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Schmutzpuppe

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I'm aware of that. But if you want to do it again then it takes mumble cycles to reload all three registers' date=' during which time NO color changes can occur. TNSTAAFL.

 

Sticking to LDA/STA provides a steady stream of color change zones. This would be much easier to write a general conversion algorithm around than one that had to figure out where to wedge burst write/reload cycles.[/quote']

 

Okay, I'm talking about a way to create Atari pictures on a PC where you micromanage every graphic element and every cycle to get the best possible optimized display possible on the A8. That means stuffing color color registers, and possibly stuffing player data and moving players all in mid line, not offering a few extra colors in predictable bands. This would be the Ultimate MCS-type tool. Right now it's just too hard to design pictures this way by hand coding.

 

-Bry

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And I'm pointing out that the degree of micromanagement required to fully exploit this type of kernel is beyond the capacity of a sane human. I reiterate-- GED has been out for years, and I haven't seen a single picture generated by it.

 

Machine translation is the way to go.

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Cycle exact micromanagement in a graphic tool is a hard thing to do (but surly possible).

The highest rate of register changing in the Druid picture needs 56 cycles, it's an ordinary lda/sta sequence, most of the time you don’t need that much changes in a scanline.

A tool that can handle that would be enough to create druid like picture.

This would be a good first step I guess.

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Frohn: So you're saying that PAL actually requires the color info from 2 lines to create each line?

 

NTSC = Independent UV on each line

PAL = Averaged UV from 2 lines

SECAM = U & V from separate lines

 

Doesn't this create a loss of resolution on PAL? Would an NTSC screen be sharper?

 

having a high resolution on luminance and a low resolution on color tone is the idea behind ALL these three formats. the reason is very simple: the human eye can see luminance contrasts very good while it is very lazy to see color tones.

 

also on a normal tv picture you will have lot's of luminance contrast and nearly no color tone contrast anyway. for example, a wooden table has the same color tone all over, but the luminance gives all the detail to it. same for anything else (cars, walls, human faces etc etc etc) so that strategy not only fits the human eye pretty well, it also fits what you encounter in reality. (ofcourse, since otherwise the human eye would work different)

 

when engineers invented pal they wanted to get rid of some typical ntsc problems. also they made the resolution a bit more "square" so they gained a bit horizontal resolution for sacrificing vertical resolution. (ntsc has a very low horizontal color tone res while it has full res at the vertical).

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On the first half (when RAM refresh takes place) you can move a register-change 2 gr.0 char-widths left or right' date=' which gives less flexibility. You can also only change half the amount of registers in the first half, compared to the second half. You have to take great care of this assymetry, when writing an editor.

[/quote']

 

 

The assymetry due to DMA and refresh is not THAT problem because it is allways the same (when using allways the same Gr.-Mode)... even the problem with charmodline 0 is to handle by a bit cleverness. Please remember that it is possible to set the PM in blocks to compensate that.

 

One thing concernes me: The DMA-cycle and Memory Acces of every command. As you wrote, the NOP reads in one cycle from memory an the other is one cycle inside the cpu only.

What is happening with LDA? STA?

 

LDA -> one cycle read from Memory and one inside the CPU?

STA -> two cycle or four cycles on memory write?

 

AFAIK the dependence on CPU cycles and ANTIC DMA is allways the same... otherwise a fullscreen DLI (Kernal) would flicker. But it does not. You have only to set one WSYNC at the top of the screen and everything works fine.

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And I'm pointing out that the degree of micromanagement required to fully exploit this type of kernel is beyond the capacity of a sane human. I reiterate-- GED has been out for years' date=' and I haven't seen a single picture generated by it.

 

Machine translation is the way to go.[/quote']

 

I'm going to shut up and disagree. When you only have a few colors with horizontal restrictions to work with, you cannot translate pictures with any degree of accuracy. They will always come out wierd with visible color zones and bands. An MCS-type mode will never be suitable for photographic images (Use GTIA tricks for that stuff). The best low color computer art has always been hand drawn stuff that makes best use of the color limitations. I wanted to discuss an editor for those computer artists - one that could produce things like that OXYRON C64 picture that everyone likes so much.

 

-Bry

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I wanted to discuss an editor for those computer artists - one that could produce things like that OXYRON C64 picture that everyone likes so much.

 

 

Pictures like the OXYRON are not possible as they are shown. Only Interlace and ANTIC E+F interleave will help.

 

 

 

When you only have a few colors with horizontal restrictions to work with' date=' you cannot translate pictures with any degree of accuracy. They will always come out wierd with visible color zones and bands.

 

[/quote']

 

To create "photographic" pictures everyone has to drop of the "allways repeating coloreffects" thinking...

