2600 to Atari 8-bit conversion

[SmileyDude]

i think there was a thread on the 8-bit board about some games that looked as though they were just ported from the 2600 to the 8-bit without any changes. That got me thinking -- how hard would it be to "port" a game in that manner? Is there a list someplace of 2600 registers and where they are in the 8-bit?

 

Just curious, thought it would be kinda neat to see

[Dr. Van Thorp]

The two machines have very differenct internal workings. You could port the game, and keep the look of the original graphics, but the part of the software that displays those graphics would be very different.

[Wrathchild]

I was doing something like this with Combat, however

I would say that a direct port of say a games kernel

(primarily the screen drawing part) is not always feasible

and you better off mapping the ideas of a game to the

A8 specific ways of doing something.

 

Examples of problems are:

2600 supports playfield reflection, this can be done

in the vertical though custom Dlists, but in the

horizontal this means you need to write this in software

to compensate. Not always used though in 2600 games.

2600 sprites can be flipped and also 'cloned' (e.g. the planes

in combat) by hardware. Although the expansion of a sprite

is similar, this means you need to use some of the other A8

players and missiles to provide this... more overhead.

Therefore you end up doing the sprite graphic prepartion work

when screen drawing is outside of the display areas (e.g. VBI)

rather than on-the-fly as a 2600 game typically does.

2600 sound - slightly different random generators used for

the noise, but doesn't look too tricky to translate this.

[DanBoris]

When developing my 5200 emulator I discovered that Activision actually did this to some extent on Kaboom (and maybe others). On the 2600 sprite data is written to the TIA line by line. On the 5200 this is handled automatically by the ANTIC chip via DMA, but the registers to directly write the data are still there and Kaboom uses them instead of the DMA.

 

Dan

[Dr. Van Thorp]

On the 2600 sprite data is written to the TIA line by line. On the 5200 this is handled automatically by the ANTIC chip via DMA, but the registers to directly write the data are still there and Kaboom uses them instead of the DMA.

 

I'm amazed that someone would use this primitive feature when something so much more advanced and easier was available.

 

Was this also available on the 8-bit computers? I allways thought that they had the same graphics hardware as the 5200.

[bjk7382]

Here is the thread that I started on the 8-bit forum.

 

If you look at the superman game it looks like a 1:1 conversion.