.            SID TUNER
.          John L Turner
.
.   This utility can play any SID music
file - 3-voice or 6-voice (if you have
the second chip) - while displaying
current values of many of the param-
eters and permitting you to change
settings and hear the results immedi-
ately. You do not need to change names
or extensions in order to play stereo
files.
.
Preparing Files for "Tuning"---
(Note - the first-time user might do
well to skip this section for now and
go on to "Step-by-Step Instructions)
.   Any SID file can be played in
either channel; but for serious tuning
it's best first to edit files in two
ways - (a) Repeats and (b) Vibrato
Settings.
(a) Endless Repeats. Select a section
pg
you want to work on; and insert 'HED 0'
.   (or possibly HED 2 or more)
before it and 'TAL' at the end. This
must be done at exactly the same point
on every voice. Then that section will
.   (or can be made to - read on)
play over and over while you fine tune
its sounds and get a print-out of all
the settings.
.   You can - yes *CAN* - have more
than one such section. Other players
would get permanently stuck in the HED
0 loop; but SID TUNER's "B" command
(see below) provides a way to break out
and move on. Also the 'S' command lets
you make any HED-loop act like a HED 0
loop and play over and over.
.   Your file can set parameters any
way you like (I like to rough in a few
before fine tuning) but it's best to
keep such settings outside of the HED-
TAL loops (at least for params you plan
to fine tune).
pg
(b) Vibrato Settings ---
.   Insert non-zero values of VDP and
VRT before the first HED-TAL loop. Do
this on every voice (unless you're sure
you won't want vibrato on that voice).
Setting VDP=1 and VRT=1 makes no aud-
ible  difference (to my old ears) but
gives you control of vibrato. SID TUNER
protects you against accidentally
losing control of vibrato - it just
won't let you set VDP or VRT to less
than one.
.
.      Step-by-Step Instructions
.   After loading the player module and
a block of sprite data the program asks
for information about the second SID
chip. Follow instrucions. Many people
need only press RETURN.
.   Then it asks for a filename. The
'$' under the cursor reminds you that
you can view a directory of all .mus
and .str files by just pressing RETURN.
pg
Or enter the name (without extension).
Then the full filenames of left & right
channel are checked separately - giving
you a chance to make changes if needed.
.   Now the files are loaded. The piece
starts to play and the screen fills up
with the first set of parameters -
those that can be different for each
voice. At the bottom of the screen are
reminders of some of the available com-
mands. One of them - '+' - moves you
back and forth between that screen and
the one which shows the all-voice par-
ameters. Both screens work the same.
.   Use cursor controls to move the
black cursor to the channel/voice/par-
ameter you want to change. (4-way wrap-
around saves time if you've got far to
go). Press RETURN. The cursor blinks
and a box opens to show the limits for
that parameter. Enter the value you
want to try and press RETURN again.
Your value takes effect.
pg
.   Other Available Commands---
'B' breaks out of a HED-TAL loop so the
     piece can proceed.
'S' if pressed while *any* HED-TAL loop
     is playing makes that loop repeat
     endlessly until 'B' is pressed.
'H' causes a condensed help screen to
     appear.
'P' causes a table of current values of
     all parameters to be printed out.
     First there's a pause to let you
     check the printer & (optionally)
     type a 'patch' label. Printing
     starts when you press RETURN.
'+' changes between the voice-specific
     parameters and the all-voice (or
     channel-specific) parameters.
'X' stops the music. You then have 3
     options - Re-start it (with all
     parameters re-set ... Print out
     latest parameters (last chance &
     nicer than printing during playing
     because printing murders tempo)...
pg
     Enter a new filename.
.
.               NOTES
VDP & VRT - If your SID file doesn't
     set these to non-zero values you
     won't be able to control vibrato.
     The sound won't change even though
     your values appear on the screen.
F-C & AUT - Changes in these filter
     controls may need some jiggling to
     become audible. Suggestion - set
     F-S=1. Then changes in F-C work.
     (This can be done from SID TUNER
     unlike VDP=1).
TEM - The program automatically enters
     tempo changes in both channels in
     an effort to preserve synchroniz-
     ation. But sync can very easily be
     lost - especially if the change is
     entered (by pressing RETURN) in
     the middle of a busy passage.
.
.   There are other problems with tempo
pg
too. Only certain values are allowed.
If you try to enter something else the
program approximates as best it can.
But your piece may use durations which
aren't supported in the tempo entered.
In that case synchronization will be
lost and the only solution will be to
press 'X' and start over - possibly
printing out your settings first.
Moral - leave tempo experiments to last
and don't experiment wildly if your
piece uses any durations shorter than
eighth notes.
.         -----------
Quick Reset - Pressing RETURN twice
is a quick way to enter zero (or 1 in
the case of params that don't allow
zero).
.       ************
   ** A note about TUNABLE. This is a
ready-to-tune 6-voice SID to play with.
Good old Frere Jacques (dormez-vous)
has been given a few parameters because
pg
otherwise I'd have gone nuts while de-
bugging. But you can change them in any
way you like. It will only play twice
unless you press 'S' (for "Stay"). When
satisfied with (or sick of) it press
'B' to move on to Big Ben's chimes so
you can play with RNG & TPS and maybe
a pinch of DTN or SNC. I was always too
lazy to experiment with those until
SID TUNER made it much easier.
             -*-*-*-*-*-
(NOTE - You can get a hard copy of this
file ätunerdocså with SPRINT or ULTRA)
.   Please send questions comments or
criticisms by E-Mail to JohnT58 or by
US Mail to J Turner/6060 South Airline/
Bloomington IN/47401.
.   I hope this pgm will be both useful
and fun !!    ----- John
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