Denial

One of the most annoying things about VIC 20 is that the music all too often plays horribly out of tune. This program improves the frequency accuracy of square voices 1-3 from 7 bits (0-127) to 10 bits (0-1023).

Fantastic!

Download: http://www.cncd.fi/aeeben/download/10-bit-ofr.zip

To init: jsr $0340 or sys832
To stop: lda #$40, sta $911e or poke37150,64

Set VIA #1 timer 1 rate ($9114/$9115) to adjust sound quality. Default is $0580.

Set sound quality in basic: poke37141,x (x=5 default, x=0 highest, usable low quality range up to x=30)

Default value is usually quite fine unless you play very high notes.

$f8/248 Voice 1 enable (bit 7) & frequency high 7 bits (bits 6-0) (same as $900a/36874)
$f9/249 Voice 2 -"- (same as $900b/36875)
$fa/250 Voice 3 -"- (same as $900c/36876)

$fb/251 Voice 1 frequency low 3 bits (range 0-7)
$fc/252 Voice 2 -"-
$fd/253 Voice 3 -"-

Invalid values (>7) in $fb-$fd will cause inaccurate sound output.


The note and Hz values in frequency tables pal-freqtable.png and ntsc-freqtable.png are calculated for Voice 1, the lowest voice.

Voice 2 plays an octave higher (Hz * 2)
Voice 3 plays two octaves higher (Hz * 4)

pal-freqtable.bin / ntsc-freqtable.bin format:
The first 72 ($48) bytes are high bytes for writing to $f8-$fa
The next 72 bytes are low 3 bit values for $fb-$fd


LOAD"10-BIT-OFR.PRG",8,1

SEARCHING FOR 10-BIT-OFR.PRG
LOADING
READY.
NEW

READY.
SYS832:POKE36878,15:REM Init and set volume

POKE248,215:POKE251,5:REM Play A-1 / 110Hz on ch 1 (36874)
POKE249,215:POKE252,5:REM Play A-2 / 220Hz on ch 2 (36875)
POKE250,215:POKE253,5:REM Play A-3 / 440Hz on ch 3 (36876)

POKE248,0:POKE249,0:POKE250,0:REM Stop all voices
POKE36877,130:REM You can use noise channel normally

POKE37141,0 - Set highest quality (great for high notes, but slows down basic)
POKE37141,5 - Set default quality (good quality/cpu load balance)
POKE37150,64 - Disable timer NMI, sys832 to start again


Basic Loader:

1 fora=832to915:readb:pokea,b:next
100 data169,99,141,24,3,169,3,141,25,3,169,128,141,20,145,133,254,162,5,142,21,145,169
101 data0,149,248,202,16,251,169,192,141,30,145,96,72,152,72,138,72,6,254,144,2,230,254
102 data162,2,180,251,185,140,3,180,248,37,254,240,1,200,152,157,10,144,202,16,237,104
103 data170,104,168,104,44,20,145,64,0,128,136,146,170,218,238,254


Frequency Tables:

aeb wrote: Fantastic!

Absolutely! And genius!

Am wondering what games will look like in 2020!

Interesting approach. Special +1 for posting source code. Haven't tried it on hw, how good quality can you get?

I can't wait to find the time to rest it out.

Hello .
I tried to adapt the song “sonata c major”
with 10bit program.
I like writing basic music with the Vic20.
Unpacked the .zip file for
play with winvice or true vic20 and drive or Sd2iec
Armando .

You're using it wrong... Your program only sets the high 7 bits of frequency, so there's no difference from normal VIC frequency resolution.

You need to include also the low 3 bits in the data for each note - the small values 0-7 in the frequency table at start of this thread - and write them to the other zero page register. Now you're writing the same 8-bit value to both registers, on line 230, which doesn't make any sense.

- Registers S2,S3 defined in 130 should be 248,251 or 249,252 or 250,253 depending on the voice you want to use
- Line 210: READP,L,D
- 230 POKES2,P:POKES3,L
- Edit all data statements on lines 300-1730 and add the low 3 bits (0-7) for each note
300 DATA 225,8,231,4,235,4,... =>
300 DATA 225,4,8,231,5,4,235,3,4,... etc

armypavarmy wrote:Hello .
I tried to adapt the song “sonata c major”
with 10bit program.
I like writing basic music with the Vic20.
Unpacked the .zip file for
play with winvice or true vic20 and drive or Sd2iec
Armando .

10bit-sonata.zip

10 bit test
Hello
please check this music
that I wrote to try
your corrections.
and tell me if it's okay.
For the songs already written I have to
change the value of the note too
that in your table is different.
from those used in 8-bit for Pal
thanks greetings Armando

Very nice!

armypavarmy wrote:10 bit test
Hello
please check this music
that I wrote to try
your corrections.
and tell me if it's okay.
For the songs already written I have to
change the value of the note too
that in your table is different.
from those used in 8-bit for Pal
thanks greetings Armando

10bit-pr.prg.zip

How does this work exactly? I.e. the theory behind it as opposed to how to use it...

Hello
composed song using
the 10bit oscillator program
new simple Christmas song
Best wishes to all.
Armando

Hello
composed a new song using
the 10bit oscillator program
Name “ Let Is Snow “

It toggles between the high byte and the high byte + 1, depending on the low byte.
The data table determines when to add 1 to the high byte, on an eight bit cycle.

EDIT Ah, I didn't notice there was already source code in the ZIP!

Hello
two new music
rewritten by me at 10Bit.
Sonata in D major
Turkish march
Armando

Hello
one new music
rewritten by me at 10Bit.
Somethin’ Stupid
Armando

Two new songs
10bit piano Vic 20two new songs
the first of Anonymous
the second traditional Irish song
Armando