cs161fhn@sdcc10.ucsd.edu (Dennis Lou) (01/30/91)
I just got a Teac FD 235 HF. It's a 3.5" 1.44 Meg floppy drive. Does anyone know what the jumpers on the back do? (besides the normal drive 0/1 select) If not, does anyone know Teac's phone number? I want to be able to bypass the media select switch so that 720k disks can be read/written in 1.44M format and vice versa just like a PS/2. -- Dennis Lou || "But Yossarian, what if everyone thought that way?" dlou@ucsd.edu || "Then I'd be crazy to think any other way!" [backbone]!ucsd!dlou |+==================================================== dlou@ucsd.BITNET |Steve Jobs and Steve Wozniak went to my high school.
c164-al@juliet.uucp (Joon Song) (02/01/91)
In article <16168@sdcc6.ucsd.edu> cs161fhn@sdcc10.ucsd.edu (Dennis Lou) writes: > >I just got a Teac FD 235 HF. It's a 3.5" 1.44 Meg floppy drive. > >Does anyone know what the jumpers on the back do? (besides the >normal drive 0/1 select) > >If not, does anyone know Teac's phone number? > >I want to be able to bypass the media select switch so that 720k >disks can be read/written in 1.44M format and vice versa just >like a PS/2. The TEAC drive has a row of jumper pins near the back of the drive. Of these, there should be 3 pairs labelled OP, HH, and LH. Normally, there is a jumper across OP, with no jumpers across HH or LH. In this mode, the drive with look for the HD hole to determine media type. If you remove the jumper from OP and put it on HH. The drive will assume that all disks are HD disks. If the jumper is placed instead on LH, the drive will assume that all disks are DD disks. There is a problem if you decide to move the jumper to HH. You will not be able to read or write 720K disks. The problem arises from the fact that most disk controllers use the media select switch to determine media type on 3.5" disks. So when the drive tells the controllers that it has a HD disk, the controller will try to read and write a 1.44M disk. There are two solutions to this problem. One is to find a controller which does not use the media select switch to determine media type. I have one such controller. It will read and write either formats (720K or 1.44M) from DD or HD disks. The other solution is to use a switch. I have found that if there is no jumper across OP, LH, or HH, the drive will read all disks as HD disks. So you can put in a switch across OP to set media type. When OP is shorted, it will look for the HD hole to determine media type. When OP is open, the drive will assume all disks to be HD disks. On one of my computers, I have rerouted the turbo switch to the disk drive to do this. Joon Song c164-al@bard.berkeley.edu