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2005-06-11 12:56

Scout

Registered: Dec 2002
Posts: 1570

DTV vs. C64

With interest I read the DTV and the DTV vs. C64 articles in Driven #31.
Esspecially reading the tech specs of the DTV v2/pal made me very enthousiastic.
Reading the con's of the (30 dollar/euro) DTV according to some sceners it "amazed" me that they put it on the same shelf as the (300 dollar/euro) SuperCPU and C-1, expecting that there would be no interest in building a demoscene around the DTV.
Besides the fact that the DTV isn't a real C64, it should be a 8 bit coders dream!

Krill wrote in his article that the bounderies of the C64 still aren't found yet (on which I completely agree).
He also wrote that this is also the reason of not coding for the DTV.
Why not? The DTV isn't a C64 rival, it's just a new -affordable- platform based on the C64 (and yes, on the C-1 too) with loadsa new stuff to explore.

What do you think about a DTV-scene?

R.
---
-= Silicon Ltd. =-
http://www.deco-design.com/scl

2005-06-11 13:27

Slartibartfast
Account closed

Registered: Jul 2002
Posts: 230

Yeah, I agree. I think that the price of the DTV definitely will play a large part in it's take-up by people interested in coding it. I also think that the SCPU's cost is a factor that has restricted interest in development for that.

For myself, the new DTV has some amazing new tech in it and I look forward to having a hack at it, and also seeing what can be done when these specs are really pushed.

Right now, my brain is worn out, so I'll probably add some more DTV evangalism later as normally I never shut up about it's possibilities ;)

One thing I will say now. Chrome will definitely be releasing a demo on the DTV. :)

2005-06-11 15:48

Radiant

Registered: Sep 2004
Posts: 639

The specs of DTV v2 make me a happy panda indeed, and I intend to acquire one ASAP. I view it not as an expanded C64, but rather as some kind of follow up, like the A1200 should have been compared to the A500. I'm just dying to see what tricks it will be capable of.

I will certainly not forfeit the C64 scene just because of it, however - Krills points are perfectly valid in that sense. I do not believe it will "take over" the C64 scene, but I hope another scene will form around it.

The future is again starting to look bright for us hobbyist computer enthusiasts, for the first time in many, many years.

2005-06-11 22:44

Krill

Registered: Apr 2002
Posts: 2969

Scout: I basically wrote that _for me_, a DTV is nothing to code on. Basically it's because I have (like almost everybody here I think) only limited spare time to spend with computers. That is, I don't want to "waste" time with the DTV because that would keep me away from new C64 productions. I am interested in other systems as well (I plan to do some guest code for Amiga or even PC productions some far day), but in that regard, the DTV is just too close to an 8-bit system like the C64, and so I prefer the original.

I think many of the other well-known C64 demo coders think similar, yet I think one or the other will try his abilities with a DTV. But after all, i'm pretty sure we all prefer the C64 and will still emphasize our scene efforts on it.

2005-06-14 03:42

Wildstar

Registered: Nov 2004
Posts: 50

Quote: Scout: I basically wrote that _for me_, a DTV is nothing to code on. Basically it's because I have (like almost everybody here I think) only limited spare time to spend with computers. That is, I don't want to "waste" time with the DTV because that would keep me away from new C64 productions. I am interested in other systems as well (I plan to do some guest code for Amiga or even PC productions some far day), but in that regard, the DTV is just too close to an 8-bit system like the C64, and so I prefer the original.

I think many of the other well-known C64 demo coders think similar, yet I think one or the other will try his abilities with a DTV. But after all, i'm pretty sure we all prefer the C64 and will still emphasize our scene efforts on it.

I agree in most base points but I will likely do some work for the DTV v2 as well as the C64 despite limited time.

There is always time to come up with a piece here and there. A co-C64/DTV v2 demo would be cool and when it detects a DTV, it would show a special DTV specific part.

A cool factor to look into. Much of the coding will be extending on existing knowledge in C64. I will be looking into doing a DTV v2 pic. It would be quite a COOL thing.

A 1/4th screen logo in the 8bpp mode would be like 16K.
Especially if a split is used to shift into another video mode for a scroller that uses fonts that uses some of the DTV enhancements in the v2 DTV.

Imagine a variety of new and enhanced effects. I find that cool to try out. I hope you try out every once in awhile a few things. I believe some C64 sceners will join the DTV scene to form it BUT I doubt they'll leave the C64. It would be a good thing and is what I expect and hope for.

Heck, there are some C64 sceners doing stuff for non C= based stuff.

2005-06-14 14:22

Six

Registered: Apr 2002
Posts: 293

"A 1/4th screen logo in the 8bpp mode would be like 16K.
Especially if a split is used to shift into another video mode for a scroller that uses fonts that uses some of the DTV enhancements in the v2 DTV."

This can be tricky. I tried to split the screen between 8bpp and FRED, but it didn't work.

