Dec 072017
Three control programs for the NS16550 UART.
File UARTOOLS.ZIP from The Programmer’s Corner in
Category Communications
Three control programs for the NS16550 UART.
File Name File Size Zip Size Zip Type
FIFOFF.COM 293 277 deflated
FIFON.COM 275 264 deflated
FIFOSTAT.COM 304 274 deflated
READ.ME 2248 1177 deflated

Download File UARTOOLS.ZIP Here

Contents of the READ.ME file


Milliways! Software Systems.
P.O. Box 26444
Greenville, SC 29616
(803) 297-3236

FIFON.COM - Turn on FIFO buffer in NS16550AN UART.
FIFOFF.COM - Turn off FIFO buffer.
FIFOSTAT.COM - Report present FIFO status w/out changing it.

All commands can take a list of COM ports, e.g.


will report the status of all 4 COM ports. Default is COM1. COM3 and
COM4 use the 'standard' 03E8h and 02E8h addresses. FIFON and FIFOFF
will both verify the existance of a 16550AN, while FIFOSTAT, which
never changes anything, will probably report FIFO off for other UART
types (which is technically correct.)

UARTTOOLS! developed out of a desparate need. We all know how the
16550AN is our saviour for flow control problems, particularly with high
speed modems, but I discovered that many applications could not deal
with the FIFO buffer being left on. My hypothesis is that some comm
packages are written expecting a interrupt with every incoming
character. The FIFO buffer on the 16550AN can hold 16 bytes before
generating an interrupt. Therefore, the 'dumb' comm program picks up
only one character at interrupt time rather than all 16. The UART can't
accept any more so it waits, the 'dumb' comm program is waiting for the
next interrupt, and we end up reaching for the reset button. Now, what
are the 'dumb' comm programs? Well, I've found that BIXLink, JLBlink,
and TapCIS all die a horrible death when the FIFO is activated. I'm
sure there are many more.

Now for the legal stuff...

UARTTOOLS! are fully protected under U.S copyright laws. You are free to
use them, share them, and upload them to your favourite BBSs. You are
not allowed to charge for them, distribute modified copies, hack this
documentation, or otherwise talk dirty to them. While I have tested
them to the best of my ability, I do not make any guarentees as to their
effectiveness or reliability. (Don't sue me)

ASM source code for UARTTOOLS! is available for $5.00 mailed to the
above address. Comments are encouraged. Enjoy!


Copyright 1990 Milliways! Software Systems. All Rights Reserved.

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