Questions tagged [graphics]
For questions regarding graphical - as opposed to text - processing and display.
49
questions
25
votes
4
answers
6k
views
Z8410 DMA chip as GPU?
There are basically two ways to design a 2D graphics system:
Provide lots of hardware support in the form of tiles, hardware scrolling and sprites, to put together each frame on the fly from a small ...
- 58.4k
43
votes
4
answers
14k
views
Why did 80x25 become the text monitor standard?
Prior to the 1981 release of the IBM PC, the VT05 (72x20 1970), VT50 (80x12 1974), VT52 (80x24 1975), and VT100 (80x24 1978) text terminals were used on many Unix machines and the PDP-11 (probably the ...
- 1,339
32
votes
5
answers
5k
views
Does every retrocomputer and console with NTSC composite output have 'artifact color' ability?
Artifact color is heavily associated with the Apple ][, since that is the only method the machine had to produce a color display. I was looking at the fantastic demo for IBM PC + CGA, 8088MPH, and I ...
- 60.1k
40
votes
4
answers
9k
views
What determines the color of every 8th pixel on the Apple II?
On the Apple II there's an interesting way to add a little color to the bitmap, since the high bit selects the palette used for the three-and-a-half pixels represented by the byte. Like this:
0: Black,...
- 38.2k
28
votes
1
answer
32k
views
Why do 3D models on the PlayStation 1 “wobble” so much?
A memorable part of the PlayStation 1 experience was “wobbly” 3D graphics, where (supposedly) straight edges would warp, jitter and pulse as the camera panned across a scene. This was especially ...
- 1,079
22
votes
2
answers
1k
views
How do I use shadowed memory to render Super Hi-Res quickly?
The Apple IIgs video memory is controlled by the 1MHz Mega II chip, so directly accessing the Super Hi-Res page in bank $E1 is slower than accessing other memory. How can I render in "fast" memory, ...
- 8,775
22
votes
4
answers
7k
views
Why not one pixel per color clock?
Early home computers and game consoles output video to TV sets. The NTSC color clock frequency is 3.58 MHz. This informed the design of some video systems:
http://pineight.com/mw/index.php?title=...
- 58.4k
20
votes
2
answers
3k
views
How to check the C64 graphics mode used by Maniac Mansion
I have been investigating the MS-DOS port of the C64's Maniac Mansion game. The original MS-DOS port used the C64-specific character map to draw the various backgrounds in the game. I noticed that ...
user4411
20
votes
9
answers
10k
views
Can modern AI be used to program impressive graphics effects on very low performance home-retrocomputers, in particular 'A 3D-rotating-cube'
Can modern AI be used to program impressive graphics effects on very low performance home-retrocomputers, in particular 'A 3D-rotating-cube', effects that would be too difficult for a human to ...
- 379
19
votes
3
answers
4k
views
How do CGA emulators for Hercules graphics work?
HGC cards on IBM PCs used to be able to run CGA software by using a CGA emulator. How exactly did those programs work? What were the limitations?
- 1,274
17
votes
3
answers
2k
views
Ideal resolution for color computer on NTSC
Suppose you were, in the early eighties, designing a color computer to run on an NTSC TV with a free hand to choose the specifications within the limits of the technology of the time. What would be ...
- 58.4k
16
votes
2
answers
530
views
Inserting NOPs to improve IIgs shadow copy performance
The answer to this question discussed a technique on the Apple IIgs for copying memory onto itself. The motivation for the technique was to maximize use of "fast" (2.8MHz) RAM over "slow" (1MHz) RAM ...
- 8,775
16
votes
1
answer
4k
views
Why does the C64 have the following palette?
The Commodore 64 has the following fixed palette of 16 colours:
(Your palette may vary due to tuning of screen, etc.)
What was the reason for this selection of colours? Are these colours ...
- 161
15
votes
2
answers
2k
views
Why did the PlayStation 2 implement backward compatibility that way?
It is well known that the PlayStation 2 implemented compatibility with the previous console by essentially incorporating a PS1 on a chip.
The fact of backward compatibility is unremarkable as far as ...
- 58.4k
15
votes
4
answers
4k
views
For fast scrolling DOS games, when was Mode13h preferred over Mode X?
Back in the DOS days of gaming (more specifically, 80286 - 80486 era), developers typically needed to choose between using the chunky and easier Mode 13h or the more complex "Mode X" that provided ...
- 8,431
11
votes
4
answers
2k
views
What graphics sytems used display lists?
As near as I can tell, there seems to have been roughly speaking two schools of thought when it comes to graphics hardware among early consoles, what I will call the Atari and Texas Instruments ...
- 638
7
votes
2
answers
1k
views
How 3Dfx Voodoo 1 Emulator works
reading of this question brings up 3Dfx Voodoo 1 Emulator in my memories. I always wandered how did it work so good time as any to ask...
