Hot answers tagged

25

There's something of a conflation here of antialiasing and filtering, I think. Antialiasing is literally preventing things from adopting aliases — e.g. if a diagonal line looks like a staircase rather than a diagonal line, it has adopted an alias. So you can imagine the same thing happening to textures as they rotate or take awkward angles. But it's always ...


19

The NES did not use an extra bit for sprite positions. A sprite's X-position was the position of its left edge, which means that sprites cannot be placed partially off the left side of the screen: However, the NES did actually provide the feature you're suggesting, in a way: bits 1 and 2 of the PPUMASK register can be used to keep the leftmost 8 pixels of ...


13

On paper, based on the fill rate only, all the high-end graphics adapters available on PC in 1999 were at least as powerful as the Dreamcast’s PowerVR2: the CLX2 in the Dreamcast ran at 100MHz, with one operation/pixel/texture per clock, and memory bandwidth of 0.8GB/s; the PMX1 (PC-compatible PowerVR2) ran at 125MHz, again with one operation per clock, and ...


11

The first generation of consoles use proprietary APIs; I can speak directly as to the PS1. In the PS1's case there's a vector coprocessor for performing 3d transformations and one is subsequently responsible for compiling and supplying list of triangles in direct screen coordinates for drawing. Usually calculated via the vector coprocessor, but it's up to ...


11

The price difference was indeed entirely in the packaging. The important thing to remember about mask ROMs is that, though the setup costs and lead times were high, they had the lowest marginal cost of any form of memory. The reasons behind this are fairly clear if you look through this ROM, EPROM, & EEPROM Technology document from Integrated Circuit ...


10

[not a complete answer, but some remarks too big for a comment] [also it focuses on games, as they are the most complex, real time application. Antialiasing for desktop UI and editors are a fairly insensitive issue and a subset thereof] Need for Colours A point, often forgotten from today's view is that antialiasing does need a video system systems with fine ...


10

They have different memory and IO maps. The ColecoVision has a boot ROM at address 0000h and an inserted cartridge appears at 8000h. The Sega has no boot ROM so just maps the inserted cartridge at 0000h. RAM is at C000h on the Sega, 6000h on the Coleco. The Coleco's TMS is addressable between ports 40h and 7fh (including mirroring) but the Sega's is at BE ...


9

Accident analysis includes the concept of the chain of events. The fundamental premise being that there's not usually just one mistake that leads to an accident. It usually takes several, and sometimes many mistakes, before an accident finally occurs. Likewise, it's oversimplistic to say that a game console failed solely because of one factor. The failure of ...


9

Here is an unofficial port to the Amiga, known as "Heart of the alien Redux". To my knowledge it uses the original engine with the data of the SegaCD version. No idea how much work there was required to make it actually work, but I presume that the Sega CD engine is not that much different from the Amiga engine. http://www.indieretronews.com/2016/...


7

Those companies did implement their own graphics APIs that were very light weight and didn't have too much complex functionality. This was done because their libraries could be tailored to the strengths or weaknesses of their system. They also had very unique architectures that took different approaches to producing 3D graphics. Later on, consoles and PC ...


7

TL;DR: If I connect it other way would any components blow? No. Let's have a look at the circuitry All following schematics are taken from the 1993 manual. To start with, the wall wart is delivering 9..10V (depending on region *1) DC. (Page 7 lower right corner, B6/B7) Polarity is not mentioned at all - not here nor in any other overview or part list. ...


6

This was in no way part of a hardware assisted 3D pipeline, but there were attempts made in PC-class hardware to achieve anti-aliasing even as early as 1990. Edsun Labs made a drop in replacement RAMDAC for VGA boards that used some of the 256 possible color values as opcodes that would enable color blending between pixels on a line. This let a nominally ...


5

If the author's quote found on the Wiki page is accurate it seems the answer is "no", depending on various readings of the terms: neither the animations nor the game, entirely developed by Interplay, were up to the job "Entirely developed by Interplay" can mean different things. If we take the statements at face value, it means "...


