[Coco] Tandy Electronics??!!

[Nick Marentes]

On 2/01/2015 2:09 PM, Bill Loguidice wrote:
> I know you can't effectively compare the resolution of a vector display to
> that of a raster display, but it seems to me that even disregarding the
> whole apples to oranges thing, how can the CoCo 3 emulate the Vectrex
> correctly when the Vectrex effectively has a higher resolution?
>
> (By the way, I'm a huge Vectrex fan and have a large collection of items
> related to it; versus almost all other vintage hardware, thanks to the
> Vectrex's unique display, it's arguably one of the few vintage videogame or
> computer systems that genuinely requires the original hardware (versus any
> type of emulation) for the "proper" experience.)
>
> -Bill
>
>

Same way John made Donkey Kong, which has a higher vertical resolution, 
made it fit onto the CoCo.

Because you are writing an emulation of the video hardware, you can 
provide rescaling in that area. The original code thinks it's writing to 
the full resolution but you hardware emulation software reinterpretes it 
differently.

I think if anyone knows if it can be done, John would be the man. He 
actually did describe an algorithym for doing this to me. I won't repeat 
it because that's his algorithym.

The big challenge, as it was with Donkey Kong, is creating the code so 
that the Vectre emulation is the same speed or at least close to. 
Remember, we're talking monochrome here so no color needs to be 
processed. This may also mean that a 640 x 225 x 2 (18K) resolution 
would be the CoCo3 resolution to emulate the vecter display.

The Vectrex resolution is apparently 340 x 410.

The CoCo3 comes close except for the fact that the Vectrex display is 
vertical (short side at the top, long side on the sides). This provides 
the biggest challenge still a possibility to scale. Worst case, rotate 
the CoCo monitor (Donkey Kong needed rotating to)!   :)

Nick