View Full Version : Help Identifying Jumper Settings on a Kaypro 1 Floppy Disk Drive

May 10th, 2013, 09:15 AM
I'm struggling to figure out the jumper settings on a Panasonic JU-455-5 AAG drive I pulled out of a Kaypro 1. This is a 5.25" drive.

I've found little information about this particular drive online, but after a lot of research and trial-and-error testing, I've been able to figure out the following specs about this drive:
1. This is a Quad Density drive (it has 80 cylinders, so 160 tracks total using double sides).
2. It runs at 300 RPM with a data transfer rate of 250 kbps

It's basically the same as any 360 KB drive, except has twice as many cylinders (so it writes narrower tracks than a typical 360).

I'm basically trying to learn all I can about 5.25 drives in general, and a common problem I'm running into is just blindly trying different jumper settings without really knowing what any of the jumpers do.

This board has the following jumper layout. Was there any standardization between drive manufacturer's with regards to what these jumpers are named or what they do?


My best guess so far:

RD = Ready Signal Enabled
RY = PC XT-AT Compatible
WP = Write Protect
DS = Drive Selection Enabled
MM = Drive Motor Enabled
MX = Drive Selection by Drive Select signal
MS = Drive Motor Enabled by the Drive Select signal

May 11th, 2013, 04:34 AM
Here is a PDF on the internet that explains the jumper settings:


Google search string: Panasonic JU-455 jumpers

Good Luck.


May 11th, 2013, 01:50 PM
Thanks for tracking down that PDF, I have been looking at that one before I posted, but unfortunately it doesn't cover the AAG model. You're right though, it gives clues about what the jumper settings may mean - there does seem to be some consistency within manufacturer models.

This is my fourth half-height 5.25 floppy drive (one 360K, two 720K, and one 1.2M).

Just for kicks I plugged this Panasonic into my K10 today and it worked great! Maybe I'm wrong about it being a Quad Density drive?

Anyway, thanks for the help, just wondering if you guys knew of a central database/source for this kind of information. Seems like it's more hit-or-miss and internet searching, but that's part of the fun right?

May 11th, 2013, 04:30 PM
I thought the JU-455 was 48 tpi and the JU-465 was 96 tpi. Maybe my information is wrong.

May 11th, 2013, 07:04 PM
I thought the JU-455 was 48 tpi and the JU-465 was 96 tpi. Maybe my information is wrong.All my JU-455s are 40 track/48TPI, standard 360K drives often used in PC/XT; wonder where the OP read that it's 96TPI?