Dragon's Lair - if a ZX81 can do it, why not a QL?

[RWAP]

Well seeing the new demo of Dragon's Lair for the ZX81 (with an implementation of the game in the pipeline), I was wondering whether anyone fancies having a go at something similar for the QL, using the QL-SD or hard disk - see:

https://www.youtube.com/watch?v=V6-_48Aqso0

[ppe]

Hi Rich,

thanks for the pointer, looks rather impressive considering the HW platform

The nice thing about Dragon's Lair is that there really isn't much to the game logic. It all hinges on whether the player chooses the correct input (direction or attack if I recall correctly) within a pre-defined window of video frames. Depending on user's input, the game simply shows the relevant video. No sprites, movement, collision detection, etc. so the coding is centered mostly on how to make a smooth video player. I think there was a post on the forums from someone who showcased a video captured animation playing on the BBQL. This would indicate that if the video material and decision logic for Dragon's Lair is available somewhere it should be feasible to make a QL version. As you pointed out, you just need a fast-enough mass storage medium.

Cheers,
Petri

[Mr_Navigator]

Looking at the video it seems to range between 6 and 10 fps which is the bare minimum for computer animation, also bearing in mind there is no colour information required. That would need a lot of QL memory and processing speed. In simple terms and without any shortcut algorithms, at 6 fps = 32K*6 = 192K. However the actual animation on the ZX 81 is only about 1/4 of the screen, so again in simplistic QL terms that would equate roughly, at 6 fps = 8K*6 = 48K. Having said that, I spent a lot of money playing this in the arcades as it was, very much a new concept at the time and just loved playing the game.

[Derek_Stewart]

Hi,

Another way to do this would be to port the NES version, which the source code is available at:
https://tcrf.net/Notes:Dragon's_Lair_(NES)

The NES used 6502 CPU, so it would be portable to any platform, since we know the hardware differences of the NES and the QL.

If they had use PDS (Programmers Development System) which allowed cross compiling of software from PC to Z80, 6502 machines via hardware interfaces. This would be easier.

But the PDS hardware is very rare nowerdays, so I suppose it is doen toe hand porting the assembler code from 6502 to 68000.

No an easy job, but maybe doable?