Simple tutorial how NES graphics work

**fungusman** · 01-14-2012, 09:54 PM

Noob friendly explanation how NES graphics work. The nes only had 2k of video memory

https://www.youtube.com/watch?v=Hq4XT44YnPg

**Demon-Mask** · 01-15-2012, 03:30 AM

That's all pretty interesting.

**Seahawk** · 01-18-2012, 03:39 AM

The NES drawing function is more or less the same as all other game hardware of the era: Graphics are composed of 8x8 pixel tiles, you have 1 background, and up to 64 8x8 indenpendent moving objects, or sprites as you call them.

However, a nasty quirk on the NES is that the console only has 2KB of video memory, and that is reserved for 2 tilemap lists that are 1KB each.

For this reason, tile pattern definitions have to be stored on the cartridge, usually on a separate chip from the program data.

Because memory was expensive, the main bottleneck on NES development in the early days (1983-1985) was ROM chip sizes. This is why the very early NES games were little more than trash ports of single screen non scrolling arcade games.

As a cheap way to have more program storage, Nintendo made the disk system for Japan, which gave an additional 32KB of RAM to load programs into, as well as 8KB of VRAM that could be written to freely.

This problem was eventually solved with memory bank controllers which could map program and graphics data in and out of memory easily, as well as other fancy features like extra RAM, hardware multiply units, more sound channels, scanline counters, interrupt function, etc.

So the NES is unique in that most of it's strength comes from external accessories rather than the base hardware.

**warghoul** · 01-18-2012, 03:21 PM

Wow hawk you really know your stuff

**Demon-Mask** · 01-18-2012, 11:42 PM

Quote:

So the NES is unique in that most of it's strength comes from external accessories rather than the base hardware.

Isn't the SNES similar with all of it's specialized chips that made it capable of all kinds of things it wouldn't have been on its own?

**Seahawk** · 01-18-2012, 11:56 PM

Quote:

Originally Posted by Demon-Mask

Isn't the SNES similar with all of it's specialized chips that made it capable of all kinds of things it wouldn't have been on its own?

It's similar, but those chips are nowhere near as essential as they were on the NES.

The SNES chips (DSP series, Cx4, Super FX, SA-1, etc) were for specialized high end functions such as fast matrix math, 3D vector math, framebuffer effects, that pushed some games another level, but you could actually make competent SNES software without them.

On the NES, they were pretty much necessary for any game that wanted to be more advanced than Ice Climber, Balloon Fight, etc. basic early Famicom games.

I suppose I should add this.
Non-noob friendly NES tech sheet

**fungusman** · 01-19-2012, 01:45 AM

It's mind boggling how they made NES games. Not only did the system itself only have 80's hardware, think of the computers they had to use back then. The 286 wasn't even around. Just cold terminals to write 6502 ASM.

Devs are extremely spoiled now, that's a theory of mine why games suck these days. When Miyamoto, Carmack, Yu Sazuki, etc put out a game, you know it's going to be good.