October 27, 1990
Joyce Porter
Problem Description: On the Tandy 3000 NL & HL the system does not properly recognize a change of diskettes.
Example:
After taking directory(dir) on drive A: <3.5"> you change disks and run (dir) on second disk and get the directory on the first disk.
This means that your system is not allowing drives to recognize disk change.
I myself realized this problem when after several months of installing various programs on my hard drive (some TSRs; Terminate Stay Resident) my diskette drives suddenly refused to change directory.
Upon calling various `experts' all over the country and receiving
bad information such as:
1.Your controller on your motherboard is out, you'll need to ship it off for repairs.
2.Your DOS is bad, you'll need to buy a new one.
3.Both your drives have gone out, you'll have to replace them.
Etc....
I finally reached someone on the Tandy support line who knew the answer.
All I needed was a couple of patches and drivparm statements for the IBMBIOS (hidden system file) and my config.sys file respectively.
I had to edit the drivparm statement for my situation; my A: drive is 3.5" 1.44meg and my B: drive is 5.25" 1.2 meg, however since the correct factors are listed in the DOS manual in the section on config.sys and drivparm statements it was easy.
The patches are as follows:
#A:>PATCH IBMBIO.COM,4E0C,74,EB#
The above patch is what actually enables DRIVPARM to be used.
#A:>PATCH IBMBIO.COM,1EA1,30,41#
This patch changes message seen at boot from "Tandy Version
03.30.00" to "Tandy Version 03.30.0A".
Once patches have been applied, edit the config.sys file (if you don't have one now is the time to create one) to include the following statement:
DRIVPARM = /DD:1 /F:2
##(Again the appropriate DD #'s and F # are listed in your DOS
manual according to diskette drive type)##
This drivparm statement defines drive B: as a 720k drive
To define drive A: as 720k drive change /DD:1 to /DD:0
##Their are specs for 5.25" 360k listed in DOS manual
NOTE:
To Print the doc file you may open in almost any Word Processor even DESKMATE TEXT and print from there or at the DOS prompt type "TYPE DRIVFIX.DOC" to read on screen or hit CTRL & PRTSCR together to send to printer.