PDA

View Full Version : Help with Tandon TM100



MeepsterNotchy
March 19th, 2017, 08:34 AM
Hello all, I have a Tandon TM100-4 floppy drive that I picked up yesterday. I plugged it in, and set the BIOS to 5.25 floppy. It was recognized in Windows 98 but would not finish initializing to format a disk (HD or DD). It would only be recognized if I set it as the A: drive, not the B: however, so I jumpered DS0. The thing is that if I understood the manual, I need a terminating resistor pack, which seems to be unavailable on the internet. My question is; what is the resistance of the resistors in the termination pack? (So I can get some at Fry's)

https://www.youtube.com/watch?v=bgP_4cOfGUY
Would these diskettes work?
http://i.imgur.com/t1IQsVi.jpg
http://i.imgur.com/NrO1IZd.jpg
Considering this drive can't read 1.2 MB disks, what 1.2 MB drive would anyone recommend?

Rick Ethridge
March 19th, 2017, 11:05 PM
The TM100-4 is a 100 TPI drive. It only stores 8 Mbits unformatted per disk. This, if I'm correct, is a 720k formatted drive that may require special disks.

modem7
March 19th, 2017, 11:45 PM
The TM100-4 is a 100 TPI drive. It only stores 8 Mbits unformatted per disk. This, if I'm correct, is a 720k formatted drive that may require special disks.
Per the document at [here (http://maben.homeip.net/static/S100/tandon/diskette/Tandon%20TM100%20Specifications.pdf)]:

TM100-1: 48TPI / Single sided / 40 tracks
TM100-2: 48TPI / Double sided / 80 tracks (40 per side) <---- 360K drive in PC family

TM100-3: 96TPI / Single sided / 80 tracks
TM100-4: 96TPI / Double sided / 160 tracks (80 per side)

TM100-3M: 100TPI / Single sided / 80 tracks
TM100-4M: 100TPI / Double sided / 160 tracks (80 per side)

modem7
March 20th, 2017, 12:42 AM
It was recognized in Windows 98 but would not finish initializing to format a disk (HD or DD).
Note the 'Deteriorated lubrication' section of the web page at [here (http://minuszerodegrees.net/5150_5160/tandon_tm100/tandon_tm100-2_problems.htm)].


The thing is that if I understood the manual, I need a terminating resistor pack, ...
In certain configurations. See [here (http://minuszerodegrees.net/diskette/5.25_floppy_drive_termination.jpg)].


My question is; what is the resistance of the resistors in the termination pack? (So I can get some at Fry's)
150 ohms, per the TM100 manuals. See [here (http://minuszerodegrees.net/5150_5160/tandon_tm100/tandon_tm100-2_terminator_2.jpg)].

SomeGuy
March 20th, 2017, 02:18 AM
The TM100-4 is a 96TPI Double Density drive. These kinds of drives are sometimes referred to as "Quad Density" drives.

IBM PC BIOS and DOS never officially supported these kinds of drives. The disk status signals are a tad different from a 3.5" 720k drive, the last time I tried connecting quad density drive to a PC, it would not recognize there was a disk in the drive if BIOS was set to 720k 3.5". You should be able to set the BIOS to 360k, and use a formatter that ignores DOS/BIOS to format 80 tracks for 720k.

You won't be able to easily read/write existing 360k floppy disks with this drive because PCs won't usually know it needs to double-step.

There was 5.25" media officially rated for 96TPI Double Density, but in practice any quality 48TPI Double Density 5.25" disk will work. High Density 5.25" disks will NOT work.

It is technically possible to read and write quad density disks (720k) using a 1.2mb floppy drive. For example, you can use ImageDisk to create images of quad density disks in a 1.2mb drive.

Chuck(G)
March 20th, 2017, 08:04 AM
It's easiest to lie to your computer and (assuming your computer BIOS allows this) to call this a 720K 3.5" drive--or use DRIVPARM or DRIVER.SYS in your configuration to override the BIOS selection.

Even calling it a 3.5" 1.44M drive might not hurt--just remember that you can't format a high-density disk that that drive--you'll have to explicit specify 720K parameters when you format.

MeepsterNotchy
March 20th, 2017, 02:37 PM
Would the diskettes in the updated OP work and what formatter would you recommend?

MeepsterNotchy
March 20th, 2017, 02:45 PM
Would the wattage of the resistors matter? Would 1/4 watt work?

MeepsterNotchy
April 3rd, 2017, 07:45 PM
Anyone?

Chuck(G)
April 3rd, 2017, 08:08 PM
Figure it this way: 150 ohms will see no more than 4.3V if pulled down by an open-collector driver.

So, power is going to be V**2/R or (4.3*4.3)/150 = 0.123W, so even a 1/8 W resistor will do fine.