5 Channel C64 sids..

[Feekzoid]

... I did not think were actually possible - I knew that it was possible to to some clever tricks of your were playing back sample loops only etc - but not 2 channels of independant sample playback!

I belatedly noticed that due to C64 compliancy that sids featuring sample data now had the _PSID duplicate - which I used as a search to see how many HVsids there were with samples - 604 I think it was, so naturally I plowed through some of the ones I didnt know - and came across (amongst others) Linko_PSID.sid

Bloody hell!

Makes me feel like a fool for my "5" channel trickery tune that I did, I can tell you!

How did they do this?

[Pex `Mahoney` Tufvesson]

I did it too, in my glory days... (playing two samples at a time, I mean - I have not listened to the PSID you refer to).

loop:
lda ($30),y ;load sample(y) from the first sound
adc ($32),y ;add it with sample(y) from the second sound
sta $d418 ;change the volume, which will bring the sound to the output
iny
bne loop

...that will play both samples at the same time. Ok, there's a lot more code if you want it interrupt-driven, etc, but the theory is the same.

It's just that previous emulation of SID tunes never cared for any other sampleplaying method than the "normal" one. Precalculated sound can also be used.

[Feekzoid]

Cool. shame I never came across any editors to do this - or if I thought it would actually possible I might have modified the Digi-Organiser code to allow it - but I would still have needed an editor, and that was beyond my coding ability!

A sid tune that still seems to be missing in the HVsid collection that I've often looked for is the title theme from a demo by the group OFFENCE! (or that may have been the demo) The demo had a precalculated OFF! logo semispinning. Of more note was the SID tune with samples with a very clever sliding panflute type instrument amongst others.

[Waz]

... I did not think were actually possible - I knew that it was possible to to some clever tricks of your were playing back sample loops only etc - but not 2 channels of independant sample playback!

Sure is. Try some of Mark Wilson's if you don't believe me, especially Xenomorph and the intro tune to Volfied, and also the intro to Reyn Ouwehand's Arena:

/Wilson_Mark/Volfied.sid #1
/Wilson_Mark/Xenomorph.sid
/Ouwehand_Reyn/Arena.sid #1

Incidentally, you're best off playing the non PSID version of a sample tune if it exists (they haven't all been done yet btw). Simple reason is that the old _PSID versions were ripped for older SID emulators that couldn't play back real C64 samples properly, and made use instead of the extended PSID digi registers to play the samples. The non-PSID versions use the real C64 routines to play it back properly and also will play on a real C64 too (I should know, I re-did almost all of yours, Feekzoid! :)

I did it too, in my glory days... (playing two samples at a time, I mean - I have not listened to the PSID you refer to).

It's just that previous emulation of SID tunes never cared for any other sampleplaying method than the "normal" one. Precalculated sound can also be used.

I recall you doing a couple of ones like that, Mahoney! Actually, the old Sidplay1-based emulation introduced something back in 1998 which was designed to play back 2-channel digi plus 3 channel SID voices, and that was the introduction to an extension to the PSID Extended SID registers with a second channel settings which allowed you to play them a bit better. While this broke compatibility with Amiga PlaySID, it was progress.

Basically, with the old PSID method, the last bytes set were $D41D (to play sample 1) and $D51D (to play sample 2). A full set of those bytes are on the Sidplay page here:

http://www.geocities.com/SiliconValley/ ... 7/sidplay/

Go to the docs section, then the ripping link, then the converting sample players link.

For channel 2, replace $D4 with $D5 accordingly.

[Waz]

A sid tune that still seems to be missing in the HVsid collection that I've often looked for is the title theme from a demo by the group OFFENCE. The demo had a precalculated OFF! logo semispinning. Of more note was the SID tune with samples with a very clever sliding panflute type instrument amongst others.

I know the one you mean! It's from the Offence demo Emotional Breakdown. The tunes I think you need are here (and the digi tune is in the part with the spinning off logo too!):

tune 1 - /MozIcArt/Tjelta_Geir/Orcanic.sid (intro tune)
tune 2 - /MozIcArt/Tjelta_Geir/Orchestra.sid (digi tune with spinning off logo)
tune 3 - /MozIcArt/Tjelta_Geir/Geir_Tjelta-12.sid (offence logo at bottom)
tune 4 - /MozIcArt/Tjelta_Geir/Flamboyant.sid (big Emotional Breakdown writing in dots)
tune 5 - /MozIcArt/Tjelta_Geir/Geir_Tjelta-02.sid (Offence logo with palm tree in the N and C)
tune 6 - /VARIOUS/G-L/Harmony_Productions/Hurz.sid (scroller through raster splits)
tune 7 - /VARIOUS/G-L/Harmony_Productions/Die_Qualle.sid (turn disk)
tune 8 - /VARIOUS/G-L/Harmony_Productions/Little_Tear.sid (Amiga Inspiration part)
tune 9 - /MozIcArt/Lindanger_Trond/Two_Divided_by_Zero.sid (vertical rasterbars with off! logo)
tune 10 - /MozIcArt/Tjelta_Geir/Brain_Artifice.sid #11 (naked fairy chick, last part)
note tune - /VARIOUS/G-L/Harmony_Productions/Wot_Is_Love.sid

Hope that helps. And next time, please use the SID Hunt at http://lala.c64.org/ - that's what it's there for.