[atari7800] [RE]direct indirect headers

> This would seem to imply...that you can use a 5-byte header for direct
> mode?
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Yes, you can use direct mode in a 5-byte header. Those type of headers aren't only for indirect mode - that's just the most common application. Another application for 5-byte headers is to set the Write Mode - which must at least be done at startup in your first header.


> Couldn't you then have direct sprites with a width of 32?
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Yes, they explain it on page 8:
"There is an added bonus to five byte headers. Because the end of DMA is indicated by the presence of a zero in the second byte of a header, and in a five byte header the width byte is not the 2nd but the 4th, a width of zero is valid in an extended header, and will be interpreted as a value of 32."


> Couldn't you then set the write mode for direct sprites, um, directly?
> Rather than having to use a dummy 5-byte indirect header?
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Sure, but you need to use a 5-byte header to set the write mode. So you'd draw that graphic with a 5-byte header, set for direct mode and the appropriate WM value. The WM value sticks, so you can use 4-byte headers in between, then another 5-byte header to change it back.

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