PTDS (Pixel Tetrads Dots / Speed) is a video system for AGA Amigas that provides pseudo-native chunky screens, i.e. screens where each byte in CHIP RAM corresponds to a dot on the display - in other words, it offers chunky screens without chunky-to-planar conversion.

Download: https://www.retream.com/PTDS

Some examples:
* https://www.youtube.com/watch?v=0xunQ6ldVKU
* https://www.youtube.com/watch?v=4eikEo45v1I
* https://www.youtube.com/watch?v=eVzTIyg_MeE
* https://www.youtube.com/watch?v=ebxwKm9K4Os
* https://www.youtube.com/watch?v=tLtLhJXInOY
(Due to technical limitations, the video quality is lower than the actual one.)

For the details, please refer to the documentation included in the archive.

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RETREAM - retro dreams for Amiga, Commodore 64 and PC

@saimo

Thanks for sharing PED81C. Can you tell us any more about it? I'm interested in how you technically made it possible?

Yes I downloaded it and watched the videos but a brief description would be good before I unpack it.

An idea? How about Doom? Yes it's been done to death but Amiga people seem to love it.

3d tends to come to mind first when chunky is mentioned.

Of course there is possibility of interesting 2d using chunky methods.

@Hypex

Quote:

Thanks for sharing PED81C. Can you tell us any more about it? I'm interested in how you technically made it possible? Yes I downloaded it and watched the videos but a brief description would be good before I unpack it.

The documentation in the archive contains all the information you could possibly ever want

Quote:

An idea? How about Doom? Yes it's been done to death but Amiga people seem to love it.

I don't, though!

Quote:

3d tends to come to mind first when chunky is mentioned. Of course there is possibility of interesting 2d using chunky methods.

Sure, plenty of possibilities...

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RETREAM - retro dreams for Amiga, Commodore 64 and PC

Uploaded an archive with updated documentation.
While at it, given that I was asked for a source code example, I whipped up an AMOS Professional program that shows how to set up a PTDS screen and to perform some basic operations on it - hopefully, this will be easy to understand and also open the door to AMOS programmers. The program source is included in the archive.

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RETREAM - retro dreams for Amiga, Commodore 64 and PC

I have just released a little update, accompanied by the PTDS Voxel Engine (PVE), i.e. a new demo. If you can't be bothered trying it yourself, you can see it in this video - but beware: YouTube's video compression degraded the visual quality (especially the colors saturation and brightness).

https://www.youtube.com/watch?v=0xunQ6ldVKU

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RETREAM - retro dreams for Amiga, Commodore 64 and PC

@saimo

Very nice, just lacks the blue sky with white clouds, and «WarpUP» ;)

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B5D6A1D019D5D45BCC56F4782AC220D8B3E2A6CC

Is this an evolution of your dot-matrix engine? Apologies in advance for mis-naming it...

@saimo

it is not worth time and work
buy graphics card for your amiga

@ppcamiga1

WTF? Are you for real?

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Indigo 3D Lounge, my second home.
The Illusion of Choice | Am*ga

@pixie

That's a bitter narcissist for ya. Kill any joy there is, no passion and arrogant AF.

@kolla

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Very nice, just lacks the blue sky with white clouds, and «WarpUP» ;)

I don't know what you're referring to, but I guess it must be some demo published back when WarpUp was being promoted, right? (Never been into PPC cards, so I barely know the names )

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RETREAM - retro dreams for Amiga, Commodore 64 and PC

@Lou

Quote:

Is this an evolution of your dot-matrix engine? Apologies in advance for mis-naming it...

No need to apologize!
It's the other way around: the dot-matrix engine was derived from PTDS

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RETREAM - retro dreams for Amiga, Commodore 64 and PC

@saimo

Ah, sorry, but yes you are quite correct :)

https://youtu.be/AZL86gZr0LA?si=4graLolmT0TvNuPf

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B5D6A1D019D5D45BCC56F4782AC220D8B3E2A6CC

@ppcamiga1

Quote:

it is not worth time and work buy graphics card for your amiga

I think you are severely mentally ill and need to be locked up in an institution.
This is how you react to some truly awesome development for amiga by true amiga fans?
You are mentally ill, you are toxic and you are a determent for any and all amiga fans and projects.

@saimo

Very impressive! What sort of frame rate are you getting on the 68030 out of curiosity?

Also, how does the performance compare to C2P on the same hardware for a similar logical pixel count?

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Doing stupid things for fun...

@Karlos

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Very impressive! What sort of frame rate are you getting on the 68030 out of curiosity?

These are the fps figures I have gathered until now:

Amiga 1200 / PiStorm32 + Raspberry Pi 3 A+ / 50.0
Amiga 1200 / Blizzard 1230 IV / 20.2
Amiga 4000 / Cyberstorm MK III / 18.8
Amiga 1200 / Blizzard 1260 / 16-20
Amiga 1200 / TerribleFire TF1260 / 14.2

The code is fine-tuned for 68030 (unsurprisingly: it's the only CPU I have ), but the bottleneck must be the access to CHIP RAM. I'm waiting for some tests to know exactly.
In this thread on EAB you can find the gory details (I know you want them) being discussed by me and paraj

Quote:

Also, how does the performance compare to C2P on the same hardware for a similar logical pixel count?

No idea: I never used a C2P routine in my life! Maybe a copyspeed C2P wins* on 68060 because the time spent for writing to CHIP RAM should be inferior thanks to the less busy CHIP bus.
*Also in terms on visual quality.