The pictures have to be created in layers.....and so on... but:

 

I guess, you are right with that "give up to produce software like this for the A8" thinking.

When people - that are producing Software day in and day out - are not able to put some code onto the PC for creating A8 Tools, how can it some little A8 homebrewers?

The only way would be to spend millions of dollars or euros to put a coding crew together..... unbelievable... isn't it? The destination is done at least.

Am I Mr. Billion? No.... so such software will never be there... sad... sad.

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I wanted to discuss an editor for those computer artists - one that could produce things like that OXYRON C64 picture that everyone likes so much.

 

 

Pictures like the OXYRON are not possible as they are shown. Only Interlace and ANTIC E+F interleave will help.

 

Umm.. Did anyone else see that? Emkay said something is not possible! :o

 

I think it may be possible (or at least a reasonable facsimile) if you use all 5 players and throw enough CPU cycles at it (does that picture use sprites?).

 

 

When you only have a few colors with horizontal restrictions to work with' date=' you cannot translate pictures with any degree of accuracy. They will always come out wierd with visible color zones and bands.

 

[/quote']

 

To create "photographic" pictures everyone has to drop of the "allways repeating coloreffects" thinking...

The pictures have to be created in layers.....and so on... but:

 

I guess, you are right with that "give up to produce software like this for the A8" thinking.

When people - that are producing Software day in and day out - are not able to put some code onto the PC for creating A8 Tools, how can it some little A8 homebrewers?

The only way would be to spend millions of dollars or euros to put a coding crew together..... unbelievable... isn't it? The destination is done at least.

Am I Mr. Billion? No.... so such software will never be there... sad... sad.

 

I had a hard time understanding this part, but...

 

All kinds of cool A8 stuff has been done on the PC already. There's a lot of it going on for 2600 development as well. It can happen.

 

-Bry

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Umm.. Did anyone else see that? Emkay said something is not possible! :o

 

I think it may be possible (or at least a reasonable facsimile) if you use all 5 players and throw enough CPU cycles at it.

 

 

You can do it by creating a new GTIA that is showing colors instead of only a brightness variation of the background.

 

Better? ;)

 

 

 

All kinds of cool A8 stuff has been done on the PC already.

 

 

 

Really?

 

Let's take a look at the POKEY and the SID Emulation...

 

C64 users are lamenting on the "worse" SID emulations.... In fact there are some effects not played correct.... You can check it Here

With the SID you have a complex synth-chip and the emulation has some effect issues...that's all

 

Most A8 users are happy about the "good" SAP Pokey emulation...but only the simple 4x 8bit channel function is working properly and filtering is listenable. The other functions are not even a bit buggy... they are simply not working and no one is recognizing it...

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You can do it by creating a new GTIA that is showing colors instead of only a brightness variation of the background.

 

Better? ;)

 

?? There's a GTIA mode that allows 9 colors' date=' but the resolution is the problem. You won't get a better 160 mode unless Antic can read more data.

 

All kinds of cool A8 stuff has been done on the PC already.

Really?

 

Let's take a look at the POKEY and the SID Emulation...

 

C64 users are lamenting on the "worse" SID emulations.... In fact there are some effects not played correct.... You can check it Here

With the SID you have a complex synth-chip and the emulation has some effect issues...that's all

 

Most A8 users are happy about the "good" SAP Pokey emulation...but only the simple 4x 8bit channel function is working properly and filtering is listenable. The other functions are not even a bit buggy... they are simply not working and no one is recognizing it...

 

There's more being done for the 64 because it has a bigger following. Maybe if we can get Curt Vendel to produce a better scan of Pokey's internals, we can figure out how to improve emulation.

 

-Bry

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NOPs take indeed 2 cycles' date=' but when the screen is being drawed you still have the {first half} - {second half} problem. In the second half every other cycle is stolen by graphics DMA, but a NOP only needs 1 cycle for memory access (Opcode fetch) as it doesn't do anything else with the memory. So the 2nd NOP cycle is executed by the 6502 when Antic uses memory. That's why you can move a register-change exactly 1 gr.0 char- width left or right (when drawing the second half).[/quote']

 

Where did you get that info? I still think that Antic stops the CPU completely, so if the second cycle of an instruction is pending, it's simply frozen by Antic.

 

The undocumented 3cycle NOP

 

Aren't 3 cycle nops just void reads from the memory?

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Where did you get that info? I still think that Antic stops the CPU completely' date=' so if the second cycle of an instruction is pending, it's simply frozen by Antic.[/quote']

 

You're right. If Antic is on the bus, then the CPU is stopped. Antic has no way of knowing that the current cycle is part 2 of a NOP (the 6502 has no Memory Request pin so it is assumed that every cycle is a read or write).

