Tuner 2.1
Reference-tone generator for tuning a musical instrument
Freeware, (c) 1995  Martin Pergler

TUNER is an MS-DOS program that will emit a reference tone through your
PC speaker to help you check the tuning of a musical instrument.
You can specify the base tuning frequency (default A=440.0Hz),
the note to emit (equal temperament only) and an adjustment in
cents (100 cents=1 semitone).  TUNER _cannot_ judge the pitch _you_ are
playing on your instrument.

By default, you control TUNER from the keyboard:  the menu should
be self-explanatory.  You can also specify the desired parameters
from the command line.  Example
  TUNER F#4 442.0 +7.5
	play F# in octave 4 (same octave as A440)
	    using A442 tuning
		  adjusted sharper by 7.5 cents.  Could use - for flatter.

Limitations
-----------
TUNER was written out of necessity in 3 hours with antiquated tools
(Turbo C 2.0 (!)) --- I was on a trip, got a chance to
try some new instruments.  I had my notebook computer along, but no
electronic tuner.  The user interface is not snazzy, and
the sound quality can be scratchy, especially while multitasking under
Windows.  The included PIF file runs TUNER in exclusive mode, which
eliminates some clicks and snaffles.

A much fancier program could be written to use multimedia features on
newer computers.  Perhaps, using sampling, such a program could even judge
played pitches, like most electronic tuners do.  I'll leave that to
someone who has done some programming in the past few years.

The standard TurboC 2.0 sound() function only accepts whole-number
frequencies, so I had to hack together a replacement that can
play frequencies in a fractional number of Hz.  I think it should
work on all computers, but no guarantees.

Over the years I have not come across any computer whose speaker would
sound distinguishably off-pitch.  But who knows.

I hope this is of use.  Please email me with any comments or suggestions.

Martin Pergler          pergler@math.uchicago.edu
Math grad student, University of Chicago
Clarinettist, recorder player, and singer (amateur)

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