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RETREAM - retro dreams for Amiga, Commodore 64 and PC

Just released a new version of PVE. Full changelog below. In short: it's faster and it's got a few little additions.

https://retream.itch.io/ptds

v1.1 (22.12.2023)
* Reworked screen buffering, so that the raster data is more efficiently written to CHIP RAM when bitplanes DMA is inactive.
* Improved 68030 caches handling.
* Added 68040 and 68060 caches handling.
* Added MMU handling to avoid that the MMU affects the speed negatively.
* Optimized rendering core by making it write the dots sequentially.
* Made a little 68060-specific code optimization.
* Ensured 68060 susperscalar dispatch is enabled.
* Added live-toggable staggered lines video filter, which helps see better colors on devices that do not support SHRES and reduces the jailbars effect on devices that support SHRES (to enable/disable: [F1]).
* Made fps indicator live-togglable (to enable/disable: [F2]).
* Made quitting from the voxel screen return to the splash screen.
* Replaced mouse controls with keyboard controls.
* Added benchmark function.
* Added command line switches to control the CPU caches.
* Fixed bug that caused a longword to be written to a random location when the fps indicator was on.
* Fixed an innocuous initialization bug.
* Made cleanup code more robust.
* Updated, extended and fixed documentation.

Last edited by saimo on 19-Mar-2025 at 04:29 PM.

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RETREAM - retro dreams for Amiga, Commodore 64 and PC

It was ages that I intended to dig up some 20+ years old code and use it to play with PTDS a little more. Finally I got around to do it and came up with a new test program called Zoomaniac.
Details in the video and in the manual. Download available at https://retream.itch.io/ptds.

https://www.youtube.com/watch?v=eehqapb20fE

CHANGELOG

March 27, 2024
* Added the Zoomaniac demo.
* [PTDS Voxel Engine] Made a couple of minor changes.
* [PTDS Voxel Engine] Updated documentation.

January 1, 2024
* Rebuilt demos against latest custom framework.
* [PTDS Voxel Engine] Optimized slightly background rendering.
* [PTDS Voxel Engine] Corrected benchmark fps calculation (312 rasterlines were considered instead of 313).
* [PTDS Voxel Engine] Built against latest custom framework.
* [PTDS Voxel Engine] Updated, extended and fixed documentation.

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RETREAM - retro dreams for Amiga, Commodore 64 and PC

In response to the feedback received, I have uploaded a new version of Zoomaniac that allows to enable/disable the fps limit by means of [F3].

Quote:

* The number shown in the top-left corner of the effects screen is the fps indicator, which reports the number of frames rendered in the last second. It is limited to 999. * When the fps limit is on, the maximum number of frames rendered per second is 50 also on the most powerful machines, as the display refresh rate is 50 Hz. When the fps limit is off, frames are rendered without pausing when the previously rendered frame/frames has/have not (completely) displayed yet. On machines which cannot run the program at 50 fps or more, turning off the limit has no effect whasoever; on the other machines, the only visible effect is that the fps indicator goes beyond 50, thus giving a measure of the maximum speed that the machine can reach.

Also, this new version runs 1-2 fps faster on 68030 thanks to the data cache burst:

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* on 68030 tests proved that: it is advantageous to turn the data cache burst on when scaling a 128 dots wide rectangle to a rectangle wider than 8 dots (i.e. with an X scaling factor greater than 1/16); with a scaling factor of 1/16 or less the difference proved to be minimal when both the source and destination rectangles were 256 dots tall; considering that turning the data cache burst off would therefore be advantageous only with very narrow and tall rectangles (which are uncommon and intrinsically rather inexpensive), it is not worth it to implement a data cache burst management inside the scaling routine;

CHANGELOG

v1.1 (28.3.2024)
* Turned the 68030 data cache burst on for slightly faster performance.
* Made a couple of minor optimizations.
* Added frames rendering limit toggle ([F3]).
* Worked on fps indicator: added hundreds digit; made digits smaller; made digits auto-clearing, so that they read correctly also when they are not cleared before drawing.
* Made staggered lines toggle as soon as [F1] is pressed (instead of when it is released).
* Updated splash screen.
* Redesigned the 'M' in the logo.
* Updated and extended manual.

Last edited by saimo on 29-Mar-2024 at 01:49 PM.

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RETREAM - retro dreams for Amiga, Commodore 64 and PC

To have a complete set of scaling routines (which hopefully I'll use for something someday), I added support for color-keying, zero-keying (color-keying with color 0), and horizontal and vertical flipping.
Morever, given that initially the focus was on the stock A1200, the performance on expanded machines was not optimal (as the rendering was done directly in CHIP RAM), so I added also an alternative buffering method that, when 2 rasters can be allocated in FAST RAM, allows rendering in FAST RAM and then copies the rendered raster to the raster in CHIP RAM as quickly as possible, starting when the beam reaches the bottom of the screen. This, relatively to the first effect in the test program (which is the only one whose performance was measured until now), produced a gain of 8-9 fps on my 68030-equipped Amiga 1200.

The updated test program (available at https://retream.itch.io/ptds), to demostrate the new features, streches and shrinks a color/zero-keyed texture covering almost the entire screen over a full-screen zooming background, with all the possible flipping combinations. That is of course a bit taxing for a stock A1200, whose performance drops between 12 and 16 fps in the busiest cases.

https://www.youtube.com/watch?v=ebxwKm9K4Os

(Side note: the video was recorded before finalizing the test program, so it shows an outdated splash screen and zooming jumps relatively to the background when passing from/to the color/zero-keying effects.)

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RETREAM - retro dreams for Amiga, Commodore 64 and PC