Short: Custom Amiga screen mode generator Author: simon@studio.woden.com (Simon N Goodwin) Uploader: simon studio woden com (Simon N Goodwin) Type: dev/misc Version: 1.0 Architecture: m68k-amigaos CharMode shows how the Amiga graphics hardware can generate grid-based graphics modes with animated fonts and automatic rendering from a byte code to patterns on screen without any CPU overhead! It uses the Copper to program the Blitter to program the Copper to program the Blitter so that one write to a chipRAM buffer can update a whole pattern rectangle on the screen, or all patterns corresponding to a certain code - and all the work is done by the custom chips. Once they have been set up, with a highly configurable Copper List Compiler, character and font/pattern updates are completely automatic, beam-synchronised (so no update jaggies :-) at the full speed of the TV display, e.g. 50/60 fields per second. Examples of character-mapped modes that emulate PC MDA, CP/M, PET, MSX, Memotech, Sinclair ZX-80/81, Dragon, TRS-80 and many other classic character-mapped computers are included. While the technique is very useful for computer emulation (and was actually implemented in Amiga Qdos) it could also be useful in many other applications where a large display needs to be updated with a very small CPU load - such as terminal and teletext software, and many sorts of demos. It's also a good demonstration of the power of the Amiga custom chip set, and was first published as the finale of the author's Amiga Format 'Banging The Metal' series in March and April 2000. The archive includes graphics, programs and sample output, published and unpublished documentation in text, HTML and the original formatted Final Writer/Final Copy format, and source code in SuperBASIC suitable for any Amiga, with installation instructions. Requirements An Amiga or emulator with full custom chip support (OCS/ECS/AGA), See also these files on Aminet: util/moni/CopperDecode.lha - Copper list disassembler from part 5 of the AF series, used to generate these example listings. misc/emu/Qdos4Amiga1.lha - Qdos operating system emulator (source and support files in same directory, Qdos4Amiga and 3) used to develop the Copper List Compiler without AmigaOS getting in the way! Status This is a much expanded version of the programs and text in the last two parts of my Amiga Format series Banging The Metal, which appeared in issue 134 and 135 of the magazine last year (2000). This is the culmination of more than five years work, starting in 1996. Some of the programs and text written to accompany this series appear on Aminet by agreement of the copyright holders: author Simon N Goodwin and the purchaser of first UK publication rights, Future Publishing. The files listed below are copyright but may be freely copied by individuals if kept together, strictly and only for private use. You are required to contact the author simon@studio.woden.com for permission before publishing edited or derived works, but in general you are encouraged to do so.