Date: Mon, 17 Feb 1997 18:42:24 +0100 (MET)
From: Jan Hubicka <hubicka AT ta DOT jcu DOT cz>
To: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
cc: Ian Miller <itmiller AT dra DOT hmg DOT gb>, djgpp AT delorie DOT com
Subject: Re: Exact timming II
In-Reply-To: <Pine.SUN.3.91.970217153640.18258B-100000@is>
Message-ID: <Pine.LNX.3.91.970217184106.32365A-100000@tabor.ta.jcu.cz>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII

On Mon, 17 Feb 1997, Eli Zaretskii wrote:

> 
> On Mon, 17 Feb 1997, Jan Hubicka wrote:
> 
> > please can you send me separated uclock code? (I don't want to download
> > whole library sources and uncompress then to my 80MB dos partition)
> 
> Below.  Btw, you don't need to uncompress the entire lot to get a single 
thank you..
I was laso lazy to download it throught my 4800 baud line..
> source.  Just uncompress that single source and use it.  Anybody who's 
> serious about DJGPP development should IMHO have djlsr at his disposal, 
> if only to see what the docs forgot to mention.
I have sources at home at my 200MB disc..but not here because of lack
of space..(before djgpp division 80MB -> dos and 500MB -> linux was OK)

Honza
> 
> /* Copyright (C) 1996 DJ Delorie, see COPYING.DJ for details */
> /* Copyright (C) 1995 DJ Delorie, see COPYING.DJ for details */
> #include <time.h>
> #include <pc.h>
> #include <libc/farptrgs.h>
> #include <go32.h>
> #include <libc/bss.h>
> 
> static int uclock_bss = -1;
> 
> /* tics = about 18.2 * 65536 (1,192,755)
> 
>    actually, it's   0x1800b0 tics/day (FAQ)
>                   / 24*60*60 sec/day
>                   * 65536 utics/tic
> 		  = 1,193,180 utics/sec */
> 
> uclock_t
> uclock(void)
> {
>   static uclock_t base = 0;
>   static unsigned long last_tics = 0;
>   unsigned char lsb, msb;
>   unsigned long tics, otics;
>   uclock_t rv;
> 
>   if (uclock_bss != __bss_count)
>   {
>     /* switch the timer to mode 2 (rate generator) */
>     /* rather than mode 3 (square wave), which doesn't count linearly. */
> 
>     outportb(0x43, 0x34);
>     outportb(0x40, 0xff);
>     outportb(0x40, 0xff);
> 
>     base = 0;
>     last_tics = 0;
>     uclock_bss = __bss_count;
>   }
> 
>   /* Make sure the numbers we get are consistent */
>   do {
>     otics = _farpeekl(_dos_ds, 0x46c);
>     outportb(0x43, 0x00);
>     lsb = inportb(0x40);
>     msb = inportb(0x40);
>     tics = _farpeekl(_dos_ds, 0x46c);
>   } while (otics != tics);
> 
>   /* calculate absolute time */
>   msb ^= 0xff;
>   lsb ^= 0xff;
>   rv = ((uclock_t)tics << 16) | (msb << 8) | lsb;
> 
>   if (base == 0L)
>     base = rv;
> 
>   if (last_tics > tics) /* midnight happened */
>     base -= 0x1800b00000LL;
> 
>   last_tics = tics;
> 
>   /* return relative time */
>   return rv - base;
> }
> 

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