4

256 is the maximum number of pixels per row, but most games used fewer. Using fewer pixels allowed for partially off-screen sprites with only 8 bits of position information. Most hardware of that era allowed some flexibility with screen resolutions. While the timing for the display (PAL or NTSC) was fairly well nailed down, the programmer could choose to ...


4

According to this website, https://segaretro.org/Tomb_Raider "The European Saturn version also have minor differences to level layouts (specifically some secret areas) because it was rushed to launch three months before the PlayStation version. This was fixed in the North American and Japanese versions." Maybe these differences are what you ...


3

I heard "on the grapevine" that Sega, with their benchmarks, felt CLX2 outperformed the PC parts of that era. Although CLX2 'only' had peak texture & shading fill rate of 100Mp/s, it performed rasterisation and hidden surface removal at a peak rate 32x higher, i.e. 3.2Gp/s. Thus for 3D worlds where there is nearly always a reasonable amount of ...


3

the stuff you are describing has nothing to do with x resolution selection. In the 8 bit era CPUs didn't have mul , div instructions so computing *,/ was really expensive. That is why the x resolution is usually power of 2. That allows to compute pixel address from x,y coordinates using just basic ALU operations. For example on 256 pixels per line and 1 ...


3

But the first systems didn't run an OS like that? Well, they did, some kind of proprietary OS. So how graphics were programmed to these machines? Using functions of said OS, or bare bone. Did the companies developed and implemented their own graphics APIs (like OpenGL)? Exactly. Just usually a lot less advanced than that. It might be useful to keep ...


3

Furthermore, (correct me if I'm wrong) the Commodore Amiga can also read a joystick button wired this way being pushed, as although it treats pin 9 as an analog input, the Amiga's analog pins are active low. All the "early" Atari-derived systems read pins 5 and 9 as analog. There may be later designs, like MSX, that work differently, but the Atari, C64 and ...


3

The video circuitry was a lot simpler in those days and there was no true GPU as we have today. The video memory was part of the CPU memory space and any video circuitry merely converted it into a video signal. There was no graphics processing outside of what the CPU did. Some, particularly earlier systems use discrete components to produce a simple video ...


2

Based upon a quick look at the PAL Megadrive II schematics, it appears as if the the power input is first routed through a common mode choke(for which polarity does not matter) before it goes onto the power switch. After the power switch, it is routed through a reverse polarity protection diode before it is fed to the input of a LM7805 regulator to provide ...


2

Broadly speaking, all these systems worked in the same way. The base system is always the same, generate the lines and synchronisation pulses needed to build display frames. The video circuit (could be a single chip or not) knows when it starts a single frame, and has somewhere access to memory (which can be private or shared with the microprocessor). It ...


2

A standalone processor, such as the ones you have listed, would usually only be able to perform some basic operations on integer data. This would typically be add and subtract because those operations can be trivially implemented with minimal amounts of logic (see Ben Eater's series on building a CPU on a breadboard as an example). Earlier versions of the ...


1

Not really an answer, but... ...The phrase "co-processor," can mean two different things. When you're talking about a "floating point co-processor" or "FPU," you're probably talking about a chip that extends the capabilities of the main CPU. In a very real sense, it becomes part of the CPU when it is installed. It adds ...


1

I believe it's because there's an alternative preservation hashing project named Redump that focuses on optical media. Since No-Intro focuses on cartridge games, it would be duplicated (though not wasted) effort for both projects to spend time on the Saturn. On No-Intro's website: Welcome to the No-Intro wiki! We specialize in video game preservation for ...


1

In addition to the above explanations re: sprites actually only having 8 bits of position resolution, the first column blanking option etc, the NES - and others following its same general design - actually had another, simpler, more physical tactic to address the problem: Overscan. The pixel generator clock, derived from the NTSC colourburst crystal by some ...


1

According the the German Wiki there was no game successor but a rather rare fan-manga called "Landstalker 2 - Heart of Diamond". Maybe thats where your memory is based on? There where several games based on the same engine/principles on other systems, but no direct follow up. Another candidate may be a revival in 2006, called "Landstalker 3D", for the ...


Only top voted, non community-wiki answers of a minimum length are eligible