This doesn't have much to do with MASM, but I'm having problems formatting on this Tandy 1000 TX (80286) in DOS 3.3. I have as my "A" drive a 5.25" and as the "B" drive a 3.5" fdd. When I try to format with the B drive it will format the 3.5 ordinarily 720k disk as a 360k disk. I've tried the f:/720k switch and get "invalid parameter" every time, no matter how I reconfigure the syntax. I don't know enough about this version of DOS to be able to tell whether I'm asking it to do something it won't support. I'm getting my "f" switch information from a manual for DOS 5.0. I've tried to locate the various DOS capabilities by version on the net but haven't had any luck. I've read a little about including a config.sys file to do something to possibly address this problem, but am unsure how to go about that exactly. Thanks for any help.
Have a look at the "drivparm" command for config.sys - here is a link
http://www.csulb.edu/~murdock/drivparm.html
The format command for MS-DOS 3.3 does not support the /F switch, so AFAIK to format a 3.5-inch 720KB diskette, which has 9 sectors per track and 80 tracks per side, you must use:
FORMAT drive: /N:9 /T:80
For Michael's suggestion I got the message "parameters not supported". When I tried the DRIVPARM command I got something like "unknown config" or something like that, so I tried this: "DEVICE=/D:1/F:2" and got this message: "Bad or missing D:1". What I'm dealing with is a generic drive in a Tandy which fed its power thru the data cable. I had to modify the data cable by cutting 5,7,9, & 11 wires and grafting those to the red or five volt wire on a generic floppy plug. I then cut the 29,31, & 33 wires and grafted them to the yellow or twelve volt wire on the same plug. I ran the two black wires to the shield which should be at ground potential. However, I subsequently read in another info manual for Tandy floppies that one must cut the number two and number three wires also, so I may have a hardware problem. I'll try that. The 3.5 fdd will read 720k disks just fine, but when it comes to formatting, it isn't being recognized. Thank you all for your replies.
AFAIK Format depends on the BIOS for hardware information, low-level format, and read/write operations. What does the BIOS setup show for the diskette? What do the BIOS functions, other than those that write to the diskette, return for the drive?