Questions tagged [graphics]

For questions regarding graphical - as opposed to text - processing and display.

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23
votes
4answers
5k 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 ...
30
votes
5answers
3k 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 ...
20
votes
9answers
9k 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 ...
34
votes
3answers
9k views

Why did 80×25 become the text monitor standard?

Prior to the 1981 release of the IBM PC, the VT105 (72×20 1971), VT52 (80×12 1974), and VT100 (80×25 1978) text terminals were used on many Unix machines and the PDP-11 (probably the most widely used ...
36
votes
4answers
7k 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 select the palette used for the three-and-a-half pixels represented by the byte. Like this: 0: Black,...
24
votes
1answer
18k 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 ...
21
votes
2answers
788 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, ...
20
votes
2answers
2k 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 ...
14
votes
4answers
2k 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 ...
11
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4answers
1k 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 ...
9
votes
5answers
4k views

How can I adapt a digital CGA/C128 signal (RGBI DE-9) to a modern monitor?

IBM's CGA and the Commodore 128's RGB video output both use a DE-9 connector. How do I adapt the CGA video output from an IBM XT 5160 or Commodore 128 to a modern monitor?
29
votes
1answer
4k 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 ...
23
votes
6answers
4k 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 ...
13
votes
7answers
3k 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 ...
31
votes
3answers
3k 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/...
27
votes
2answers
2k 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 ...
20
votes
3answers
3k 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 ...
15
votes
1answer
2k 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 ...
9
votes
7answers
2k views

What are principles of vector CRT display? Simplest way to drive CRTs?

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 ...
21
votes
2answers
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&...
13
votes
1answer
2k 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 ...
18
votes
3answers
3k 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?
12
votes
2answers
1k 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 ...
19
votes
4answers
6k 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=...
14
votes
1answer
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 ...
10
votes
4answers
2k 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 ...
7
votes
1answer
858 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 ...
1
vote
0answers
213 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-...
22
votes
5answers
5k 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, ...
15
votes
2answers
893 views

Can a Commodore 64 use two screenmodes on one scanline?

Many games, for example, Maniac Mansion, or Kissenschlacht, use two screenmodes. Oftentimes, a bitmap mode for the main screen, and a text mode for the lower part which displays scores or whatever. ...
14
votes
1answer
261 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 ...
13
votes
1answer
177 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 ...
6
votes
2answers
918 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 ...