Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!gem.mps.ohio-state.edu!sunybcs!bingvaxu!bingsung.cc.binghamton.edu!consp21 From: consp21@bingsung.cc.binghamton.edu (Ken Hoover) Newsgroups: comp.sys.ibm.pc Subject: Re: Charity Keywords: wretched, pity, good counsel, ignoramus Message-ID: <2570@bingvaxu.cc.binghamton.edu> Date: 24 Oct 89 01:20:39 GMT References: <13091@boulder.Colorado.EDU> Sender: usenet@bingvaxu.cc.binghamton.edu Reply-To: consp21@bingsung.cc.binghamton.edu (Ken Hoover) Distribution: usa Organization: SUNY Binghamton P0D Consultants Anarchy League Lines: 84 In article <13091@boulder.Colorado.EDU>, johnsobm@boulder.Colorado.EDU has a lot of questions, and I'll answer the ones I can... > 2. What is interleaving? > Interleaving, with respect to hard disks, is the technique of alternat- ing sector numbers around the track on the disk itself to obtain the fastest data-transfer rate. Interleave is expressed in a ratio (1:1, 2:1, 3:1, etc) to express how far apart the sectors are on the disk in terms of how many sectors are between sector n and sector n+1. For example, the physical placement of the sectors on a drive with 1:1 interleave is: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 (at 17 sectors/track) but is 0 9 1 10 2 11 3 12 4 13 5 14 6 15 7 16 8 on a drive with 2:1 interleave. (have I got that right?) The idea is the same as the interleaves get higher. The controlling factor that a slower controller will not have enough time to get the data from a sector into the memory of your computer before the next sector to be read has rotated out from under the head of the drive, and will have to wait until the sector that needs to be read next comes around again. Interleaving that is too "tight" will mean that it takes one (or more!) rotations of the platter to read in multiple sectors. A correctly set interleave will allow a disk to read an entire track in as few revolutions of the platter as possible. i.e. being able to read an entire track in just three rotations of the platter if the interleave is 3:1. A controller with 1:1 interleave will be able to read a track into the memory of your machine as fast as the drive can spin the disk under the read/write head. (Most drives run at about 3600rpm) There are several packages (most notably SpinRite) that will analyze your disk and correct the interleaving to create the highest throughput through your controller. [...] > > 2. In a similar vein, what do the fans of the various C implementations > say is the major advantage/raison d'etre/necessity of using C over, say, > Turbo Pascal, or TP & assembler? > Well, the reason I most often hear for using C over Pascal (in any implementation) is that C produces "tighter" code (i.e. you can do more with less typing). However, this advantage is offset by a (considerable) decrease in readability. Personally, I think that "C" stands for "Cryptic"; but that's my opinion. C is now the language of choice for system programmers, and is (unfortunately) a must of you wish to understand the UN*X operating system to any degree at any level below the prompt. As you have probably guessed, I am not a fan of C as a programming language - but I know of literally dozens of people who swear by it. Whether you like it or not boils down to personal preference, I guess. > Thanks for any input (or is that gauche?) > > johnsobm@spot.colorado.EDU > (I am an even parity voter) I hope I helped. (Bracing myself for another wave...) ------------------------------------------------------------------------------ Ken Hoover [ consp21@bingsuns.pod.binghamton.edu | consp21@bingvaxa.BITNET ] Resident computer jock and Mac hacker, SUNY-Binghamton Bio dept. Senior undergraduate consultant, SUNY-Binghamton Computer Center ------------------------------------------------------------------------------ Disclaimer : just becasuse I program Macs doesn't mean I can't program my XT either... :-)