Commodore 64 vs Atari 800 Xl

[TMR]

This was posted over in the A8 forum, but what a great Pokey conversion! Awesome sawtooth at 0:27.

 

Yeah, saw (okay, heard) it earlier... got to love the Wings of Death soundtrack. =-)

[potatohead]

This was posted over in the A8 forum, but what a great Pokey conversion! Awesome sawtooth at 0:27.

 

 

Pokey's not so bad. Too bad no one figured out how to do that sooner.

 

Hell, yes! That's one of the very best, I've heard.

[PeteD]

This was posted over in the A8 forum, but what a great Pokey conversion! Awesome sawtooth at 0:27.

 

 

Pokey's not so bad. Too bad no one figured out how to do that sooner.

 

Yeah, saw that earlier, that's what I now expect POKEY to sound like. I still hear out of tune bits but they aren't making me cringe, more just go "yeah, they're still there". Saw IS pretty good for POKEY

[potatohead]

This was posted over in the A8 forum, but what a great Pokey conversion! Awesome sawtooth at 0:27.

 

 

Pokey's not so bad. Too bad no one figured out how to do that sooner.

 

Yeah, saw that earlier, that's what I now expect POKEY to sound like. I still hear out of tune bits but they aren't making me cringe, more just go "yeah, they're still there". Saw IS pretty good for POKEY

 

There is an art to hiding out of tune, and that one balances it all very well.

[+SpiceWare]

This was posted over in the A8 forum, but what a great Pokey conversion! Awesome sawtooth at 0:27.

 

 

Pokey's not so bad. Too bad no one figured out how to do that sooner.

That's impressive.

[TMR]

So, since we're on the subject... anyone want to tell PeteD how to do the complex stuff so he can write a music driver around it? =-)

 

Despite having a HVSC folder to myself, i'm about as musical as a jackhammer - i can tell when something is off but not why to the point where i can do something about it. i've done my own sound effect drivers (i've got a prototype for the A8 in my current project that works a little like the SEUCK one on the C64) but if memory serves the only music driver i've ever written was for the Commodore PET with sound hack hardware!

[PeteD]

So, since we're on the subject... anyone want to tell PeteD how to do the complex stuff so he can write a music driver around it? =-)

 

Despite having a HVSC folder to myself, i'm about as musical as a jackhammer - i can tell when something is off but not why to the point where i can do something about it. i've done my own sound effect drivers (i've got a prototype for the A8 in my current project that works a little like the SEUCK one on the C64) but if memory serves the only music driver i've ever written was for the Commodore PET with sound hack hardware!

 

Yes, any example code, snippets of info etc would be handy I've done the basic player that does bugger all atm other than play patterns. It needs sounds and it may as well have all the newly discovered stuff I've got a bit of it sussed but better that I make sure and get any other bits and bobs anyone has.

 

No rush cuz I've got mountains of other stuff to do but just PM stuff to me whenever anyone finds anything out. Ta

[ceti331]

serious question.

I gather the C64 palette involved some compromises r.e. shared/flipped UV values

 

Does anyone think an improved 'universal 16color palette' would have been possible with benefit of hindsight (looking back at CPC464 & ST/Amiga games I guess..)

the only glaring change i'd make is to tweak the slightly sickly bright yellow

 

copying the palette from chaos-engine would probably not be universal enough IMO, excellent as it was.

Edited May 10, 2010 by ceti331

[+remowilliams]

Hell, yes! That's one of the very best, I've heard.

Yes, that is some sweet POKEY sound right there.

[Bryan]

Yeah, saw that earlier, that's what I now expect POKEY to sound like. I still hear out of tune bits but they aren't making me cringe, more just go "yeah, they're still there". Saw IS pretty good for POKEY

 

I hear it mostly in the poly-bass. I've only experimented with tuning square waves, but I wonder how it would work for the poly sounds.

