Fairlight-CMI

I'm hacking together a utility to read samples off the Fairlight .IMD files that are kicking around, and generally poke about with QDOS disks.  I notice that on some sound disks there are files that have the first two bytes of the filename set to 0xff - does this mean they are marked as deleted?

Also, why are there occasionally large gaps in the catalogue between directory entries?  Deleted files that have been somehow "compacted" away?

-- 
Gordonjcp MM0YEQ

On Sat, Jan 04, 2014 at 01:03:23PM -0800, nossbocaj@gmail.com wrote:
> When I read the disks, I interpret the FF ones as deleted.  But I suspect that it also could be the old name if it was renamed. However that's just a suspicion.
>  
> 
>  Michael, most of the files are fixed sizes like CO and VC, so getting the size of those is not a problem. But some files, like sequences, can have different sizes. Where is that info? By the way, I've spent a lot of hours reading your source code, but since there's so many lines of code because of the great functionality, I haven't found that info.
>  

In MDOS it's the sector pointed to by the directory entry, apparently:

http://exorsim.sourceforge.net/mdos-tech.html

I suspect QDOS uses something similar.

Incidentally, this extracts .wav files from .IMDs without any tedious mucking about with Imagedisk (which is a source of anguish on non-DOS systems):

https://github.com/gordonjcp/cmidisk

--
Gordonjcp MM0YEQ

So far, the standard workflow for the extraction of samples from an imd-file is:

1) imdu.com file.imd file.bin /B

2) cmios9 -r -q1 file.bin

-> use "vc2wav *" to convert all VC files into WAV

In my opinion, it might be useful to write open source multiplatform tools “imd2bin” and “bin2imd” which could replace the old DOS programs. (Perhaps, somebody already wrote such tools, I have not searched for them yet.)

Regards,

Michael

On Sun, Jan 05, 2014 at 03:49:25AM -0800, kmi9000@yahoo.com wrote:
> So far, the standard workflow for the extraction of samples from an imd-file is:
>   
>  1)  imdu.com file.imd file.bin /B
>   
>  2)  cmios9 -r -q1 file.bin
>       ->  use  "vc2wav *"  to convert all VC files into WAV

I can't even get IMDU to even build.  It appears to assume it's being run on MS-DOS, on bare metal.

I got cmios9 working after a fashion, but not before I'd written my own .wav extractor.

>  In my opinion, it might be useful to write open source multiplatform tools “imd2bin” and “bin2imd” which could replace the old DOS programs. (Perhaps, somebody already wrote such tools, I have not searched for them yet.)

https://github.com/gordonjcp/cmidisk

If you look at the end of cmidisk.c you can uncomment a bit that will spit out the whole extracted image.  Note that although my crude IMD routine does unpack different disk sectors in the right order, it ignores head and track mapping blocks (just skips over them) and assumes that the cylinder and head are written in the correct order.  If you find any disks that do not provide the same output as IMDU.COM (check with md5sum) please file a bug on github.

-- 
Gordonjcp MM0YEQ

On Sun, Jan 05, 2014 at 12:02:37PM +0000, Gordon JC Pearce wrote:
> >  In my opinion, it might be useful to write open source multiplatform tools “imd2bin” and “bin2imd” which could replace the old DOS programs. (Perhaps, somebody already wrote such tools, I have not searched for them yet.)
> 
> https://github.com/gordonjcp/cmidisk
> 
> If you look at the end of cmidisk.c you can uncomment a bit that will spit out the whole extracted image.  Note that although my crude IMD routine does unpack different disk sectors in the right order, it ignores head and track mapping blocks (just skips over them) and assumes that the cylinder and head are written in the correct order.  If you find any disks that do not provide the same output as IMDU.COM (check with md5sum) please file a bug on github.

Okay, there's now a utility there called "unimd" which extracts a given IMD file into a bin file.

Be careful with it, and don't use it on the only copy of something you can't replace.  Do let me know how you get on.

-- 
Gordonjcp MM0YEQ