Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!julius.cs.uiuc.edu!psuvax1!psuvm!ysub!msu!cmuvm!37kgllq From: 37KGLLQ@CMUVM.BITNET (Tony Papadimitriou) Newsgroups: comp.lang.pascal Subject: Re: bit problem Message-ID: <90323.23453237KGLLQ@CMUVM.BITNET> Date: 20 Nov 90 04:45:32 GMT References: Organization: Central Michigan University Lines: 17 am42+@andrew.cmu.edu (Alexander Paul Morris) writes: >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. There is fast bit insertion/exctraction sample code in the 386SX Programmer's reference manual (pp. 3-18 .. 3-22). It uses the 386-specific double-shift instructions. I am not aware of faster-than-usual way to do this on a 8086 or 286. ------------------------------------------------------------ Tony Papadimitriou, Computer Science Department, C.M.U. E-Mail: 37KGLLQ@CMUVM.BITNET