5 1/4 floppy drive jumper settings (Mitsubishi MF504C-318UG) \ VOGONS

5 1/4 floppy drive jumper settings (Mitsubishi MF504C-318UG)

Topic actions

First post, by thevdm

Posted on 2021-09-25, 16:29

thevdm Offline

Rank Newbie

Rank: Newbie
Posts: 41
Joined: 2018-03-12, 18:48
Location: Kent, UK

Hi,

I have a 5 1/5 floppy drive that I would like to use in a 486 build that I'm working on.

The drive I have is a Mitusbish MF504C, 1.2M. When the computer posts and checks the floppy drives the head moves as expected and no errors are displayed. Once Dos has loaded, selecting drive B results in the flopy disk spinning but no movement from the head. After a moment Dos returns "Drive not ready".

The 5 1/4 drive is on the first position of the FDD cable (before the twist) and there is a 3.5 floppy drive in the second position (after the twist) - Because of this, I have removed the terminating resister pack and removed the link on the "TD" jumper.

Having tried many combinations and feeling a little out of my depth, can anyone confirm if the jumper settings are correct? I have owned this floppy drive for a few years now and have never seen it work.

The attachment floppy jumpers.jpg is no longer available

In the image above, I have highlighted the currently connected jumpers with a red box around the label.

Thank you in advance
Jim

Gaming rig: Dell Dimension XPS T500 - PIII 500 - 288MB RAM - Voodoo3 3000 - SoundBlaster Live! Value - DVD-ROM - CD-RW - 3.5" 1.44 - 98SE & 2000 dual boot
A nostalgic pile of laptops from the late 80's to late 90s.

Reply 1 of 6, by Horun

Posted on 2021-09-25, 17:15

Horun Offline

Rank l33t++

Rank: l33t++
Posts: 6334
Joined: 2019-09-19, 02:19
Location: USA

This has the "initial" jumpered positions: http://minuszerodegrees.net/manuals/Mitsubish … ion%20Guide.pdf
DC for Disk Change needs be jumped, move from SR to DC. Here is an enlarged picture of default jumpers for MF504C

Hate posting a reply and then have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. Stuff: https://archive.org/details/@horun

Reply 2 of 6, by thevdm

Posted on 2021-09-25, 17:34

thevdm Offline

Rank Newbie

Rank: Newbie
Posts: 41
Joined: 2018-03-12, 18:48
Location: Kent, UK

Hi Horun,

Thank you for your answer, I have moved the SR jumper to DC, unfortunately this made no difference to the behaviour of the drive.

Many thanks
Jim

Reply 3 of 6, by Horun

Posted on 2021-09-25, 19:00

Horun Offline

Rank l33t++

Rank: l33t++
Posts: 6334
Joined: 2019-09-19, 02:19
Location: USA

Hmm So it passes a BIOS Seek test but does not come ready with a formatted disk in it ? maybe it does not like the controller or the drive has a sensor failure or other bad part.

Hate posting a reply and then have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. Stuff: https://archive.org/details/@horun

Reply 4 of 6, by snufkin

Posted on 2021-09-25, 20:24

snufkin Offline

Rank Oldbie

Rank: Oldbie
Posts: 1197
Joined: 2021-03-18, 18:58

Does the indicator light turn on at all? And does it still turn on if you jumper IR?

I think IR sets it so that the LED only turns on if the drive is Ready, so if it stops coming on after you set IR then it might mean that the drive never becomes Ready. Index and Read data are both only sent when the drive is in the Ready state.

There's what looks like a fairly complete set of instructions for the 504B here: http://www.minuszerodegrees.net/manuals/Mitsu … ion%20Notes.pdf

Reply 5 of 6, by wondow

Posted on 2021-11-10, 02:17

wondow Offline

Rank Newbie

Rank: Newbie
Posts: 4
Joined: 2021-10-11, 18:30

Mine didn't work at first, but I managed to make it to work. Here is my configuration:

file.php?mode=view&id=123363

Reply 6 of 6, by perhenden

Posted on 2023-06-20, 19:51

perhenden Offline

Rank Member

Rank: Member
Posts: 133
Joined: 2020-04-11, 13:34
Location: Oslo, Norway

wondow wrote on 2021-11-10, 02:17:

Here is my configuration:

Many thanks! That got my two drives working!

For reference, in case it can help someone later, the jumpers on my MF504C-318M was originally set like below.

Drive marked with drive letter A (MF504C-318M -rev A):
HR, MM, MS, IR, DC - DS1 - SB

Drive marked with drive letter B (MF504C-318M -rev B):
IL, MS, IR, IU, SR - DS0, TD - SB

Go to top of page Go to top of page

Back to General Old Hardware