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Mail Archives: djgpp/1994/04/16/22:25:59

Date: Sat, 16 Apr 94 22:13:26 -0400
From: dj AT ctron DOT com (DJ Delorie)
To: gordon AT yrd DOT chem DOT washington DOT edu
Cc: djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: Re: Unsupported Interrupt -- Success, but still some questions

Note that the transfer buffer is available for use as temporary
real-memory space.  Its linear address is in the go32_info_struct (see
<go32.h>) and you can figure it's segment/offset from that.  It's
pre-allocated so you don't have to mess with allocating dos memory.

dosmemput/dosmemget are more efficient than farptr for largish blocks,
but farptr is faster for small fixed-size blocks (if you use 4-byte
transfers and the no-selector-argument version of the farptr calls,
presetting the selector in advance).  However, this overhead is much
less than the prot->real transfer call, which would be in the same
loop, so what's the point?

Note: if you're setting the palette registers, why did you need to copy
the data back after the call?

DJ


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