mort@ihuxn.UUCP (Dubman) (05/12/85)
It is true that when the disk drive gets "confused", it recalibrates the head and makes a banging noise. However, there is a special reason for it doing so when BLOADING a file that includes the section $400-$800 (hex) in memory. The problem is in BLOADING because there are many important DOS variables that are stored in that range. THe range from $400-$800 includes $400 bytes or 1024 bytes in decimal. In normal 40-column mode, there are 40 characters across and 24 down, which multiply to 960 bytes needed to store text. The other 64 bytes, scattered around not quite randomly in the text page. When you BSAVE you include in the file all the current DOS variables in that range, which do all sorts of things with the RWTS (read or write a track and sector) routine. The RWTS routine is the one that causes your disk drive to bang when you load a file into the text page. It loads the old variables over the new ones and totally confuses the disk drive. One solution, if it bothers you, is to load it somewhere else in memory and then do a memory move.