 

There are three polynomial counters that allow four different pattern lengths (4,5,9,17 bit) and these are shared and sub-sampled by the 4 voices. With the shorter polys it's possible (and quite easy) to pick divisors that match the length of a simple repeating pattern within the sequence. When these divisor values are selected the sound may be different (or silent) depending on the alignment of the register write with the poly counter. I found that some of the settings create desirable sounds if they can be reliably triggered. One way I found is to use STIMER and/or quick SKCTL resets to put the code into alignment with the channels.

 

It's all so tricky, and this is the stuff that drives emulator authors crazy.

Edited May 10, 2010 by Bryan

[Barnacle boy]

serious question.

I gather the C64 palette involved some compromises r.e. shared/flipped UV values

 

Does anyone think an improved 'universal 16color palette' would have been possible with benefit of hindsight (looking back at CPC464 & ST/Amiga games I guess..)

the only glaring change i'd make is to tweak the slightly sickly bright yellow

 

copying the palette from chaos-engine would probably not be universal enough IMO, excellent as it was.

 

There was a very interesting thread on this subject at wayofthepixel.net

 

http://www.wayofthepixel.net/pixelation/index.php?topic=4306.0

 

The c64 palette actually compares quite favourably. Bear in mind though that in that thread they're generally treating the palette as having completely free colour placement with no restrictions. When designing a palette with placement restrictions in mind, smooth ramps might be less of a priority.

 

For use in games with c64-like restrictions, I feel that version 1 of the c64 palette was best, back when the colours were grouped into 3 different luminance ranges (5 if you include black and white) rather than the later 7 luminances (9 with b & w). With the old palette you basically had a range of dark colours, mid colours, and bright colours, which worked well for 3 colour sprites/tiles. However the newer palette is better for pictures - the extra luminance levels allowing for smoother gradations in tone.

[potatohead]

That's an excellent thread. Thanks for linking it.

[ANTIQ]

Yes, any example code, snippets of info etc would be handy I've done the basic player that does bugger all atm other than play patterns. It needs sounds and it may as well have all the newly discovered stuff I've got a bit of it sussed but better that I make sure and get any other bits and bobs anyone has.

 

I assume it's going to be a hardware waves and volume envelopes thing?

[DimensionX]

DX!

 

Help, why doesn't this work?

 

10 PRINT "HELLO WORLD!";

20 GOTO 1

 

 

Aaron

 

Want to have it that way?

 

Just bring it on.

 

I will really enjoy this.

 

 

You really are very stupid. Are you dizzy on Lemonade or something?

 

correct my code PLEASE!

 

show me you are not.

 

Aaron

 

And why can't you correct your code yourself?

[DimensionX]

Pokey archive is the right place for listening and to download pokey music.

http://asma.atari.org/

 

Greyscales tunes sound very good.

Edited May 10, 2010 by DimensionX

[DimensionX]

serious question.

I gather the C64 palette involved some compromises r.e. shared/flipped UV values

 

Does anyone think an improved 'universal 16color palette' would have been possible with benefit of hindsight (looking back at CPC464 & ST/Amiga games I guess..)

the only glaring change i'd make is to tweak the slightly sickly bright yellow

 

copying the palette from chaos-engine would probably not be universal enough IMO, excellent as it was.

 

There was a very interesting thread on this subject at wayofthepixel.net

 

http://www.wayofthepixel.net/pixelation/index.php?topic=4306.0

 

The c64 palette actually compares quite favourably. Bear in mind though that in that thread they're generally treating the palette as having completely free colour placement with no restrictions. When designing a palette with placement restrictions in mind, smooth ramps might be less of a priority.

 

For use in games with c64-like restrictions, I feel that version 1 of the c64 palette was best, back when the colours were grouped into 3 different luminance ranges (5 if you include black and white) rather than the later 7 luminances (9 with b & w). With the old palette you basically had a range of dark colours, mid colours, and bright colours, which worked well for 3 colour sprites/tiles. However the newer palette is better for pictures - the extra luminance levels allowing for smoother gradations in tone.