My memory is hazy on the details so I might miss remember ...
- 7,218
35
votes
1
answer
6k
views
How can I create a split-scroll effect in an NES game?
Games like Super Mario Bros. and Super Mario Bros. 3 were able to scroll the playfield but not the status bar:
The status bars are clearly too big to be sprites, yet they don't scroll with the ...
- 5,404
33
votes
1
answer
8k
views
Did John Carmack really invent "Adaptive Tile Refresh"?
John Carmack is credited with making fast-paced arcade games like Commander Keen possible on an IBM-PC that had no specialized graphics controllers suited for those, thanks to the "Adaptive Tile ...
- 1,109
31
votes
3
answers
4k
views
How did Elite do vertex transformation?
In 3D graphics, vertex transformation is the process of converting x,y,z coordinates in 3D space, to x,y coordinates on the screen. According to https://www.khronos.org/opengl/wiki/...
- 58.4k
28
votes
25
answers
4k
views
Which computers had redefinable character sets?
My first computer was an Exidy Sorcerer, bought in the late '70s. It featured a full keyboard including lower case, on screen text of 64 B&W characters by 30 rows, 2 MHz z-80 processor, up to 48 ...
- 8,663
27
votes
2
answers
3k
views
How to obtain 256 arbitrary colors with limitation of 64 per line in Amiga (ECS)?
The game Universe for Amiga boasted ability of use of 256 different Amiga colors available through the ECS chips, with only limitation of 64 colors in halfbrite palette (32 arbitrary + 32 at half ...
- 7,065
26
votes
7
answers
6k
views
How did DOS games manage to have multiple background layers?
Seems like VGA only has one background layer, it appears to be a typical bitmap screen like most home computers of the 80s (Amstrad CPC, Commodore 64 etc.) where each pixel's color is stored in a ...
- 1,638
26
votes
9
answers
3k
views
What implementations of BASIC had a robust flood fill operator?
When I learned BASIC on Elektronika BK, I got fascinated with the flood fill (PAINT) operator: how does it know to get to all nooks and crannies of the shape to fill? I've devised an algorithm, tried ...
- 18.3k
24
votes
6
answers
5k
views
What techniques were used to reduce the required re-rendering in 3D programs?
Inspired by this GameDev question.
3D rendering is expensive. With 2D games it's easy to not re-write the buffers every frame, like in Super Mario Bros where the PPU is instructed to render the level ...
- 18.5k
23
votes
2
answers
1k
views
What's a good way to implement this "splashing water" effect on the C64?
This pillow fighting game set in Venice
depicts the two opponents fighting on a wobbly gondola on a canal. It was apparently known as "Pillow Fight" in English and as "Kissenschlacht&...
- 38.2k
22
votes
5
answers
6k
views
Why were 3D games on the Amiga not faster than on similar 16 bit systems like the Atari ST
It seems that 3D games, especially simulations like Falcon, were not faster (fps) on the Amiga than on the Atari ST - even a bit slower due to the CPU clock.
I was wondering why this is the case, ...
- 1,387
21
votes
3
answers
4k
views
Typical dpi of dot matrix printers available in the 1980s
I have several printouts from what is presumably a dot-matrix printer, dated 1987. When zoomed in on these, you see the usual stair-step patterns on diagonal lines. However, it's difficult to ...
- 471
21
votes
2
answers
9k
views
Why do NES sprites flicker when there are a lot of them?
Sometimes, NES sprites flicker when there are a lot of them, like at 1:19 in this video of Super Mario Bros. Why did they do this?
- 5,404
20
votes
2
answers
1k
views
Fate of mystery Motorola RMS graphics chipset (68486 + 68487)
I recently learned that mid 1980s, Motorola was working on a discrete graphics chipset that would be a great leap forward from its 6847 Video Display Generator and 6845 display controller. It was ...
19
votes
3
answers
2k
views
Can a Commodore 64 use two screen modes on one scanline?
Many games, for example, Maniac Mansion, or Kissenschlacht, use two screen modes. Oftentimes, a bitmap mode for the main screen, and a text mode for the lower part which displays scores or whatever. ...
- 38.2k
18
votes
1
answer
4k
views
Where did Sony's 3D graphics hardware in the PS1 originate?
As is well-documented, the Fifth Generation of game consoles brought 3D accelerated graphics hardware to the home market. The main combatants in this particular console war of the mid-1990s were the ...
- 60.1k
14
votes
7
answers
4k
views
Were there any "off the shelf" graphics chips that supported 2D sprites in the 70's and 80's?
I'm looking for "off the shelf" graphic IC's that supported hardware sprites. By "off the shelf" I mean chips that were designed to be used in various machines and not designed specifically for one ...
