Anybody? No? Disk. Anybody? No? Disk. Anybody? No? Disk.

10 out of 10 if you get that reference..

With the appearance of two rare machines in my garage i.e. the Cifer and (gasp) the Torch Triple X, I started to think about the media that came with them and what, if anything, I could do to preserve the software on them. 

Torch Triple X - Rare

Cifer 1887 - Also, a bit rare

Although I am a kid from the 70's I never owned a computer with a 5 1/4 inch floppy disk drive. I jumped from the ZX Spectrum+ to a SAM Coupe and then to an Amiga A500+. The Speccy used tapes and any floppy drives available for the speccy were way outside my 10 year old budget, costing more than the computer itself. Then the SAM used tapes or a 3.5 inch floppy drive and the Amiga also used the more modern 3.5 inch disks. So I had very little exposure to the delights of the greatest actual 'floppy' disk format.

Until now...

From having no 5 1/4 inch disks just over a year ago I now have boxes and boxes of them. A few are software for the Psion organisers, a big bunch are for the Cifer and the rest now for the Torch Triple X. All of these disks need to be preserved in some way, some more than others - for example the Torch has a 'key' disk that MUST be inserted the first time the machine is switched on or else it's just a large white box that does not very much. 

The first problem is that I don't have a PC with a 5 1/4 inch drive in it. I don't even have a working desktop PC that would accept one having long since succumbed to the portability of a laptop (even though my old HP is massive and weighs as much as a small child). The only physical drives I have are the twin drives in the Epson TF-15 unit, the drive in the Cifer and now the drive in the Torch. 

After some investigation I realised that I don't need a desktop PC to connect a drive to now that there is such a thing as a 'Greaseweazle'. This most excellent device with software by the ever awesome Keir Fraser is a small board that has a standard 34-pin connector and is powered by USB. More importantly it allows the contents of a disk to be captured regardless of its format (although common machine specific formats are supported natively too). This is achieved by the unit capturing a stream that comprises the variations in the magnetic flux on the disk surface itself. This can be saved into either RAW or SCP format for (in theory) writing to a new disk. Other formats can be written too.

It's worth noting that a floppy disk is basically a piece of plastic cut into a circle and coated in iron oxide that is somewhat the same as used in cassette tapes. Data is stored on the disk by magnetising small parts of the iron oxide in specific patterns. To read the disk back a read head simply converts the magnetic flux variations into electrical signals that are converted back into data. The Greaseweasle records this flux and puts it into a file for later use.

So the Greaseweazle I have is a V4 unit supplied by the excellent chaps at RetroPassion. The unit itself has a 34 pin connector, a four pin power connector and a USB type 'B' connector. There are also some jumpers that can be set, the most useful of which inhibits the units ability to write to a disk, providing some protection against idiots (who d'ya mean?) who might accidentally overwrite vitally important data...

It's not greasy and it's not a weasle...

I quickly 3D printed a case for it (find it here) and then set off to find a floppy drive. Because the unit uses a standard 34 pin connector this means that, in theory, any standard floppy drive will work including 3.5 inch drives, some 3 inch drives (may need an adaptor or the drives internal 5v disconnecting) and most 5 1/4 inch drives too. The first drive I found was a Chinon 'tall' 3.5 inch drive from an Amiga A500. 

After connecting it up I was disappointed to find that the drive did nothing, even with the power connected. After a quick search I found that some 3.5 drives use 12V which the GW cannot provide, requiring a separate power supply. The Chinon is one of them. Another quick scrabble in the garage produced a black PC unit that I had forgotten about. 

I wasn't sure what state this was in but I connected everything up and stuck in an Amiga disk - this is supposed to allow copying of disks agnostic of the system after all. :)

Mitsumi PC drive

Next question was what format to use. There are two main 'stream' formats. These are SCP and RAW. If using RAW you need to make sure you direct the output files to a folder and give them an appropriate name. The SCP format writes a single file so that's what I went for.