 

Thanks for a good link, that reminded me of what someone here said about C64's palette.

 

Interesting reading.

Edited May 10, 2010 by DimensionX

[TMR]

Thanks for a good link, that reminded me of what someone here said about C64's palette.

 

It reflects what most people in this thread said about the C64 palette yes, that it's got concessions because it was essentially built from a need to keep the silicon overheads down but is, in the long run and probably more through luck than judgement, very fit for the job in hand - after all, they wouldn't be spending all that effort analysing it or going as far as using variations for art on newer hardware if they didn't think so. They also talk about techniques such as dithering and using "pure grays [as a] bridge other hues" (which is something 8-bit artists do a lot of rather than using straight gradients and is evident in at least some of Mark Coleman's work) in a positive light and i can only think of one person in this thread who'd disagree with those points...

Edited May 10, 2010 by TMR

[DimensionX]

Thanks for a good link, that reminded me of what someone here said about C64's palette.

 

It reflects what most people in this thread said about the C64 palette yes, that it's got concessions because it was essentially built from a need to keep the silicon overheads down but is, in the long run and probably more through luck than judgement, very fit for the job in hand - after all, they wouldn't be spending all that effort analysing it or going as far as using variations for art on newer hardware if they didn't think so. They also talk about techniques such as dithering and using "pure grays [as a] bridge other hues" (which is something 8-bit artists do a lot of rather than using straight gradients and is evident in at least some of Mark Coleman's work) in a positive light and i can only think of one person in this thread who'd disagree with those points...

 

Some interesting reading. I didn't even knew that it was different versions of the C64 palette.

[PeteD]

Yeah, saw that earlier, that's what I now expect POKEY to sound like. I still hear out of tune bits but they aren't making me cringe, more just go "yeah, they're still there". Saw IS pretty good for POKEY

 

I hear it mostly in the poly-bass. I've only experimented with tuning square waves, but I wonder how it would work for the poly sounds.

 

There are three polynomial counters that allow four different pattern lengths (4,5,9,17 bit) and these are shared and sub-sampled by the 4 voices. With the shorter polys it's possible (and quite easy) to pick divisors that match the length of a simple repeating pattern within the sequence. When these divisor values are selected the sound may be different (or silent) depending on the alignment of the register write with the poly counter. I found that some of the settings create desirable sounds if they can be reliably triggered. One way I found is to use STIMER and/or quick SKCTL resets to put the code into alignment with the channels.

 

It's all so tricky, and this is the stuff that drives emulator authors crazy.

 

Yeah, one of the plans was to maybe write a new POKEY emulation too but I think it might be too reliant on things from the rest of the system that it'll be best to maybe simulate some of it for the PC editor (don't want to end up writing a new A8 emu) OR only do a native editor OR persuade someone like Phareon to keep updating Altirra whenever knew stuff is found.

[TMR]

Some interesting reading. I didn't even knew that it was different versions of the C64 palette.

 

The same is true of a lot of 8-bits - as you noted previously, the A8 changes it's colours depending on if it's CTIA- or GTIA-based (going NTSC to PAL or vice versa changes the palette as well and that's the same for all the Commodore machines if memory serves) and the Spectrum varies from model to model to the point where a minority of machines even differentiate between black and bright black - Spectrum colours also change intensity slightly depending on if they're used for set or unset pixels apparently, there's a CSSCGC entry from 2008 called Escape from Niburon Prime where the on-screen maze relies on that differentiation, rendering it invisible to all but one emulator or a real machine.

[Barnacle boy]

It reflects what most people in this thread said about the C64 palette yes, that it's got concessions because it was essentially built from a need to keep the silicon overheads down but is, in the long run and probably more through luck than judgement, very fit for the job in hand ...

