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apple1-videocard-lib
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apple1-videocard-lib

Library and demos for the Apple-1 TMS9918 video card by P-LAB.

Building for the CodeTank/Juke-Box Expansion Cards

The demo contained in the repo are meant to be launched from the Apple-1 "CodeTank" EEPROM daughterboard of the "Apple-1 Graphic Card" or "Juke-Box Card" FLASH at address $4000. The executables are built according to the following memory map:

$0000-$00FF zero page: holds most of C program variables $0280-$0FFF low RAM space: C program "Data" segment $4000-$7581 EEPROM/FLASH (CodeTank/Juke-Box): C program "Code" segment $7582-$7FFF EEPROM/FLASH (CodeTank/Juke-Box): C program "Data" segment (startup values)

The build script mkeprom.js creates a 16K binary file to be placed on the EEPROM/FLASH where the "Data" segment startup values are put at the end of the file itself. The user program need to manually copy such data from EEPROM/FLASH to low RAM once after the main() is launched. This can be easily done by simply calling the library function apple1_eprom_init().