Getting the most from C128's VDC chip w/ idun-cartridge. Higher quality graphics/easier programming.

Рет қаралды 3,101

7 ай бұрын

A deeper discussion and demonstration of idun-cart's VDC software.
GitHub: github.com/idun-project/idun-...
Hackaday: hackaday.com/2023/04/17/a-new...
Buy: www.tindie.com/products/idun-...

Пікірлер: 20

@vanhetgoor 6 ай бұрын

Back in the '80's we still had a long way to go. We all looked at the same primitive pictures and then we thought that milestones were reached. The bouncing ball, the pharaoh, the loin, in those day it was for computer enthusiasts almost impossible to draw something, the few pictures all were converted from a video digitiser on a big computer to the Amiga. There were great expectations but games never worked in het highest resolution, simply because the machines were not capable to move around large fragments of the screen.

@johnsmith1953x Ай бұрын

That's the whole reason of using sprites and coppers.

@BikeArea 7 ай бұрын

Thanks a lot for this profound explanation and presentation! ✌️

@JohnMDiLiberto 7 ай бұрын

Very interesting! I only had one friend (back in the day, of course) who upgraded to the 128, and I don't recall spending too much time investigating that gem with him.

@idunproject 7 ай бұрын

Similar story here.

@megatech1966 7 ай бұрын

Very cool. Will try them out later.

@johnsmith1953x Ай бұрын

The regular C128 only had 32k. You had to exand the internal VRAM to 64k to do this. The C128D came with a full 64k and had some other tricks.

@soviet9922 6 ай бұрын

amazing

@siener 6 ай бұрын

Man, this really makes me wish that I had a 128. It's a pity they're so rare and so expensive. I'll keep on looking on EBay. Maybe one day...

@idunproject 6 ай бұрын

Yes, it's a shame they are often pricey. I still see some good deals from the UK, occasionally.

@victokra 6 ай бұрын

Would it have killed you to mention the "inspiration" for most of the modes you demonstrated? Namely my "VDC Mode Mania" and "VDC Spectrumania"-demos? You are even using most of the same pictures I originally converted for these modes. I appreciate the effort you took into building something larger out of this, but at least a mention would have been appropriate, I think.

@idunproject 6 ай бұрын

But, I DO specifically mention the "VDC mode mania" demo @19:19

@victokra 6 ай бұрын

@@idunproject Oops, ok then. Did not find that on first skim-through, sorry. Then I guess it's just about VDC Spectrumania ;-)

@idunproject 6 ай бұрын

@@victokra No problem. And for the record, thank you for showing the way with all your past demos!

@gertachimrenel595 7 ай бұрын

You should add 720x350 and 720x700 monochrome, this is the resolution of the Hercules graphics card. There are some videos of Monkey Island in Hercules mode on KZfaq.

@idunproject 7 ай бұрын

You're right. I bet those modes could be interesting with the right foreground/background colors and a nice 16-pixel high character set.

@gertachimrenel595 7 ай бұрын

Also interesting would be quarter-PC resolutions: QuSVGA 400x300 and QuXGA 512x384. They are small, but based on a standard, and they can be in color. These modes are also interesting because the Amiga AGA chipset has these: Super72 LoRes and HighGfx LoRes. This would allow drawing images in DeluxePaint and then converting them to VDC format. And because the Amiga can read and write 1581 disks it is very easy to exchange files.

@gertachimrenel595 7 ай бұрын

I'd recommend to give the modes names known from the PC and the Amiga. It is also better to sort them by resolution and color type. Here's my list to support most classic computers: Mode 1 320x200 - NTSC² Mode 2 320x240 - QVGA¹ Mode 3 320x256 - PAL¹ Mode 4 368x352 - D20¹ Mode 5 400x300 - QSVGA² (or Super72) Mode 6 512x384 - QXGA² (or HighGfx) Mode 7 640x200 - MedRes¹ Mode 8 640x400 - HiRes¹ Mode 9 640x480 - Productivity¹ Mode 10 640x480 - VGA² Mode 11 512x342 - MCC³ Mode 12 640x400 - Mono³ Mode 13 640x480 - MVGA³ Mode 14 720x350 - Hercules³ Mode 15 720x700 - Hercules2³ Mode 16 800x600 - MSVGA³ The modes marked with ¹ have a normal amount of color cells, the ones marked with ² a higher amount which are probably less used. ³ are monochrome modes. 320x200 NTSC was the most flexible resolution on the original Amiga. The later PAL models got 320x256. 320x240 is a quarter of VGA. The DOS version of Turrican II used this mode. D20 is the double resolution of the VIC-20. The VDC is well suitable for the VIC-20 color palette. QSVGA and QXGA would be named by PC resolutions, on the Amiga they are called Super72 and HighGfx. QXGA/HighGfx is also the double resolution of the ZX Spectrum. 512x342 is the resolution of the Mac ClassiC - To avoid confusions with Apple I think MCC is a better name. 640x400 Monochrome is the max resolution of the Atari ST and it would be the best resolution for GEOS 128.

@fradd182 7 ай бұрын

So, no way that one could make something like Elite for VDC? You just cant draw a line fast enough?

@idunproject 7 ай бұрын

I think it's possible. Just needs a lot of trickery. For example, rendering to local memory and generating character set tiles. Multiple character sets can be downloaded to the VDC, then used to draw pre-rendered images much quicker.