ham_convert 1.9.4

New in this version: Acorn Archimedes VIDC1 256-color mode, Dynamic Hires with an AGA palette, PCHGF_32BIT ILBM IFF format supporting 8-bit per channel palette changes, extra OCS palette optimization.

Main mirror (all stable and testing versions)
External mirror


  • Added DynamicHires variant with an AGA palette. To enable select mode=Amiga AGA Dynamic HiRes/PCHG software mode.
  • Implemented PCHGF_32BIT format to be used by DynamicHires AGA and Atari 8-bit ILBM IFF files (using BigLineChanges). DynamicHires OCS uses PCHGF_4BIT (SmallLineChanges) format IFF limited to RGB444. https://wiki.amigaos.net/wiki/ILBM_IFF_Interleaved_Bitmap#ILBM.PCHG and PCHG.guide from http://aminet.net/package/dev/misc/PCHGLib14 were used as a reference. This enabled accurate encoding of the Atari 8-bit palette in the iff files.
  • Extra EHB palette optimization was renamed extra OCS palette optimization and extended to support also 2/4/8/16/32-color modes (to be extended later).
  • Acorn Archimedes VIDC1 256-color mode (out of 4096). 256-color mode is implemented using only 16 color registers producing a very limited and user-unfriendly method of defining color palette. It’s a bit like Half-Brite. Modified Extra EHB palette optimization is used to generate palette. User can only define lower bits of each channel, for a total of 8 bits out of 12. Higher bits (4 total) are filled by the video chip. Each of the 16 color registers will define 16 colors with the same 8 bits defined by the user and different remaining 4 bits defined by the hardware (all combinations of these 4 bits will be generated). Selecting palette source=fixed will use this mode’s default palette with mostly saturated colors. Below is this mode’s bit encoding by IanJeffray from stardot.org.uk:

    Acorn Archimedes VIDC1 256-color mode encoding

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