Data Transfer from 8“ Floppies

[Klang Generator]

Hi all,

I am new to this list and du not really know much about the Intel development systems.

I reach out to you since I received a stack of 8“ floppy disks that as far as I know were created on an Intel Intellec system, maybe an MDS-800. But I do not know for sure.

The floppies contain information related to a musical instrument and I assume that the floppies contain source code as well as binary files burned to PROMs, I would like to figure out options to transfer the data from the floppies to a more current system.

I am living in Switzerland and therefore I am looking for any Swiss person who is familiar with the named Intel or compatible Siemens systems. Also if you know someone in Switzerland whom I might contact, please let me know how to contact this person.

Help is highly appreciated. 
Thank you very much in advance.

Kind regards,
Werner 

[Jon Hales]

Hi Werner

Welcome to Intel-devsys. You have come to the right place.

Firstly, it's very likely that you will be successful in extracting the files from your disks - most Intel disks were kept in good condition and the success rate has been close to 100%.

I can't connect you to anyone in Switzerland who knows the Intel development systems. But it's not necessary to have an Intel or Siemens Intellec system to read the disks you have. However, if you can get the floppy drive that was used to write the disks, that would be useful to give a fair chance that track alignment is good.

The recommended way to extract the data is as follows:

- with a well calibrated 8 inch drive (Shugart or other, 240v AC motor, 24v DC and 5v DC), read the data as flux transitions with a Kryoflux, Greaseweazle (or perhaps a FluxEngine or SuperCard Pro). The software for these flux readers is usually run under Windows but there may be versions for other operating systems. The designer of FluxEngine is in Switzerland and may be able to give you further advice. His software already supports a number of disk formats and he may be willing to customise it to suit your disks. Most of these devices require an adapter to connect a 34-way cable to the 50-way interface of an 8 inch drive (e.g. FDADAP from DBit in the US).

- with HxC Software Emulator, convert the flux data to RAW format - which is the default for the Kryoflux - one file for each track. ISIS disks are 77 track, single-sided, FM or M2FM (also written as MMFM) encoding,

- use Mark Ogden's flux2imd.exe (from a command line under Windows) to convert flux transitions to ImageDisk format (as sectors in HEX format)

- extract the files using Mark Ogden's unidsk.exe (from a command line under Windows). This parses the directory and combines sectors belonging to each file. Options allow the user to obtain detailed reports of the sectors that were read with errors such as mis-matching CRC. It may be possible to save files that had been deleted (if the sectors were not over-written).

The flux software will capture the sectors whether they are FM or M2FM encoded. If you know the encoding, you can tell the software to look only for transitions encoded in that format.

It should be possible to read each track in a single pass. Flux devices may be set to read each track 3 or more times. I recommend the Kryoflux because the software may be set to read a few tracks in each command line. This allows you to check that the drive read head remains clean and to remove any oxide that has been left on the head. The biggest risk with old disks is removal of good oxide by a build-up on the read head of oxide from the outer tracks on the disk. If your disks have been stored in good conditions, you may be lucky. I treat every disk as 'unknown' and so begin by reading  tracks 0 to 4. If the disk surface has mould or other contamination, deal with this before trying to read the disk. If the disk is hard to turn in the sleeve, cut open the sleeve and put the disk in a 'clean' sleeve.

[To elaborate on this point - all the flux readers were designed for 3.5 inch floppy disks. They assume that no damage will occur if 80 tracks are read without stopping and (except for KF) output a single file in a format such as SCP - the SuperCard Pro format is also used by the Greaseweazle. The assumption is not appropriate for much older disks].

If you know that the disks are all in FM encoding, it is possible to use Dunfield's ImageDisk (under a DOS OS) provided you have checked (with TestFDC) that the floppy controller system of your PC handles FM encoding.  [But this needs to read tracks 0 to 76 in a single operation and is not recommended if the disks are fragile]. This would get you to the position at which Mark Ogden's Unidsk.exe can extract the files. A search will get you to Mark Ogden's repository on Github.

If you find someone with a working Intellec, you may choose to use other methods such as exporting via the serial port (e.g. with Kermit under the ISIS operating system). But I would not advise the use of a floppy drive in a chassis that means the head cannot be cleaned easily. Always place the drive where you can see the head and keep a bright light to show if any oxide is on the head.

If you are willing to send the disks to UK, I would be willing to do the initial extraction of the data to flux transition files. This option would work best if you already have duplicate copies of every disk.

I hope that outline response provides some ideas about the alternative ways in which you can access the files on your disks. If you can provide photos of the disk labels, that might provide further clues that would allow me or someone else to offer more specific advice (e.g. if we can recognise file names characteristic of Intel's systems).

Best regards

Jon

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[Klang Generator]

Dear Jon,

wow. Thank you so much for your fast reply and the detailed information you added. I assume that the original floppy drive, where the disks were created, does not exist anymore. At least its current location is unknown. I am quite sure that the floppies themselves are in a rather good shape. So there will be a chance to read them.

I will provide some fotos of the labels when I return by end of next week as I actually do not have access to the floppies.

The alternative methods to read the data sound extremely promising. I have some 8“ drives but I will have to setup a system to continue as you propose. Also I have to get familiar with Kyroflux, Greaseweazle etc. to understand in more detail. But your information will help to proceed with this path.

So there already are two options which makes me confident that there is a chance to read out those old floppies even nowadays. Great.

And if all the threads are cut - I will come back to your offer and send some to you to the UK. 

I will come back soon.

Best wishes, Werner ツ