NetNews Usenet Archive 1993 #1/NN_1993_1.iso/spool/comp/dcom/modems/19277

Text File | 1993-01-11 | 3.2 KB | 73 lines

Path: sparky!uunet!valinor.mythical.com!n5ial!jim
From: [e-mail] (Jim Graham)
Newsgroups: comp.dcom.modems
Subject: Can I upgrade a 16450 uart to a 16550a?
Message-ID: <[e-mail]>
Date: Sun, 10 Jan 93 09:42:37 GMT
References: <[e-mail]>
Distribution: world
Organization: Me? Organized? Hah! :-)
Lines: 61

In article <[e-mail]> [e-mail] writes:

> [I wrote]:

>> In article <[e-mail]> [e-mail] writes:
>
>>> I was almost sure Dell would have put a good uart in the
>>> machine, but it turns out it's only a 16450.
>>>
>>> Is it possible to upgrade the 16450 to a 16550a?
>
>> yes.  they are pin-compatible, provided that you replace it with the
>> same package...e.g., replace DIP (16550AN or 16550AFN) with DIP, etc.

> But in the case of the Dell 325D, the "16450" isn't a separate chip;
> it's part of VLSI which is soldered in place. In such cases you have
> to add a card with the new chips on it.

if that's the case, you're right.  however, the original post said that
the chip in question is a 16450, not a 16450 clone on a multi-port card.
that's what I responded to.

> Sorry, but the ignorance is on your side. The Dell 325D does in fact
> have a VLSI. I would say the trouble with the person at Dell was they
> assumed you were computer literate :-)

computer literate?  let's see, the original poster says that the serial
port has a 16450 UART in it, and wants to know if it can be replaced
with a 16550.  notice that he doesn't say the chip is a clone of a
16450, along with a bunch of other stuff rolled in --- he says it's a
16450, period.  if you look at a chip that's labelled xx16450 (where
xx are the vendor's initials), well, it seems pretty straightforward to
me that it's somebody's 16450....

based on that information (which appears to have been incorrect to begin
with), my statements were correct --- it can be directly replaced with a
16550.  of course, that assumes that the app-notes and specs from
National Semiconductor are correct.  :-)  and it also assumes that I
wasn't dreaming when I replaced a few 16450s with 16550s a while back.

btw, just as a bit of nit-picking, replacing one chip with another
isn't so much a question of being computer literate as it is a matter
of being HARDWARE literate.  just so happens that some of us are both
(after all, when designing and/or interfacing with the hardware, it's
often hard these days to draw the line between where the hardware stops
and the software begins).  but this question (``Is it possible to
upgrade the 16450 to a 16550a?'') is purely a hardware question, not
a software question.

gotta run.  sooner or later, I'm going to find time to get some sleep
(maybe...if I don't lose the hard drive's data again....).
   --jim

--
#include <std_disclaimer.h>                                 73 DE N5IAL (/4)
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