hgm@lanl-a.UUCP (05/18/84)
The diskette parameter table for DOS 1.0 through 2.0 is described on pages 137 through 141 of the 1983 edition of Peter Norton's book, "Inside the IBM PC" published by Robert J. Bradey Company. He describes a couple ways to change the table. However, in DOS 2.1, if you change the head settle time, and then access the floppy drives, the floppy driver (or some other code) sets the head settle time back again. It does not seem to set other parameters back if you have changed them. Is there anyone who knows the driver or the code responsible for doing this well enough to provide a patch to it?
borgia@cwruecmp.UUCP (The Prince) (05/26/84)
Changing the disk parameters appears to be very very sticky... I modified the table in RAM (taking tips from Norton and the net). Then I discovered that the table is reset the moment you exit the program that changed it (Debug or Basic). I figured it is reloaded from the disk every time. After some hacking, I discovered the hex string for the parameters on the boot sector (!!) and also in format.com (obviously). So I used utilities to patch the boot record. I even patched format.com and tried a newly formatted diskette. The result? The parameters get reset to the same old values. Apparently the disk parameters are controlled from ROM or somewhere I can't reach. I have not seen the parameter string in either BIOS or DOS. I would reaaly appreciate if someone who has really speeded up the disk will post the solution to this. Thanx --joe usenet: decvax!cwruecmp!borgia csnet: borgia@case arpanet: borgia.case@csnet-relay