Date: Sat, 20 Dec 1997 10:34:51 -0800 (PST)
Message-Id: <199712201834.KAA17115@adit.ap.net>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
To: Adam Young <ayoung AT ksu DOT edu>, djgpp AT delorie DOT com
From: Nate Eldredge <eldredge AT ap DOT net>
Subject: Re: Parallel Port and printf
Precedence: bulk

At 11:16  12/19/1997 -0600, Adam Young wrote:
>Hello,
>
>I am developing a program that uses the parallel
>port to read a 4-bit BCD number and return the
>decimal value. I am accomplishing this by constantly
>scanning the port and checking for the strobe (DV)
>to go high. Once it goes high, the 4-bit word is
>sent to "conv" to be converted to the corresponding
>decimal value and printed to the screen. This is the 
>problem. The "printf" marked with the ???? is needed
>for the numbers to be printed out "real time". If
>I do not have the "printf ("\n");" statement, the
>program only writes to the screen AFTER I hit control-c
>to stop the program. I am using DJGPP and RHIDE to
>develop this program.
>
>What I want is to print the data to the screen (and,
>later to be logged in a file) in a row (ie. "123456")
>instead of on a new line each time. I am sure this 
>is not a problem with DJGPP or RHIDE but a simple 
>"error" that I am making. Any help is appreciated.
>Thanks in advance!
This happens because the stdio stream is line-buffered. The simplest way to
fix it is probably to replace your `printf("\n");' with `fflush(stdout);'.
Also see FAQ section 9.4.

Nate Eldredge
eldredge AT ap DOT net