Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!julius.cs.uiuc.edu!psuvax1!rutgers!rochester!pt.cs.cmu.edu!o.gp.cs.cmu.edu!andrew.cmu.edu!am42+ From: am42+@andrew.cmu.edu (Alexander Paul Morris) Newsgroups: comp.lang.pascal Subject: bit problem Message-ID: Date: 19 Nov 90 16:52:26 GMT Organization: Carnegie Mellon, Pittsburgh, PA Lines: 12 It's really fast to move memory around, but what if you have to access certain individual bits. Is there any fast way to read/write a bit to memory? The application of this is for stuff like saving/retrieving graphics windows from disk. It goes very fast for the part of the window that fits on a byte boundary, but anything over the bounday (not a multiple of 8) has a for-do kind of setup that reads a bit, etc, etc. But that slows it down A LOT. It takes longer to manipulate several rows of bits in a window (not on a boundary) than it takes to save the whole screen (using a blockwrite or mem move). Alexander Morris "People die, things change... Carnegie Mellon It's sad."