Commander X16

On 8/11/2020 at 4:47 PM, AndyMt said:

The background is 8bpp in 320x240.

I had no idea you could create different screen resolutions other the ones provided by the SCREEN command, i.e. mode $80 320x200x256 and $81 640x480x16!

Use some POKEs in the vscale and hscale registers of Vera. Both set to 64 gives you 320x240 . The depth is not dependent ... can be anything that fits into screenram.

1 hour ago, SerErris said:

Use some POKEs in the vscale and hscale registers of Vera. Both set to 64 gives you 320x240 . The depth is not dependent ... can be anything that fits into screenram.

So, (monochrome SVGA) 800x600x1bpp = (800 pixels / 8 pixels-per-byte) * 600 lines = 60,000 bytes is possible?

Also, (monochrome XGA) 1024x768x1bpp = 98,304 bytes?

Also, (monochrome WXGA+) 1280x800x1bpp = 128,000 bytes?

46 minutes ago, geek504 said:

So, (monochrome SVGA) 800x600x1bpp = (800 pixels / 8 pixels-per-byte) * 600 lines = 60,000 bytes is possible?



Also, (monochrome XGA) 1024x768x1bpp = 98,304 bytes?



Also, (monochrome WXGA+) 1280x800x1bpp = 128,000 bytes?

No, have a look here: https://github.com/commanderx16/x16-docs/blob/master/VERA Programmer's Reference.md

The VERA does a fixed resolution of 640x480@60Hz, smaller resolutions are actually done via scaling.

lol .. @Fnord42 is right .. max is by all means 640x480. but other than that you are pretty free to play around with the scalings .. 

8 hours ago, Fnord42 said:

No, have a look here: https://github.com/commanderx16/x16-docs/blob/master/VERA Programmer's Reference.md

The VERA does a fixed resolution of 640x480@60Hz, smaller resolutions are actually done via scaling.

To be clear, is that one scaling parameter, or is it a choice of (640,320)x(480,240) logical bitmaps with an additional scaling to what part of the logical bitmap is shown on the screen?

All I need right now is the "old KERNAL" call to the number of characters per row in the screen mode, so my "SuperCPU C64" emulator and x16emu displays both work correctly from the same binary, but eventually I am sure there is going to be a demand for output to the proportional character display w/embedded bitmaps, a la GeoForth.

No it is actually two parameters, and they can work idependently.

So you can set hscale to 64 and get 320 and vscale to 52 (as far as I remember from my old brain) and that gives you 200... So you have a resolution of 320x200. So you can scale to any value. I have not tried myself what happens if you scale to anything between 64 and 52 ... 



Regarding the number of characters per Row... that is also affected by vscale and hscale.. 

128 for hscale equals 80 characters. Where 64 equals 40 characters and so on... 16 would equal 10 characters ? 



AFAIK (not 100% sure) you can only scale the whole VERA. That means, you cannot scale the two layers with differenet scaling parameters.

Just to be clear though, in "screen 128" mode, it's scaled to 320x240, but then the bottom border is made bigger, so it cuts off the bottom 40 pixels.  If it was scaled to 320x200 it would probably look a little squished, hence having the black border on the bottom.

New Version 0.4:

Some gameplay changes:

• 
  Level is lost when bottom enemy progresses to shields/fortress.
  
  You then fall back to the previous level and can try to advance again.
  


• 
  If you fail level 1, then the game is over, too (or all lives lost).
  


• 
  Enemy movements get more difficult with each level.
  
  They move faster, they advance faster. Patterns still the same
  


• 
  Player sprite now has more realistic lag, when changing direction.
  
  Let me know what you think about this one. It was just unrealistically fast with the mouse, so I made it more difficult.
  

Other improvements:

• 
  More Levels!
  
  The background story is now more complete. The descriptions for levels > 2 don't yet match the description in relation to enemy behavior or motherships etc.
  


• 
  Different enemy sprites
  
  I experiment with different enemy styles now. Most will probably be replaces later again. I like the martians, though ?...  
  


• 
  Sprite animation for player sprite
  
  Player spaceship now shows thruster plumes and tilts when moving.
  

Forgot to mention some cheat-codes in this version ?:

'L': jump to next level

'R': return to previous level