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No-XS
Registered: Mar 2002
Posts: 79 |
Detect instrument being played (goattracker)
I have a goattracker sidtune and for a demoscreen I want some visual to happen when a snaresound is being played.
Because I'm not the best coder there is, I cannot find any way to do this or find a tutorial or reference to it. From years ago I remember doing it for other sids from another editor.
Is there an easy way to detect a certain instrument, say on channel1 ? |
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Jammer
Registered: Nov 2002
Posts: 1335 |
One way is just to monitor player area and dump it to screen memory. Take a look, which areas are changing, calculate which place it is et voila ;) |
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chatGPZ
Registered: Dec 2001
Posts: 11386 |
what i would do.... look at the player source and locate a suitable variable. tnat gives you an idea in what area of the binary it will be located. then hack up a small program that plays the tune and copies the first few pages of the player (where the variables are located) to screen. stare at the screen and locate the exact position of the byte that changes to whatever value when the instrument is played. (i think there are even tools for this, "music watcher" or something, dont recall) |
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Oswald
Registered: Apr 2002
Posts: 5094 |
It's Rythm V1.2
this tool helps in finding the byte in memory. serves me since mid 90's for this purpose.
you just look for the color changes on screen as the music plays basically, then you can pick some favourite spots, and monitor them.
shows you both address and value. |
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No-XS
Registered: Mar 2002
Posts: 79 |
Cool! Thanks! |
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TheRyk
Registered: Mar 2009
Posts: 2244 |
I could not find the tool I originally wanted to recommend you (?OUT OF MEMORY), but while searching I discovered this one:
SidInspector
Looks pretty much like what yer looking for. |
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daison
Registered: May 2005
Posts: 90 |
We tried both It's Rhythm and SidInspector.
It's Rhythm really worked out well for us.
Despite some bugs (may crash when moving the cursor around) it's pretty insightful what is happening wear exactly.
SidInspector seemed to have issues with sids above $2000? Apart from that it's a somewhat less userfriendly in every way. But tnx anyway. It was fun playing around with these tools!
The result:
Outline 2015 Invitation |
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Oswald
Registered: Apr 2002
Posts: 5094 |
glad its ryth worked out. was totally stable for me always, probably this player interferes with some zp var they both use. |
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Domspitze
Registered: Oct 2013
Posts: 2 |
Sorry for this stupid question. But how can I use another sid in sidinspector? |
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TheRyk
Registered: Mar 2009
Posts: 2244 |
It only works with SIDs located at $1000.
Summary sez:
"load another standard SID to $1000 and restart SidInspector with SYS 2064 ($0810)"
http://csdb.dk/release/?id=112199&show=summary#summary
so after loading and RUNning SidInspector, soft-reset, then make sure your tune is at $1000 (without .SID header of course) and then either load it in direct mode or in monitor. |
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Klegg
Registered: Feb 2006
Posts: 16 |
You could also use timing marks in Goattracker. From the manual:
"Command DXY: Set mastervolume to Y, if X is $0. If X is not $0, value XY copied to the timing mark location, which is playeraddress+$3F." |
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No-XS
Registered: Mar 2002
Posts: 79 |
Quote: You could also use timing marks in Goattracker. From the manual:
"Command DXY: Set mastervolume to Y, if X is $0. If X is not $0, value XY copied to the timing mark location, which is playeraddress+$3F."
Ah! I thought so already that something similar would have been included, but it's not the first time that I don't really understand what the manual speaks of until someone explains it to me! Some other things in goattracker happened when making the song that I couldn't explain, but I worked around it. Maybe I should start a new topic on that, or ask Cadaver directly. |
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Flotsam
Registered: Jan 2004
Posts: 84 |
I know this thread is almost as old as an average C64 scener, but since Google brought me here and possibly others too when searching for info on detecting the instrument playing in a GoatTracker song, I'll leave a tiny piece of code here that I wrote because I felt uncomfortable using It's Rhythm. It searches for a signature that tells the start address of the significant data. The same data structure repeats for each channel as follows (from Cadaver in another thread), starting from the address found:
mt_chnsongnum:
.BYTE (0)
mt_chnpattnum:
.BYTE (0)
mt_chntempo:
.BYTE (0)
mt_chncounter:
.BYTE (0)
mt_chnnote:
.BYTE (0)
mt_chninstr:
.BYTE (1)
mt_chngate:
.BYTE ($fe)
THE CODE (KickAssembler format):
---------
BeatDetector:
ldy #0
BDloop:
lda ($fa),y
cmp BDdata,y
bne BDnext
iny
cpy #21
bne BDloop
BDfound:
rts
BDnext:
inc $fa
bne BDloop
inc $fb
bne BDloop
brk /*we're fucked*/
BDdata:
.byte 0,0,0,0,0,1,$fe
.byte 1,0,0,0,0,1,$fe
.byte 2,0,0,0,0,1,$fe
------------
Call it by initing $fa with start address of the song:
lda #<$1000
sta $fa
lda #>$1000
sta $fb
jsr BeatDetector
/*$fa-$fb now holds the starting address*/
For a release version you'd of course skip the search, but on production stage it's nice to have an automatic detection for changing versions of the song. Also, it's in no way dynamic. Doesn't account for using less than 3 channels etc. Life is tough. |
