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Twiggy disks dump & convert

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I have a full Lisa office suite in French on Twiggy disks.
My first objective would be to dump those disks in order to upload the images on archive.org and bitsavers.org. There is of course the problem that I don't have a twiggy drive, but I could lend the disks to someone that has one and would be willing to do the dump. 
Then there is the question of how to dump the content of the disks : I noticed that on Macintosh Garden or bitsaver there are images of twiggy disks in dc42 format. I can therefore assume that there's a way to do it, but how ? 
The second objective would be to convert those images to 3.5" format so that I could create floppies and install the software on my Lisa 2. Here again I'm turning to this forum to have advice on how this could be done. There would be also the question of deserialization. 
Any suggestion ?


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I have a Lisa 1 in the UK, and I dump Twiggy disks for free. The copy of the Pascal Workshop 1.0 on Bitsavers was recovered on my computer, as it turns out.


Generally Twiggy disks are dumped with the BLU utility running on the Lisa 1. The authors of BLU have adapted the .dc42 format to storing Twiggy data. This adaptation is "made up" in the sense that Apple never designed .dc42 to support Twiggy. Nevertheless, BLU's adapted format is the current standard and is used by other programs, too.


It is not likely that you will be able to run Office System 1.0 on your Lisa 2, at least not from floppy disk images. Twiggy disks hold 871k of data, which is more than will fit on any kind of 3.5" diskette supported by the Lisa 2, so you will not be able to create 3.5" diskettes that hold as much data as your Twiggy originals.


What we might try instead is using your disks (or, more realistically, copies of your disks, just to keep the originals safe) to install the Office System on a ProFile hard drive (or an emulator). We'd then take an image of that hard drive, install it on a hard drive connected to a Lisa 2, and see if it boots.


I've never tried this but I would not be surprised if it also fails to work, since the Office System 1 was created when the Lisa 2 did not exist. The software may be surprised to find the differences between the hardware of the two computers.


Some more notes on topics you have raised, and others:


1. I absolutely agree that your disk images should be uploaded to Bitsavers; however, I've not found its archivist to be easy to contact about sharing software. Your success may vary from my own. Archive.org is a different story, and it's of course likely you'll be able to share your disk images there. I'm very glad to hear that you're eager to do this.


2. I don't know that much is known about deserialising Lisa 1 disk images in particular, but I am confident that the Lisa community can figure it out. I don't think it will be difficult at all.


3. In your images I see the six Office System applications but not the binder containing the Office System OS software and manual. Do you have these disks in a different box, by any chance?


4. Although I am very enthusiastic about archiving Lisa software, given the current crisis I am not eager to augment the load on UK shipping infrastructure or to increase the number of people I have coming to my front door---and as such I'd prefer to wait several months before undertaking this archiving project. If you don't prefer to wait, you might see about joining the Apple Lisa facebook group, where another person in France has been showing images of a Lisa 1 running the French version of the Office System. Perhaps this person may be more able to assist you sooner.

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Thanks very much for this comprehensive answer and I'm reall thankful that you offer to gracefully dump the disks, Here are some comments about your message :



It is not likely that you will be able to run Office System 1.0 on your Lisa 2

John already confirmed to me that it would not be possible without some hardware modification. Anyway I don't have the Lisa OS 1.0 disks so my only hope was to install this french version of the Office suite 1.0 on my Lisa 2 which has Lisa OS 2.0 in english (on an x/profile CF card). Mabe it would be possible to do so if I send you the CF card (and also the x/profile card if you don't have it already). Given of course that Office suite version 1.0 in french would run on Lisa OS 2.0 in english on a Lisa 2.


On 3/28/2020 at 4:57 PM, stepleton said:

3. In your images I see the six Office System applications but not the binder containing the Office System OS software and manual.

No, I don't have the Lisa OS binder and software.


On 3/28/2020 at 4:57 PM, stepleton said:

I'd prefer to wait several months before undertaking this archiving project.

No problem at all, I'm not in a hurry and I understand your concern perfectly well. I can wait until the crisis is over.


On 3/28/2020 at 4:57 PM, stepleton said:

you might see about joining the Apple Lisa facebook group, where another person in France has been showing images of a Lisa 1 running the French version of the Office System

I will try to contact him to see if he has some experience about this french version of the software. I'm confident that, with the very active Lisa community we have, we can find a solution that benefits to all. There is also one person who may have bought the Lisa 1 those disks correspond to and if the dump of the disks are successful he may be interested in having a copy. We'll see.

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  • 8 months later...

I don't know the history of these floppy disks. I bought them a few years ago on ebay. The person I bought them from didn't tell me where they came from.


To dump these floppy disks, you need a Lisa 1 equipped with Twiggy drives. there is no other way.

