Magnum Opus

A lot has been going on in the last month. It’s been chaotic. The SoftROM continues to be a problem and is being investigated. So far, the toggle switches are suspected of bouncing, but even after smoothing that out, the device is still flaky. Investigation continues.

A while ago, I managed to pick up an Opus Discovery One disk drive. A large metal cased device that adds several features to your Spectrum 48K. The main one being a Double Sided Single Density disk drive. This was fine for way back when, but most modern users upgrade the unit. I’m no exception in this and as soon as I could, I ordered an upgrade kit from ByteDelight that included the extended RAM for use with HD disk drives, and a new QuickDos ROM v2.13. The upgrade kit is also available with one or two disk drives, but I already had one ready to go.

I also wanted to include a Gotek Floppy Disk emulator that I’d had for a while. This required flashing new firmware. I like the excellent FlashFloppy by Keir Fraser. The flashing of the firmware is pretty easy. Although I first tried using a USB to USB link, this didn’t appear to work very well in my case so I moved to the tried and tested Serial to USB technique and it worked first time.

FlashFloppy gives the ability to use many types of disk image and also enables you to customise the hardware with a very nice OLED display, Rotary Encoder for selection of files and even a piezo buzzer to make a noise like a real floppy drive!

Previous Gotek Customisation

As you can see in the image above from my previous Gotek Customisation, it creates a really cool device. FlashFloppy, at the time of writing this, is up to version 2.2. With the new drive, I wanted to do an extra neat job of installing the new hardware, so I took my time and created a 3D Printed bracket to hold the display at the right height. You can download it from my Thingiverse account to print yourself.

Gotek OLED Display Bracket Installed

The bracket, once fixed in (I used Hot Glue) allows you to simply slide the display into the correct position. A small dab of hot glue on the back of the display will secure it. I also used the option to flip the display and use the narrow text so that the aperture on the Gotek didn’t have to be modified at all.

Installation in the ‘Discovery case was a bit of a pain. Because the case had been designed with older SSSD drives, the mounting holes were incorrectly spaced and in the wrong position. I had to drill two new holes for each of the 1.44Mb Floppy Drive and Gotek. I also had to make up a straight 34-way to 34-way cable to connect in the Gotek to the second internal drive connector. I did this by taking a traditional floppy drive cable and adding an IDC connector before cutting the excess cable off. If you carry out this installation for yourself, pay attention to the orientation of the IDC connector and also the direction it plugs in on the PCB. I found that the original cable was fixed in backwards. This cannot be changed since the connector on the original cable is a transition type and is soldered down but doesn’t affect operation.

Cleaning the Mica Heatsink Washer

My ‘Discovery unit had obviously been opened before and the regulator removed and replaced. This meant that there was a lack of heatsink compound on both the bracket and the mica washer. Before rebuilding the case, I cleaned the bracket, the mica washer and the regulator tab with IPA (Isopropyl Alcohol) and applied fresh compound.

Finally, I remounted the plate carrying the drives and tested it. The worst thing is to close the case only to find that, for some reason, the unit isn’t working! Yes, I have done this before 🙂 After a successful test, carefully avoiding the mains on the exposed transformer! I replaced the case.

HD Floppy Disk Drive and Gotek Installed

I had found an archive of disk images to try out the drives with, so I formatted a floppy disk and copied over the files from the Gotek disk image for a test. I chose Outlet issue 14. It copied over faultlessly and ran from the floppy disk as it should. There are many more disk images to explore!

User Maryjan at has been working on recreating the Opus Discovery One PCB and has done a stellar job of it. I am lucky enough to have one of his early boards (Cheers Maryjan!) and intend to build it as time and finances allow. It is incredible that we have access to the tools to duplicate our old technology so that it can be enjoyed into the future.

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