What's new

Clearpaper

Student
Joined
May 22, 2019
Messages
17
Reaction score
29
Location
Singapore
As with all video signals designed during CRT days, an overscan area was required and often we do not see the top-, bottom-, left- and right-most pixels of an original signal.

The Neo Geo has the ability to output a maximum horizontal resolution of 320 pixels.

Quite a number of games have a reduced visible screen width of 304 pixels (8 pixels on each side removed).

Interestingly, for some, the full graphics are still rendered there, however, they are intentionally overlaid with a black FIX layer.
(this was a practice so much so that there are default subroutines in the BIOS to do so)

On modern flatscreen displays, however, we can see these pixels clearly.

Pulstar's typical viewable gameplay screens are 304 pixels wide. I took a look and found the subroutines that perform this 'blacking', and these are the results of bypassing them.

Stage-1.gif

Stage-2.gif

Stage-3.gif


The mod is conveniently a simple 1 byte change at $364F8 from 1E to 64 (in Pulstar's P1).

Makes quite a visual difference.

Stages collage.jpg


Note, however, that the movement boundaries for your ship is still within the original 304-pixel space. I'd very much like to see someone with better debugging skills than I attempt to remove this limit.

And if it's not too much to ask, resolve the slow down issue and the weird screen transitioning flicker. :P
------------------------------------------------------------------------------------
IPS
 
Last edited:
Back
Top