The most you can cram on a DD floppy

[mr_a500]

I was wondering if anybody has made any super-packed "emergency boot" floppies - a sort of "all-in-one" disk. I made one a while ago and I managed to get just over 1.5Mb onto one DD floppy - self extracting into RAM. I used lzx maximum compression (and while decompressing, files are listed in a nice font and with fancy copper rainbow background).

It's very strange inserting a floppy and having it automatically load everything into RAM - with no harddrive attached - and then removing the floppy and having a whole OS (WB3.1) complete with filemanager, text editor, binary editor, HD tools, SnoopDOS, jpeg and image viewers, sample player, archive extractor, and other misc. utilities on a completely silent Amiga (not even drive clicking). It even looks good (has Newicons, VisualPrefs, ModePro and copper rainbow).

So is it possible to cram more? Is there a better compression? Keep in mind that the extractor also has to fit on the disk (unlzx is only 21K).

I'd like there to be a contest to see who can make the most amazing DD boot disk. It's not just a useless endeavour - this packed bootdisk has saved my ass on many occasions.

[amigagr]

diskspare.device can store more data on the floppy than trackdisk.device but it's not bootable as far as i remember. it would be a good idea to use if it was bootable.

[InTheSand]

@Mr_A500: what spec of Amiga and how much free RAM is required to boot your emergency floppy environment? Just curious!

 - Ali

[Jose]

Well, I'm not much into compression algorithms but you just need to find a better one that doesn't occupy much space. I remember powerpacker did a hell of a great job back in the day, have you tried that ? But it probably occupies too much space (you could try to use just the library and create some small custom code using it. Also some functions of the library could be ditched out).
Just an idea, I actually don't know the size of the powerpacker library either maybe it's also too big...

[mr_a500]

@Mr_A500: what spec of Amiga and how much free RAM is required to boot your emergency floppy environment? Just curious!

My bootdisk was made for my A500 with 020, 2Mb Chip and 8Mb Fast. It would probably work fine on any Amiga with 3.0+ ROM and 2Mb+ RAM total. I'd love to share it for people to see how great my bootdisk is, if it wasn't for the annoying legality of it.

I already tried powerpacking all the large executables before adding them to the lzx archive, but surprisingly it made the lzx archive BIGGER. I guess the lzx compression works better on non-powerpacked files. I wouldn't even attempt to use a newer compressor like "RAR" because the unrar executable is a whopping 180K and uses huge stack and RAM to extract.

[Piru]

I already tried powerpacking all the large executables before adding them to the lzx archive, but surprisingly it made the lzx archive BIGGER. I guess the lzx compression works better on non-powerpacked files.

You're surprised? Uh, come on, this is obvious. You can't really compress data forever, and esp trying to compress already compressed data almost always results in larger file than the original compressed one.

And btw, PowerPacker isn't that good packer. LZX is way better.

[Piru]

The most obvious way is to have the first track as regular 11 sectors per track, then use diskspare.device method to store 12 sectors per track for rest of the tracks. Also use the extra 2 tracks having total 82.

This will give you 983KB per floppy, but is quite tricky to implement (mixed track format requires some special code).

[ChaosLord]

On my A1200 I format my floppies using FFS instead of the old A500 OFS.  This makes loading much faster and provides more space on the disk due to FFS does not "waste" as much space on every track/sector.

Donno if you can boot from it... but why not?  :-D

[mr_a500]

You're surprised? Uh, come on, this is obvious.

What surprised me was how much bigger it was (about 100K - 13% bigger). When you compress other compressed files like .jpeg or other archives (lzx inside lzx,lzx inside lha), they are the same size or only marginally bigger. I have seen some occasions when compressing a compressed file results in a smaller file (only up to 5% smaller).

Hey, good idea - I'll check out other filesystems and tracksizes to see if I can get extra space. It still has to be reliable though. There's no point in having a super-packed bootdisk that doesn't work when I need it.

So... nobody else has fancy bootdisks? (...or is it just that this is 2006 and everybody's using WinUAE?)

[rare_j]

mr_a500 wrote:
I'd love to share it for people to see how great my bootdisk is, if it wasn't for the annoying legality of it.

I was thinking about making a boot disk like this but don't know where to start. Perhaps you could share your disk without the bits that can't be distributed and we can fill in the gaps if you can tell us what's been left out. I would find it really useful I think.

[mr_a500]

Unfortunately, almost everything on the disk wouldn't be able to be distributed. The WB 3.1 parts can't and all the Aminet stuff - although free - cannot be distributed without the documentation and the documentation would take up way too much space on the disk. I suppose I could put the bootdisk image into an archive containing all the documentation, but I would still have to leave WB 3.1, Pageliner and DiskSalv off.

I could create a super-duper install that asks you to insert a WB3.1 disk, a disk containing Pageliner and DiskSalv and then it automatically creates a lzx archive matching my bootdisk - and then writes it to a blank disk that you insert.

No, on second thought, I don't feel like doing that. ;-) (maybe if I get extremely bored...)

[amigagr]

or, after you have finish the proces, post a file list here so everyone that have the proper files, can put them together and make a similar super-floppy :-)

[mr_a500]

I can do that. I can create a directory listing, include my prefs, fonts, startup-sequences and files that can be distributed. Then whoever wants to create it will have to add the missing files and lzx maximum compress it, then put on disk with the uncompressed startup files. (is anyone interested in this?)

[amigagr]

at least i do. i have already made an updated emergency disk with all the latest versions of the original disk files plus some extra stuff as a cli and diskmaster1.3 and mount files for pcmcia card flash reader for both pc and ffs formats but i think that all these are not enough!

-edit-
of course this setup still need the amigaos3.9 cd to boot...

[Brian]

Hmm... how about powerpacking everything, executables, datafiles the lot and then have powerpacker.library and powerpackerpatcher take care of all the hazzle?

PPP unpack PP files on the fly in the background when a tool access suck a file so the tool itself doesn't have to be PP friendly.

Dunno if it's practical but you might squeze out some more from a dd disk that way compared to using lzx and you don't have to unpack it all from the start? Dunno if there's not some XPK compressions that's better than lzx?