Date   : Tue, 18 Jul 2006 13:33:22 +0000
From   : Jules Richardson <julesrichardsonuk@...>
Subject: Re: Getting .SSD disk images onto a beeb...

BRAHMS wrote:
> 
> I've got a (not quite finished) program that will unpack a .ssd (or 
> .img) file.
> 
> The source code is available at 
> http://www.brahms.demon.co.uk/software/bbc/index.html

thanks - will take a look!

> (I use it to unpack the .ssd files and then transfer them accross and 
> set the start/exec by hand
> at the moment - I'm trying to come up with a better solution)

Well I suppose getting the data across isn't too hard, but I wouldn't have a 
clue how to write the necessary BASIC at the other end :-)

Presumably you could take the approach, at least for a first version, that the 
user's inserted a blank formatted disk at the BBC side of the right geometry - 
then you just use BASIC to receive file metadata (name, load addr etc.) plus 
the data for each file and store it on disk. OK, so it's not a faithful 
reproduction of the original disk at the sector level, but it serves for 99% 
of cases (exception being if any code on the disk makes assumptions about 
which disk blocks contain what, or which number file on the disk a particular 
file is etc.)

> The SSD/DSD spec just seem to be sector by sector dumps of the disc in 
> one big file (I used a watford dfs manual I downloaded from somewhere to 
> work out what was going on).

Fair enough - see other post; I just expected it to be a bit more efficient 
with empty sectors or sectors containing the same data - if it's just a raw 
dump it's easy enough.

I did write some code to pull files out of DFS disk images myself a while ago, 
but that was for ImageDisk format, not SSD. Eventually I came to the 
conclusion that I'd be better off porting it to Java before expanding it to 
handle other image formats and filesystem formats...

> - add a user friendly (i.e. non command line) interface

*shrug* Depends what it needs to do. If functionality is just "send a disk 
image" or "receive a disk image" then command line's fine and I'd expect your 
favourite graphical shell can be set up so that a right-click on a relevant 
file can invoke the command line util to do the sending bit. No sense bloating 
it with a fancy GUI!

cheers

Jules