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View Full Version : 5 1/4th floppy drive jumper settings



Culbrelai
June 17th, 2017, 04:59 PM
Hello, just discovered this forum looks like it'll be useful for my newfound hobby, already have been a modern computer guy for some time, hehe.

In any case, I recently acquired a Mitsubishi MF504C 1.2 MB 5 1/4th floppy drive off ebay (tested and working so I jumped at it, every other one seemed to be sold as is)

Got it to put in my Windows 98 machine, a Micron Millenia MXE, mobo is a H55Hi-Plus.

To make a long story short the drive works but incorrectly shows up in Windows 98. When I set it (rightfully) as a 5 and 1/4th 1.2mb drive in the BIOS it has an error. Oddly enough I put it into 1.44mb 3.5 mode and it works great, even shows the floppies having 1.15 MB in them. Successfully reads and writes to the floppies as well. So clearly something is wrong with the jumpers as I've tried everything else. The floppy cable is brand new and is verified to be working (tested with my 3.5 floppy drive) and its the type with a twist.

My question is what are the correct jumper settings for the standard setup where A: is the 3.5 floppy and B: is the 5.25, and where to put each of them on the cable, before or after the twist? I've found a small manual for my exact drive http://www.minuszerodegrees.net/manuals/Mitsubishi/Mitsubishi%20-%20MF501C%20and%20MF504C%20Flexible%20Disk%20Drive s%20-%20Installation%20Guide.pdf but it's quite over my head, I'm used to SATA where it's like "Plug in whatever the hell you want and it'll work!" Hopefully it will help you help me? Thanks in advance.

modem7
June 22nd, 2017, 01:34 AM
Welcome to these forums.


I've found a small manual for my exact drive http://www.minuszerodegrees.net/manu...on%20Guide.pdf but it's quite over my head ...
The jumper settings of the drive for your Window 98 machine will be how they would set for an IBM AT. So per the 'MF504C' column in the 'Customer jumper options' table, use the defaults (what is indicated by the small circle).

Per the diagram at [here (http://minuszerodegrees.net/images3/floppy_crossover_cable_wiring.jpg)], the drive-select setting is the second one (DS1 for the MF504C) irrespective of where the MF504C is on the twisted cable (before or after the twist).

Termination ("terminating resistor pack") is per the diagram at [here (http://minuszerodegrees.net/diskette/5.25_floppy_drive_termination.jpg)], although contradicting that, is the last sentence in section 1.(2) of the guide you pointed to. It may not matter.


To make a long story short the drive works but incorrectly shows up in Windows 98 ...
Windows 98 is probably using the BIOS setting as its information source.


... When I set it (rightfully) as a 5 and 1/4th 1.2mb drive in the BIOS it has an error.
Specifics help. What is "it" ? The BIOS gives an error, Windows 98 gives an error, or the drive makes a horrible sound ?

Anyway, maybe you are about to tell us that you found that one of the MF504C's jumpers was set incorrectly.