ham_convert 0.7

A new version with a few new features and fixes is ready.

ham_convert 0.7

ham_convert 0.7

Get it here:
Mirror (all versions)

Here’s a list of changes:

  • Amiga HAM modes: Color hack now uses a new color error formula (3xred+4xgreen+2xblue). It produces better results with well calculated base palettes. The old one (2xred+3xgreen+1xblue) was useful in the first versions when there was no way to use a better base palette than a crappy 6-bit RGB. With better palettes the blue component appeared washed too much.
  • Added the VGA fakemode (fake 18-bit mode) used around 1995 in scene demos to create a illusion of more than 256 colors at once on a standard VGA card. It was explained in the earlier post.
  • Added the experimental (and very slow) C64 hires modes. There are 2-color and 4-color per 8×8, 8×1 or 8×2 block variants. 2-color modes were developed by modifying earlier ZX modes. They simulate C64 hires and (partially) fli modes. 4-color modes use any 3 colors out of 16 and a background color shared among the screen (like lores multicolor C64 modes). The background color is 50% gray. I will add background color selection in the future. 4-color modes are partially based on software C64 modes like nufli. It’s an early version and it will be improved to fully match various C64 software modes. The C16/Plus4 modes are also in development due to their big 121-color palette.
  • A few speed optimisations.

Some test pictures (Koszalin, Poland, 54°12’08.8″N 16°11’40.6″E):

Base image (Koszalin)

Original image (Koszalin, Poland – Wańkowicza street, view from the 10th floor)

VGA fakemode

VGA fakemode (fake 18-bit hicolor)

64-color EHB mode (Amiga OCS/ECS)

64-color EHB mode (Amiga OCS/ECS)

HAM6 mode (Amiga OCS/ECS)

4096-color HAM6 mode (Amiga OCS/ECS)

C64 2-colors per 8x8 block mode

2 colors out of 16 per 8×8 block (C64 hires mode)

C64 2-colors per 8x1 block mode

2 colors out of 16 per 8×1 block (C64 hires fli mode)

C64 4 colors per 8x8 block mode

4 colors out of 16 per 8×8 block (C64 hires software mode)

C64 4 colors per 8x2 block mode

4 colors out of 16 per 8×2 block (C64 software mode)

Unfinished modes:

16 colors every line out of 4096 (Apple IIGS)

16 colors out of 4096 every line (Apple IIGS, software mode on the Atari STE and the Amiga-Dynamic Hi-Res)

2 colors per 8x2 block out of 121 (Commodore Plus4 hires fli mode)

2 colors out of 121 per 8×2 block (Commodore Plus/4 hires fli mode)

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