I don't have a Twiggy floppy drive. My Lisa 1 no longer has them.

We have to see if Mr Stepleton is still okay with dumping our Twiggy disks.


For BLU, the documentation is here:

BLU manual

The part that interests us the most is in the section “Floppy Disk operations”.


My floppy disks are in my opinion at the end of their life and I'm afraid we will only get one read.


Let's wait for what Stepleton offers us.


Just a question Pascalg: are you french? (I’m french, from Marseille).

Edited by kingofloose
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38 minutes ago, kingofloose said:


Just a question Pascalg: are you french? (I’m french, from Marseille).

Not quite French, but I’m Swiss, from the french speaking part (in Lausanne). I always try to find french versions of software and the Lisa os1 is a very rare one.

@stepletonhas been very kind to help dump the french Lisa Office I have and spent an extensive time trying to recover data from them. Unfortunately they had lots of mold residues on the surface and even with cleaning with special products he was not able to extract data. Let’s hope that your floppies are in better shape. 

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I can confirm that it is possible to run LOS 1.x on Lisa 2/5's. When I bought my X/ProFile from vintage micros, CF cards containing LOS 1.2 or 1.1 were included and these boot without issue. But ofc, 870KB disks won't be accessible as the hardware just isn't there.


That said you'd absolutely need a working Twiggy drive to image these using BLU. Once that data is recovered in dc42 format, whatever steps are next could be taken. But the first and most important step is to read the media successfully.


Even if your existing media might be bad, using BLU you could create copies onto modified 5.25" HD disks (so they can fit in a twiggy drive and have the extra data window) and then attempt to install them to a ProFile and them image that profile.


I don't know about LOS 1.x. but I do have a tool deserialization program in LisaEm 1.2.7 that can be used.


Basically there's a "Protect" flag that's enabled on the equivalent of the inode like extent blocks block that can be disabled. I can't say whether or not this is in the same location for LOS 1.x vs LOS 2.x/3.x, but that can be found out with experimentation via LPW. i.e. you can copy an unprotected tool/application to/from twiggy media and image it and look at the inode like extent blocks. These extent blocks have the same file id as the block number they live on minus the OS boot blocks, but they are 2's complemented. So it's easy to find them as tag bytes 4,5 as a 16 bit word are negative.


So if the file ID is 15, you'd see tags 4,5 in two's complement form of the number 15, and these would live 15 blocks after the MDDF (superblock), and so you'd see FF F1 at tag positions 4,5.

This code is used to null out the bozo bit (aka protect): https://github.com/rayarachelian/lisaem/blob/09afe9e998752d4458d8c9d1fdab2c562a4c628e/src/tools/src/los-deserialize.c#L55


So likely LOS 1.x has a very similar flag somewhere in that block for serialization, possibly at a slightly different position. But again, you can do something like copy the clock or the preferences app to FileWare, dump that out and then try it with a protected tool such as LisaWrite or LisaCalc and see if you see extra bits turned on in the extent block.


I can probably spend a couple of hours with the existing twiggy disk images off bitsavers and the X/ProFile disk images of LOS 1.x myself and figure this out.


But there's a couple of more important things to worry about:


  1. is how is the virus affecting affecting postal service between Switzerland and The UK.

  2. Is Brexit going to be an issue in terms of how fast packages can get through.

  3. How do you safely protect the twiggies from being erased by magnetic fields as it passes through the postal systems/customs? - I'd suggest wrapping them in two boxes with lots of space between the outside box and inner box, and then wrapping the inner box with aluminum foil to create a faraday cage. But not sure if this will cause customs to mess with the package and when they open the package somehow damage the media itself. The two box method will provide distance from the outside to the inside thus lowering the magnitude of any magnetic fields from motors. Wrapping the inner box with foil will help deflect the rest.

You'd want the inner box immobilized inside the outer box, this would mean using very tight bubble wrap rather than air filled bags.

I'd also mark the outside with "Magnetic media enclosed." but that might not mean much to postal employees anymore.


If you're going to send Tom your twiggy media, and he's willing to image it, (I'm making two large assumptions here) I'd do it sooner rather than later before it gets even more difficult. Again, we can worry about how things are installed on ProFiles or deserialized later. It's far more critical to get the media imaged first.


Once it's imaged, you practically have all the time in the world to mess with it and analyze it.

Edited by sunder
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Hello! Yes, I am quite willing to give it a shot, although the process is not necessarily fast! And as the experience with Pascal demonstrates, results are not guaranteed. I tried my best to recover LisaList and was not successful over multiple rounds of cleaning and attempting to image, and so gave up there. There was too much mould to clean without removing the media from the disk envelope, and even then success would not have been assured.