 

The undocumented 3cycle NOP

 

Aren't 3 cycle nops just void reads from the memory?

 

Well, they're instructions that don't have any effect. Look at the undocumented opcodes, and you'll see there are a lot of them with different clock lengths.

 

-Bry

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You can do it by creating a new GTIA that is showing colors instead of only a brightness variation of the background.

 

Better? ;)

 

?? There's a GTIA mode that allows 9 colors' date=' but the resolution is the problem. You won't get a better 160 mode unless Antic can read more data.

[/quote']

 

 

erm.... you know that ANTIC is only a bit-junky ? All you see on the screen is build by the GTIA. I don't know how exactly it is done, but GTIA knows when a bit-mode or a color mode is requested. The bit modes ANTIC 2 or F are still showing only a different luminance... but that is nothing new for you.

To create better results in colors at high-resolution an enhanced GTIA with a kind of color RAM would have been necessary...

What a clever act this would have been if ATARI did not only create the GTIA-Overlays, but a programmable Overlay in blocks....

Well ... Commodore did know it was the cheapest way to create colorfull picures.

 

 

There's more being done for the 64 because it has a bigger following. Maybe if we can get Curt Vendel to produce a better scan of Pokey's internals, we can figure out how to improve emulation.

 

 

Thre real worse on this is that nearly everone does not know what would be possible. That's why the emulation is lacking, because the coders of the emulation are not knowing it too.

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erm.... you know that ANTIC is only a bit-junky ? All you see on the screen is build by the GTIA. I don't know how exactly it is done' date=' but GTIA knows when a bit-mode or a color mode is requested. The bit modes ANTIC 2 or F are still showing only a different luminance... but that is nothing new for you.[/quote']

 

Here's how it works. Forget GTIA modes for a minute (CTIA modes only), then GTIA only has 2 display modes:

 

(A) 320 x 2 colors

or

(B) 160 x 5 colors

 

That's it. All other modes are created by Antic using one of those 2 modes.

 

To create mode 2, 3 & F, GTIA is put into mode A at the beginning of a line.

 

To create modes 4, 6, C & E, GTIA is put into mode B at the beginning of a line. Modes 5, 7, B, and D are created when Antic buffers the last line and sends it a 2nd time.

 

To create modes 9 & A, GTIA is put into mode B and Antic reads data more slowly, sending every pixel twice, and sending the buffered line a 2nd time.

 

To create mode 8, GTIA is put into mode B and Antic reads very slowly, sending every pixel 4 times, and sending the buffered line 7 more times.

 

To create better results in colors at high-resolution an enhanced GTIA with a kind of color RAM would have been necessary...

What a clever act this would have been if ATARI did not only create the GTIA-Overlays, but a programmable Overlay in blocks....

Well ... Commodore did know it was the cheapest way to create colorfull picures.

 

Well, when the 800 was released, it was the most colorful computer you could buy. The 64 came later and had a different display method. I don't think you can fault Atari for what they designed in the '70s.

 

I had a thought on a mode that almost could have been done. Antic is capable of reading at several speeds. It usually reads at every other cycle, or every 4th cycle depending on the mode. At the most, it can use every cycle. It does this when reading the 1st line of mode 2, 3, 4 & 5, because it must not only read a line of graphics (40 bytes), but also a list of 40 characters to display (there are 80 cycles across the Playfield area). If Antic had a mode where it could use all CPU cycles to read a 160 x 16 color mode (1 byte every CPU cycle means 4 bits every pixel clock), it would be very cool. There's a problem, though, and that is that RAM refresh doesn't happen on these maxed out lines. If you did one after the other you would lose the contents of RAM. That's why Antic only allows it in 1 line out of every 8.

 

There's more being done for the 64 because it has a bigger following. Maybe if we can get Curt Vendel to produce a better scan of Pokey's internals, we can figure out how to improve emulation.

 

 

Thre real worse on this is that nearly everone does not know what would be possible. That's why the emulation is lacking, because the coders of the emulation are not knowing it too.

 

Well, that's why we have Forums like this. To figure out what's left to do (and to keep me from getting my work done). :)

 

-Bry

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I think it may be possible (or at least a reasonable facsimile) if you use all 5 players and throw enough CPU cycles at it (does that picture use sprites?).

 

Nope' date=' when that's onscreen (it's part of a slideshow at the back end of [b']Deus Ex Machina[/b] by Crest) there's a sprite generated upscroller moving over the top of it using all eight hardware sprites - that picture is purely 160x200 multicolour bitmap with no tricks.