Initial results were disappointing. Using the HxC floppy emulator analysis tool the top layer was covered in orange and red and just didn't look right. After stripping the case off the drive I cleaned the heads and also realised that there was an adjustment slot on the spring holding the top head down. I moved it up to the highest setting and tried again.

Drive adjustment in progress...

Success! The stream created showed (almost) all green on the analysis tool in the excellent HxC floppy emulator software.

Then, using the HxC software, I converted the SCP stream into an Amiga ADF and successfully mounted it in WinUAE. Nice.

After this success it was time to move on to the 5 1/4 inch disks. As I had the Torch in pieces to try and repair the power supply I nabbed the floppy drive from that. Fortunately, the cable with this unit had the correct 34 pin connector for the Greaseweazle end. As I have a different laptop in the garage - a much smaller and slower HP that runs Linux I had to install the Greaseweazle software again as well as the HxC floppy emulator. Not quite as straightforward as the Windows installation but it all worked in the end.

First attempt at connecting everything up and the GW reported that it couldn't find an index. This normally means that it is looking for the wrong drive number. I changed the '--drive=' value in the command line to '1' from '0' and tried again but no luck. So I tried '2' and then jumped a mile as the drive clicked into life.

After reading in a disk image from a CPM system disk for the Cifer I was disappointed to see that the disk analyser showed large patches of red and orange as if the disk wasn't formatted or had errors. This was slightly disturbing but I persevered and tried to write the image to a blank disk and then analyse the pattern on the newly written disk. It did not go well.

CPM disk for the Cifer read using the Torch floppy
Something ain't right..

The scp stream written to a blank floppy and read back in
Definitely not right..

Hmmm. I started to think that this must be the drive at fault so, after some deliberation and a lot of moving stuff around I took the drive out of the Cifer and tried again. This time the results were startlingly better. Every track was green, dark green for data and light green for formatted but empty with only a couple of orange/red spots. Awesome!

That's more like it...

So, what is wrong with the Torch drive? I'll give you one guess. 

Yep.

Capacitors.

There are a few electrolytic caps on the control board of this drive and some of them have leaked. A video here from the most excellent Mike, showed that his drive of the same model was doing exactly the same as mine before being re-capped i.e. with a clicky bouncy arm thing. And, for the second time, replacing the caps fixed the issue (or to be honest, a partial re-cap as I didn't have all the values but it was enough.)

Torch floppy drive after (partial) recap

So, now can this drive read disk streams as well as the Cifer drive? 

It works!

Oh yes.

So, now I can capture disk images, regardless of format, can I write them to a blank disk and get them to work in the Cifer? Well, sort of. For some reason, just copying the scp stream back on to a disk always gives an error when the Cifer tries to boot.

Track 2, sector 9 every time... very odd.

Looking at the flux representation showed a strange fuzziness on the written disk compared to the original and I still don't know why. More bizarrely, this fuzziness appears if I use the Cifer drive to do the reading/writing too. 

Left box shows original, right box shows written disk with 'wiggle'

This could be down to my only being able to do a partial re-cap on the drive resulting in a reduced bouncy arm thing for reading (it's a 'head load' arm to be precise) but still slightly bouncy for writing. I will see about ordering the rest of the caps.

For now, I worked out that I could go via an intermediate format, in this case .IMD which is a format associated with a PC utility called 'Image Disk'. This is apparently a very useful and powerful tool but it requires a PC with 5 1/4 drives etc which I don't have. But the HxC software does write this format, as does the greaseweazle tools I think. In any case, after writing an IMD file of the CPM disk to a blank floppy I stuck it in the Cifer and booted it. 

And it worked! Yay!

Cifer booting! YES!

So, just one last thing. That 'Key' disk for the Torch. Can I read that too? You betcha!

Torch Key Disk Image - backed up and saved. Phew!

Back to the Torch next time.