36 lines
1.4 KiB
Markdown
36 lines
1.4 KiB
Markdown
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# Running the demo
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I would make a snarky comment about trivial exercises left up to the reader,
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but that would be evil. Don't do this, don't be evil.
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I am not great at assembly, or configuring my linker (ld65), and this is not
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a single, self-contained binary.
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To view the complete effect, htimg.bin must be loaded into three places in
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memory using BLOAD.
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```
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BLOAD HTIMG.BIN,$A2000
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BLOAD HTIMG.BIN,A$4004
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BLOAD HTIMG.BIN,A$6000
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BRUN DEMO.BIN
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```
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The graphics data at $6000 is a cache for real-time effects. The memory
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addresses $2000 and $4000 are the high-res graphics mode page 1 and page 2
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buffers. The data is loaded into $4004 to fix a byte offset error. This is
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intended, because, the same data loaded into $2000 causes an intentional
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rendering issue.
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If I had spent more time using the indirect indexed addressing mode in more
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places I could minimize this to a single BLOAD, but I haven't improved it in
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this way yet. If anyone can help me configure ld65 to include the $2000 bytes
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of graphics data directly in the executable, I would be very grateful.
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AppleDOS throws I/O errors when I have tried.
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I'll upload the binaries as well, in case people don't want to assemble their
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own. I ran this on the Virtual ][ emulator, although I needed to configure the
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file as "binary, strip prefix $8000" for it to run properly. Your emulator may
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not have this feature, it hasn't been tested on real hardware, and this may
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be a quirk of me not knowing what I'm doing. :)
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