At first I didn't understand why, but upon further investigation, it became clear. It may be possible to do this with some modulo tricks, but it will probably require having some dead lines or glitchy space that you have to cover somehow.

The video counters get their base at the beginning of each frame. There is no way to reset that base inframe. At the beginning of each line, the chip takes that base and calculates the current pixel address based on line#*usage.

For example...If you start with an 8bpp pic at $020000, and use a raster interrupt to switch into FRED mode at screen line $60, you would expect the data displayed in the FRED part of the screen to be from around $023980.

($60-$32=$2e*$140=$3980+our base of $020000= $023980)

It would be logical to expect that it would simply continue at the next address, but it won't.

Because the line address is calculated at the beginning of each line using the CURRENT mode as a reference, and FRED is 40 bytes per line instead of 320, you will actually be displaying data from around $020730, which is smack dab in the middle of your 8bpp logo.

You have to get creative with the modulo to combat this, or simply resign yourself to the machine's limitations and put your 8bpp logo at the bottom 1/4 of the screen because you're lazy, like me ;)

2005-06-14 23:38

Wildstar

Registered: Nov 2004
Posts: 50

Quote: "A 1/4th screen logo in the 8bpp mode would be like 16K.
Especially if a split is used to shift into another video mode for a scroller that uses fonts that uses some of the DTV enhancements in the v2 DTV."

This can be tricky. I tried to split the screen between 8bpp and FRED, but it didn't work.

At first I didn't understand why, but upon further investigation, it became clear. It may be possible to do this with some modulo tricks, but it will probably require having some dead lines or glitchy space that you have to cover somehow.

The video counters get their base at the beginning of each frame. There is no way to reset that base inframe. At the beginning of each line, the chip takes that base and calculates the current pixel address based on line#*usage.

For example...If you start with an 8bpp pic at $020000, and use a raster interrupt to switch into FRED mode at screen line $60, you would expect the data displayed in the FRED part of the screen to be from around $023980.

($60-$32=$2e*$140=$3980+our base of $020000= $023980)

It would be logical to expect that it would simply continue at the next address, but it won't.

Because the line address is calculated at the beginning of each line using the CURRENT mode as a reference, and FRED is 40 bytes per line instead of 320, you will actually be displaying data from around $020730, which is smack dab in the middle of your 8bpp logo.

You have to get creative with the modulo to combat this, or simply resign yourself to the machine's limitations and put your 8bpp logo at the bottom 1/4 of the screen because you're lazy, like me ;)

Fair enough thought. Either way, it is cool. If I recall - a good modulo for the split would be requireing 1-2 rasterlines for this 'glitch' space which is fair enough. As most font scrollers should be at least 2 rasterline below such a pic. Most tricks I have done on the gfx side is leave in at least 2 rows of black rasterlines below my pic. Where the black raster lines are would be where the coder would begin the split.

As a dead line that has its foreground color = background, should not be visible.

In fact I like a little bit of space between the logo and a scroll.

2005-06-19 22:46

Tch
Account closed

Registered: Sep 2004
Posts: 512

Hmm,as I see this thread is not progressing,I thought I´d just speak my mind.

The DTV sure seems to have nice extras.
And it might be fun to use it,no doubt.
But I think it has come,about 15 years too late.

I,for one,like the Commodore 64 and that is the reason why I am working on it again.
I don´t care for ´improvements´ as I have a PC that will beat those anyways.
The core of the scene,as I see it,is to get the best performance out of the C64.
And I think that many sceners agree with me.

Being a bad coder,I wouldn´t mind having a little extra rastertime. ;P
But regarding graphix,I like to explore the possibilities that have not been covered yet.

There is room for improvement,let it not be a ´hardware´-story! :)

2005-06-19 23:22

Radiant

Registered: Sep 2004
Posts: 639

Tch: "Improvements" in this case can not be accurately measured in numbers and compared with other platforms. What actually counts is that we here have a new hardware platform, with features far less explored than those on the C64, where everything about i.e. the VIC-II is starting to become known by now. It's not about higher performance, it's about new, unsettled and unexplored land.

Just my take on the issue.

2005-06-21 14:50

Optimus

Registered: Jan 2002
Posts: 122

I understand why some democoders are not interested in the DTV. Some of us enjoy the challenge of coding something really funky in one static platform. Count me on. If you 've found a very nasty way to cheat an impossible effect, which the DTV can do easilly with it's extra hardware capabilities, then the second way wouldn't be that much fun as the first one.

However, I consider buying one DTV and perhaps coding something for it (if I ever find the time for that too), as I use to collect any machine with a demoscene and willing to code for few of them at times (my time doesn't permit to fiddle around with much, even if I'd love to ;). That's how I am personally going to see the DTV, as an alternative platform to code for, not as a saviour for the C64 or something..

So, I guess I agree with both opinions ;)

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