell PC from 2003 that had a parallel port for the old printer and a serial port. I needed another serial port so I bought a card for it.
The PC runs scientific equipment communicating through the serial ports. When we hooked up and booted the new machine we got a "comio: 14 warning No 8250 UART installed at I/O address."
My research indicates that the 2003 PC would be too new to have a 8250 UART. I am wondering if there is any way to emulate the 8250 or otherwise get it to work? before I spend too much time on this I was wondering if anyone thinks it is even possible.

See More: Support for UART 8250

November 8, 2018 at 01:40:37
Hi Bear,

it is not clear from your post, but does the original Serial Port work?

I recall that when serial ports where added, it as not always straightforward setting them up as address and/or interrupts might require setting..

The add on card may have straps or dip switches for this purpose..

If the add on card is missing the required uart, instead having a later version, and it has to be the 8250, would think an older add on card may have the required uart.

Some add on cards had more than one serial port..

Good Luck - Keep us posted.

message edited by Mike Newcomb

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November 8, 2018 at 02:20:48
I would have thought that any serial port would emulate an 8250.

Are you sure that your add-on works with DOS and is not just designed for Windows?

Have you checked that the serial ports are enabled in the BIOS?

Perhaps you could link us to the documentation for your add-on card, or list its manufacturer and model.

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November 8, 2018 at 09:35:29
Thanks to both of you, good advice. I'll keep you posted.

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