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articles:iicplus_merlin [2017/12/14 15:11] M.G. [Fixing ROM 5X] |
articles:iicplus_merlin [2017/12/14 15:18] M.G. [Conclusion] |
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| </code> | </code> | ||
| - | We make use of the IIc Plus's existing routines to save and restore the language card state, and in between we call the ROM 5X dispatch, which executes the classic "air raid beep" that the Apple II line is known for. | + | We make use of the IIc Plus's existing routines to save and restore the language card state, and in between we call the ROM 5X dispatch, which executes the classic "air raid beep" that the Apple II line is known for. In fact, this can be used to call any of the ROM 5X functions, now or in the future, and preserve the RAM state, provided we don't care about the contents of the A register. |
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| There are plenty of programs that copy the ROM into RAM in order to modify it or make use of the routines in a non-standard memory configuration. That's what's going on here. | There are plenty of programs that copy the ROM into RAM in order to modify it or make use of the routines in a non-standard memory configuration. That's what's going on here. | ||
| - | Apple probably hit this problem early on in testing, perhaps noting an odd crash in a popular assembler. | + | Apple's engineers probably hit this problem early on in testing the IIc Plus, perhaps noting an odd crash in a popular assembler. |