2021-11-26 22:41:51 +00:00
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# apple1-videocard-lib
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Library and demos for the Apple-1 TMS9918 video card by P-LAB.
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2021-12-16 10:05:26 +00:00
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# Building for the CodeTank/Juke-Box Expansion Cards
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2021-12-15 17:51:45 +00:00
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2021-12-16 10:05:26 +00:00
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The demo contained in the repo are meant to be launched from the Apple-1
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"CodeTank" EEPROM daughterboard of the "Apple-1 Graphic Card" or "Juke-Box
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Card" FLASH at address $4000. The executables are built according to the
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2021-12-15 17:51:45 +00:00
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following memory map:
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2021-12-16 10:05:26 +00:00
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$0000-$00FF zero page: holds most of C program variables
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$0280-$0FFF low RAM space: C program "Data" segment
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$4000-$7581 EEPROM/FLASH (CodeTank/Juke-Box): C program "Code" segment
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$7582-$7FFF EEPROM/FLASH (CodeTank/Juke-Box): C program "Data" segment (startup values)
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2021-12-15 17:51:45 +00:00
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2021-12-16 10:05:26 +00:00
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The build script `mkeprom.js` creates a 16K binary file to be placed on the
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EEPROM/FLASH where the "Data" segment startup values are put at the end of the
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file itself. The user program need to manually copy such data from EEPROM/FLASH
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to low RAM once after the `main()` is launched. This can be easily done by simply
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calling the library function `apple1_eprom_init()`.
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2021-12-15 17:51:45 +00:00
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