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Nope' date=' when that's onscreen (it's part of a slideshow at the back end of Deus Ex Machina by Crest) there's a sprite generated upscroller moving over the top of it using all eight hardware sprites - that picture is purely 160x200 multicolour bitmap with no tricks.[/quote']

 

Thanks. I'll check that demo out.

 

I have a question. Do you think an Atari programmer would have lasted as long in a 64 forum as you have here? :) Last time I jumped in to a 64 forum (a long time ago- to defend the A8 against some misinformation) I got my butt handed to me in a hurry.

 

-Bry

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To create modes 9 & A' date=' GTIA is put into mode B and Antic reads data more slowly, sending every pixel twice, and sending the buffered line a 2nd time.

 

[/quote']

 

It looks like GTIA loses the mode B setting when playing with GTIA-Modes mid-scanline. Or the mode A has a higher priority...

 

 

 

 

Well, when the 800 was released, it was the most colorful computer you could buy. The 64 came later and had a different display method. I don't think you can fault Atari for what they designed in the '70s.

 

 

 

Please don't forget, the 800XL was released when the C64 was..

But ATARI suffered by a kind of anti-evolution.

Perhaps they did the most colorfull computer in 1978. In 1983 a computer with allmost the same hw was released. And... referring to the PAL ATARI XE, the videoquality was/is extremely worse compared to the 800XL. I don't know if it was the same on the NTSC machines.

 

 

 

 

Well, that's why we have Forums like this. To figure out what's left to do (and to keep me from getting my work done). :)

 

 

I do think so too (exept that in the brackets ;) )

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Nope' date=' when that's onscreen (it's part of a slideshow at the back end of Deus Ex Machina by Crest) there's a sprite generated upscroller moving over the top of it using all eight hardware sprites - that picture is purely 160x200 multicolour bitmap with no tricks.[/quote']

 

Thanks. I'll check that demo out.

 

I have a question. Do you think an Atari programmer would have lasted as long in a 64 forum as you have here? :)

 

 

 

 

It looks like, that an ATARI-User with an open mind has more problems to outlive in this forums :roll: :ponder: ;)

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It looks like GTIA loses the mode B setting when playing with GTIA-Modes mid-scanline. Or the mode A has a higher priority...

 

Messing with GTIA settings in mid scanline does cause it to lose the mode Antic requested. This "feature" can be handy. :)

 

Please don't forget' date=' the 800XL was released when the C64 was..

But ATARI suffered by a kind of anti-evolution.

Perhaps they did the most colorfull computer in 1978. In 1983 a computer with allmost the same hw was released. And... referring to the PAL ATARI XE, the videoquality was/is extremely worse compared to the 800XL. I don't know if it was the same on the NTSC machines.[/quote']

 

Well, it's true that Atari never improved the hardware for the 8-bit line (and until the buyout, they never did much toward a new design either). But look at other companies like Apple- they kept re-packaging the Apple II/II+/IIe/IIc as well. Commodore developed new 8-bit hardware but it wasn't 64 compatible and no one's sure why. It seems every company in the early days suffered from some sort of schizophrenia.

 

As far as NTSC goes, the best looking output is probably the XE, followed by the 800, then the XL which had a terribly botched video circuit.

 

-Bry

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I have a question. Do you think an Atari programmer would have lasted as long in a 64 forum as you have here? :) Last time I jumped in to a 64 forum (a long time ago- to defend the A8 against some misinformation) I got my butt handed to me in a hurry.

 

Depends on the board and how it's approached really' date=' somewhere like comp.sys.cbm only bites if they feel they're being attacked (for example, the "annual" comp.sys.sinclair invasion that usually bleeds out into large chunks of comp.sys.*) and i suspect that's the same for just about every format. The Speccy crowd see the "my computer is better" arguments as part of their enjoyment of the machine i suspect, although they don't admit it! =-)

 

As such, the most "volatile" group i've come across is possibly the forum at World Of Spectrum (where my beloved C64 is referred to as the Commode) but i seem to be at least tolerated if not totally accepted (me being a hardcore fan of [b']Chronos[/b] helps, i suspect! =-) At the same time, one person who registered to take the piddle out of the Spectrum's sound capabilities got a few important bits chewed off and then had his arse handed to him when he heard what a Spectrum can really do.

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Out of all the computers to rabidly defend, I find the Spectrum to be an odd choice. :)

 

-Bry

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Spectrum users are very loyal to their machine, possibly because it's quite simple as hardware goes. But the games do bear them out in some respects, like any 8bit it has it's share of rank stuff but there are some absolute gems there too. And for a machine with no hardware smooth scrolling or sprites and a bitmap-based screen, something like Chronos or the conversion of Zybex is quite an achievement...

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