Opus Discovery Floppy Cable

Description

1 piece floppy cable for the Opus Discovery Floppy Disk system.
Brand new, made of top grade 3M ribbon cable.
Red wire to indicate line 1.
Approx. 25cm long (not too long, not too short for Opus Discovery, but tell us if you wish otherwise).

Straight cable (no twist)

This straight cable can be used to connect to:

• An original Opus Discovery drive: on an original Opus Discovery drive, you can select DS0 or DS1 by a jumper on the drive, so the cable can be ‘straight’ (no twist needed).
• A PC drive that is configured to drive 2 / drive B / DS1 (it’s the same), to have that drive function as the SECOND drive (drive 2 / DS1) on an Opus Discovery

Why not use a PC drive as first drive?

We could offer modified cables, that have wires 10-12 swapped, to make a PC drive act as the first drive on retro floppy disk systems, however..

On some Opus Discovery revisions, the first floppy connector (almost always soldered to the board), can only be used for the first drive, not for drive 2 (DS1), and the second (normally unused) floppy drive connector, can only be used for the second drive, not for drive 1 (DS0).
This is because some Opus Discovery revisions have separate Motor On signals for the drives, to avoid two original Opus Discovery drives to both spin up at the same time.
Using the second connector on the Opus Discovery for drive 1, or the first cable for drive 2, is not possible with these revisions.

Since it’s hard to determine which revision your Opus Discovery is, we decided only to supply the straight cable, that normally can only be used to use a PC drive as the second drive on Opus Discovery.

Now some PC drives to have the option to change them from drive B (drive 2) to drive A (drive 1): sometimes there is a soldering option on the bottom of the circuit board for this.
You need to check this for yourself though: there are many different brands and models of floppy drives.

PC Floppy drives, and differences in floppy cables

A modern PC floppy drive (3.5″ 1.44MB HD) is configured to drive B (DS1) on a PC by default.
This was introduced to make it easy to wire them up, without the need of configuring with e.g. jumpers.

To make this possible, PC floppy drive cables have a twist in them, to make that drive work as drive A.
PC floppy cables with connectors for two drives, have a twist between the two connectors that go into the drives: the connector at the end of the cable goes in drive A, and the one directly after it, goes in drive B.

PC floppy drives, 3.5″ HD 1.44MB, all work perfectly as DD (Double Density, 800KB) drives: the drives have been designed for this.
The head will perfectly read and write DD floppies, and once a DD floppy is inserted, the data transfer speed slows down to that of DD disks.

Now the standard IBM PC floppy cables can NOT be used for retro computer floppy disk interfaces, that have ‘Shugart’ pinout, which is different from the IBM PC pinout.
If you are using a 3.5″ HD 1.44MB PC floppy drive on a retro system like the Opus Discovery, you need to use a specifically made cable like the one we offer here.