Ray's warning are also pertinent here --- I'm fairly confident in the ability of Royal Mail and other parcel shippers to deal with the virus and lockdowns, but Brexit is another matter and could cause a whole lot of chaos. For that reason, it may make sense to wait until either there's more clarity on what could happen next. If there will be no deal, then it may make the most sense to delay until early next year --- or find someone in a different country to do the imaging in the meantime. It's worth noting that there may be options besides finding someone with a Lisa 1: a flux recorder that uses a more conventional 5.25" floppy drive might also work.


Regarding cleaning: per the advice of folks like Al Kossow, my solvent of choice for cleaning the media is cyclomethicone, and while it's found in cosmetics, it's something I prefer to use outdoors if I can. (I might be being too cautious!) In Britain, the outdoors is generally not a great place for floppy disks this time of year, so we might need to think of a different way to do the work --- maybe I can improvise some kind of enclosure. Hopefully your disks are in good shape, though, and don't require any cleaning.


Pascal shipped his disks in a double-box arrangement, with at least a few cm of clearance around all sides of the inner box (an ordinary 5.25" disk container like the ones that disks were sold in). There was no foil, but I'm not sure that this would help so much with magnetic fields that might damage the media contents. Marking the box as Ray suggests seems like a good idea to me.


A quick question: do your disks have an odour to them? Do they smell like wax crayons? If so, this is a pretty sure sign of mould, I think.

Edited by stepleton
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Here is the current state of the floppy disks. (See pictures).

Number 1 (the one with the white rim) appears to be in very good condition, no mold or deep grooves.

The second, (which doesn't have the white rim) worries me a little more. There are slight traces of mold but no deep grooves. However, the quality of the second floppy appears to be significantly worse than the first. In any case, it will be necessary to count on only one reading.

Is it possible with BLU to copy a specific sector of the floppy disk in order to clean the heads of the Twiggy drive and thus avoid in the event of the ferromagnetic layer being torn off the following tracks which could have been read as normal?


As for my personal experience with postal exchanges between England and France, currently the Royal Mail has lost a package and I will probably never receive it.

So I prefer to delay if I have to send the floppy disks.

I have another lead with John Woodall who knows someone with a Lisa 1 who could make a copy.

Regarding kryoflux with a conventional 5.25 drive, don't we run the risk of running into the problem of variable rotational speed on Twiggy drives that we don't have on conventional drives?




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The disks look somewhat better than Pascal's did :lisa:


While there is localised discolouration, I'm not seeing the white crust that you find on really mouldy disks. It's possible then that what we're observing is media degradation of a different kind (oxidation, delamination, etc.), which may not be too uncommon either. I wouldn't assume in any case that the disks will be unreadable.


My experience with BLU is that sometimes it recovers itself and reads beyond tracks with bad sectors, and sometimes it doesn't. My hypothesis is that failures to recover aren't really BLU's fault. The floppy drive subsystem is controlled on the Lisa by a 6504 processor on the I/O board (in other words, a general purpose machine, not an ASIC), and the program it's running may not be robust to certain kinds of errors. So, on Pascal's disks, there were occasions where the drives would become unresponsive (sometimes the one reading his disk would be stuck spinning), and only the reset button would recover the machine to a usable state. The documentation for the floppy subsystem in the Lisa Hardware Manual suggests that it's as overengineered as the rest of the computer, so I think that it's not unreasonable to be suspicious if it.


If my hypothesis is correct, it suggests that a "BLU Pro" would be handy, something that allows you to manually specify the order in which you'd like to read sectors and tracks --- that way you can work around the places on a disk that seem to cause the I/O processor so much trouble. I've contemplated writing such a program, but it's far down on my list of things to do. Maybe someday.


There are other delivery services besides the Royal Mail: UPS, DHL, etc., all of the usual ones work. But it's important to pick an option you're comfortable with, and Brexit in any case means it's a good time to wait before shipping anything here.


I've never used a KryoFlux, so I don't actually know if it would do the job --- I suppose I'd assumed that since it was capturing analogue recordings of the disk, you could work out the details in software later even if certain tracks were recorded at non-typical speeds, as long as the entire recording mechanism has enough bandwidth. I had emailed the person behind FluxEngine, however, and I think he'd told me that the problem for the Twiggy format for him was the track spacing, so maybe there are some details that make flux recordings not workable with current systems. In any case, it would be nice to have another mechanism besides a genuine Lisa that could do the job.

Edited by stepleton
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On 12/12/2020 at 1:57 PM, stepleton said:

I've never used a KryoFlux, so I don't actually know if it would do the job...


The KryoFlux would not be much help here.  The Twiggy is 62.5 TPI drive, and I don't know of a "standard" drive that will interface with the KyroFlux that is also 62.5 TPI.  Standard 48 TPI or 96 TPI drives will not be able to position the head correctly to read the Twiggy formatting. 


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