connery@bnrmtv.UUCP (Glenn Connery) (01/23/86)
A better patch for avoiding the floppy diskette timeout problems on ATs running xtals >15MHz... ; ; Change Diskette Parameter Table's motor startup delay ; by Glenn Connery, BNR, January 1986. ; ; The Diskette Parameter Table is pointed to by interrupt vector 1E at ; address 78H. The table consists of 11 bytes (0..A) the last of which ; is the motor start up time, in 1/8ths of a second (normal clock). By ; modifying this value you can correct for the faster crystal installed ; in your PC-AT. ; ; The normal value is 8 (is 1 second). Running a 9MHz machine instead of ; a 6MHz machine means that 0C (or 1.5 seconds normal time) should be used. ; ; No warranty is made of the suitability of this program for any purpose ; nor any guarantee that it will function as specified. Use it at your ; own risk. ; code segment public assume cs:code,ds:nothing org 100h ; : start: mov ax,0 mov ds,ax ; mov bx,ds:[78h] ;offset mov es,ds:[7Ah] ;segment ; ; and finally, stuff the new delay period into the appropriate place in the ; table... this is the byte to change for different crystal speeds ; mov byte ptr es:[bx+0Ah],0CH ; exit: mov al,0 mov ah,4ch int 21h ; code ends end start ----- Glenn