Indeed. Surprisingly fit for the job in hand, really. The fact that it's difficult to come up with a better fixed 16-colour palette says a lot. I tried some time ago, and in the end about the only change I was happy with was sacrificing the lightest grey in favour of an additional, darker green (I'm sure that will delight dimensionX!). And maybe make the white a very bright grey to compensate (full white can be a bit overkill anyway).

 

There was a suggestion in that thread to ditch the purple in favour of something else, but come on... no grapes, no plums, no purple aliens? Fuhgeddaboutit!

[PeteD]

Yes, any example code, snippets of info etc would be handy I've done the basic player that does bugger all atm other than play patterns. It needs sounds and it may as well have all the newly discovered stuff I've got a bit of it sussed but better that I make sure and get any other bits and bobs anyone has.

 

I assume it's going to be a hardware waves and volume envelopes thing?

 

Pretty much whatever people ask for within reason.

 

I think multiple calls per frame to get closer to SIDs ADSR times for people wanting to try to recreate SID voices, but to save CPU I'd like to steer clear of the way most multiple call stuff works and basically just do register stuffing on the subsequent calls rather than go through the whole "play a note" code on each call only to find all it needs to do is change a volume register. I think 2ms might be within the realms on reason

 

 

Pete

[PeteD]

It reflects what most people in this thread said about the C64 palette yes, that it's got concessions because it was essentially built from a need to keep the silicon overheads down but is, in the long run and probably more through luck than judgement, very fit for the job in hand ...

Indeed. Surprisingly fit for the job in hand, really. The fact that it's difficult to come up with a better fixed 16-colour palette says a lot. I tried some time ago, and in the end about the only change I was happy with was sacrificing the lightest grey in favour of an additional, darker green (I'm sure that will delight dimensionX!). And maybe make the white a very bright grey to compensate (full white can be a bit overkill anyway).

 

There was a suggestion in that thread to ditch the purple in favour of something else, but come on... no grapes, no plums, no purple aliens? Fuhgeddaboutit!

 

I think you're right about the green although I do like the way the limitations of things like that gave C64 graphics a style of their own, like using brown instead of a dark green which I suppose to some people looks like an abomination but to me it's nice because it's different.

 

 

Pete

[TMR]

I tried some time ago, and in the end about the only change I was happy with was sacrificing the lightest grey in favour of an additional, darker green (I'm sure that will delight dimensionX!).

 

i thought his issue was with the ubiquity of the dark green...? i saw the comment from one person about the light green, but i like that one personally; i seem to remember building attack waves for Co-Axis 2189 where half are one shade and the rest use the other, alternating as they arrive on screen.

 

There was a suggestion in that thread to ditch the purple in favour of something else, but come on... no grapes, no plums, no purple aliens? Fuhgeddaboutit!

 

[Points at own avatar] Yeah, got to have purple aliens. =-)

[Barnacle boy]

I think you're right about the green although I do like the way the limitations of things like that gave C64 graphics a style of their own, like using brown instead of a dark green which I suppose to some people looks like an abomination but to me it's nice because it's different.

 

I know exactly what you mean Pete, and it relates to the point raised earlier about reflected/ambient light and the way objects are affected by the colour of their surroundings.

 

Sticking to the same shades at differing luminance can make things a bit sterile sometimes.

 

For example, I actually prefer this:

 

 

 

...to this:

 

 

The second one still looks good, but to me it's a little sterile, not earthy enough. (Yeah, yeah, I know it's meant to be in the cold depths of space or something, but still!)

 

 

i thought his issue was with the ubiquity of the dark green...?

 

I think he feels the darker green in the c64 palette is too light/bright and hence too distracting. I've never had a problem with that green, but another darker one could come in handy. Come to think of it, the lighter green in the palette could have probably been ditched, with either cyan or yellow stepping in to fill the gap depending on the coolness or warmth of the scene.

Edited May 10, 2010 by Barnacle boy