Re: A82: 6 by x sprite routines
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Re: A82: 6 by x sprite routines
I don't think it's all that useful since you still have to write a whole
byte to the port (obviously), so you're losing 2bits of potential
information. The other thing is that you'd have to write directly to the
data port, instead of using some bitplane in addressable ram (eg.
GRAPH_MEM), which tends to get awkward if you want to be able to easily
manipulate it later on, or if you don't plan on displaying the data
strictly in the order that you receive it; ie. direct cursor manipulation
is messy, especially things like "backspacing" it after a write when
you've got so few registers for quick temp. storage. The alternative, to
write a CR_GRBCopy-esque function for the 6bit mode is terribly wasteful
when you consider you'd need 1024 bytes as opposed to 768 bytes in the 8
bit case. Even if you "compacted" all those 6bit chunks into fewer 8bit
bytes, you'd still be faced with the problem of shifting them back into
position before the port write.
On the other hand of course, if for some reason, you needed to align 6bit
wide bitmaps so that they lie directly side-by-side (text, perhaps?), it
could be at least an "interesting" alternative to boring old shifting.
-Jeremy
... and to answer your question: I don't know.
On Mon, 2 Aug 1999, Kouri wrote:
>
> If anyone has read the newest version of 82-PORTS.TXT, Dines says something about changing the display controller mode so that you can use 16 columns of 6 pixel-wide "bytes" instead of 12 columns of 8 pixel-wide "bytes." I was just wondering if anyone has actually made a routine that utilizes this new information. Anyone?
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