- 8,431
14
votes
1
answer
1k
views
What was the change to the Apple //e motherboard that allowed for Double HiRes graphics?
Double Hi-Res graphics (DHGR) was a nice addition to the Apple ][ line as it allowed for higher resolution 560x192 graphics with 16 colors in comparison to the traditional 280x192 with 6 colors. It ...
- 15.8k
14
votes
2
answers
2k
views
What is the size of the border of the ZX Spectrum in scanlines/pixels/bytes?
The bitmap area of the Sinclair ZX Spectrum is exactly 256 x 192 pixels.
Surrounding the bitmap is quite a wide border area which is generally just one colour but loading and saving from tape changes ...
- 6,333
13
votes
3
answers
3k
views
What DOS games used Mode X as described by Michael Abrash?
In Michael Abrash's Graphics Programming Black Book, many chapters are dedicated to fast drawing of primitives, fills and copies using the 320x240 256-colour Mode X.
What MS-DOS games used Mode X?
...
- 353
13
votes
1
answer
211
views
Videoprocessor with custom horizontal sampling
I have a variety of videoprocessors (Micomsoft Framemeister, Micomsoft SC-512N1-L/DVI, Sync Strike) to help me get the best possible RGB picture out of my retro computers/consoles.
However one issue ...
- 1,079
12
votes
8
answers
3k
views
What are principles of vector CRT display? Simplest way to drive CRTs? [closed]
I am into playing with TTL to build 1970s style minicomputers. Aside from talking to them via some serial (or parallel) I/O port to a terminal, I am wondering about display output. This here is about ...
- 1,377
12
votes
2
answers
3k
views
How does Atari 2600 TIA display multiple resolutions in Asteroids?
There is probably an easy explanation for this based on some facet of how the TIA generates the display. As is readily visible in the image taken from a real Atari 2600 displayed on a modern LCD, the ...
- 60.1k
11
votes
4
answers
3k
views
Actual resolution of composite video monitors
Many early computers used TV sets as monitors. With an NTSC TV set, you could really only count on about 200 scan lines of vertical resolution, and for horizontal resolution, maybe 192 color clocks at ...
- 58.4k
10
votes
2
answers
2k
views
NTSC scan lines and vertical resolution
From https://en.wikipedia.org/wiki/BBC_Micro "the height of the graphics display was reduced to 200 scan lines to suit NTSC TVs". But NTSC is supposed to have 241 visible scan lines per half frame. ...
- 58.4k
10
votes
1
answer
354
views
What is the timeline of vertical cursor usage?
As there have been some questions about vertical cursors:
What is the timeline of vertical cursor usage?
This includes anything that is positioned between characters. It doesn't have to be a vertical ...
- 26k
10
votes
2
answers
1k
views
What PC graphics tech outperformed Sega Dreamcast in 1999?
The Sega Dreamcast was released in 1999 (1998 in Japan) at just the time that the competition for 3D graphics on PCs was intensifying. It's my assumption that a high-end 1999 Pentium II PC with 3Dfx ...
- 60.1k
10
votes
1
answer
2k
views
How did the Rush 3D engine in Crazy Taxi: Catch a Ride work?
In an interview with the developers of the Crazy Taxi game for the GBA, they mention that they were able to achieve 3D graphics with a pure-software 3D rendering engine that they called Rush:
It is a ...
- 1,999
9
votes
2
answers
2k
views
Were any DOS games (or software) known to use VBE/AF?
Were there any MS-DOS games or graphics software that were known to take advantage of VESA BIOS Extensions/Accelerator Functions (VBE/AF)?
some of the functions defined in the standard are ... Bit ...
- 2,102
7
votes
1
answer
284
views
Was there an Evans & Sutherland display system capable of rendering ordinary data as motion through a landscape?
Around 1987, the investment bank I worked for had a high-end graphics device, possibly from Evans & Sutherland, which produced an "animated" display not unlike the view from the front ...
- 79
7
votes
2
answers
3k
views
What was the dithering algorithm used in Sierra and LucasArts games?
I am trying to write a program in C# that will re-create the type of dithering used in many of the old Sierra and LucasArts games. I have looked up many different dithering algorithms and none seem to ...
- 171
6
votes
2
answers
2k
views
How to exactly sync to the raster line for a vertical raster split?
Motivated by Wilson's question Can a Commodore 64 use two screenmodes on one scanline? I tried to implement a simple example that polls the beginning of a rasterline and then switches the screen mode ...
- 4,437
1
vote
0
answers
490
views
Thinking through the design of a TTL video card: what memory chips and how to manage memory? [closed]
Inspired by Ben Eater's "Let's build a video card" aka "World's worst video card" two part projects on YouTube, I was inspired to consider designing a display adapter for my passive backplane TTL mini-...
- 1,377