[comp.sys.ibm.pc] 16450 compatible with 8250 ?

john@wa3wbu.UUCP (John Gayman) (12/21/87)

     I recently installed a serial card in my 8 Mhz AT that contains a
8250 chip. I've since ordered the second serial port for the card and I
was sent a 16450 and associated chips. My question, is the 16450 plug
compatible with the 8250 ?  Also what are the pros and cons of using the
8250 in an AT ?  I know I've seen many serial cards advertised as either
"XT" or "AT" cards and the only difference appears to be the XT cards
usually use the 8250 and the AT cards the 16450. Thanks.

					John, WA3WBU


-- 
John Gayman, WA3WBU              |           UUCP: uunet!wa3wbu!john
1869 Valley Rd.                  |           ARPA: wa3wbu!john@uunet.UU.NET 
Marysville, PA 17053             |           Packet: WA3WBU @ AK3P 

ashok@softart.UUCP (Ashok C. Patel) (12/23/87)

> 
>      I recently installed a serial card in my 8 Mhz AT that contains a
> 8250 chip. I've since ordered the second serial port for the card and I
> was sent a 16450 and associated chips. My question, is the 16450 plug
> compatible with the 8250 ?  Also what are the pros and cons of using the
> 8250 in an AT ?  I know I've seen many serial cards advertised as either
> "XT" or "AT" cards and the only difference appears to be the XT cards
> usually use the 8250 and the AT cards the 16450. Thanks.

From what I have been told, the 16450 is a fast 8250.  That is, that it
is the chip that *must* be used in an AT style machine.  It also fixes
bugs in the original 8250 silicon (so I have been told...any confirms?).
The 8250 works fine in an XT style machine.

> 
> 					John, WA3WBU
> 
> 
> -- 
> John Gayman, WA3WBU              |           UUCP: uunet!wa3wbu!john
> 1869 Valley Rd.                  |           ARPA: wa3wbu!john@uunet.UU.NET 
> Marysville, PA 17053             |           Packet: WA3WBU @ AK3P 

-------------------------
Ashok C. Patel
Softart Microsystems Inc.

wnp@killer.UUCP (Wolf Paul) (12/25/87)

In article <31@softart.UUCP> ashok@softart.UUCP (Ashok C. Patel) writes:
>
>From what I have been told, the 16450 is a fast 8250.  That is, that it
>is the chip that *must* be used in an AT style machine.  It also fixes
>bugs in the original 8250 silicon (so I have been told...any confirms?).
>The 8250 works fine in an XT style machine.
>

It *must* be used in an AT style machine? For several months I used my old
XT-style multifunction card with two 8250-based serial ports on it in my 
10MHz DTK AT clone, running both DOS and Microport UNIX on it. It worked 
fine, and I only swapped it for an AT-style serial board because I needed
the clock function of the XT board for an XT clone I assembled for a friend.

Wolf Paul
ihnp4!killer!dcs!wnp

gu.morris@SCIENCE (Richard D. Morris) (01/21/88)

It turns out that the 16450 is a faster version of the 8250 with a number of
bugs in the 8250 fixed.  You should have no problems using the 16450 in place
of the 8250, if the software you are using doesn't rely on some of the bugginess
of the 8250.

The 8250 should not be used in IBM/AT and compatible machines because its cycle
times are too long for reliable operation at AT bus speeds.

You can obtain from National Semiconductor a comprehensive list of the
differences and bug fixes between the 8250 and 16450.

Hope this was of some help.

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