Date   : Wed, 05 Feb 1997 19:47:25 +0000
From   : Mike Tomlinson <mike@...>
Subject: Re: Disk image formats?

In message <32F5A40F.479@...>, Robert Schmidt <rsc@vingmed.no>
writes
>
>I consider that a theoretical problem only.  Most people will have the 
>common sense to store the games in a compressed, archived format (like 
>ZIP), unzipping only the games they are interested in at the moment.  
>Besides, with the sizes of today's disks (it's now hard to get a new PC 
>with a smaller disk that 1.5Gb), the waste is hardly noticeable.

True. :-)

>It's not hard, just relatively time-consuming.  With a good ASCII-text 
>extractor (a la "strings" on UNIX), a BBC BASIC to text translator,  
>"grep" and a bit of common sense, it's quite easy to put the correct 
>files together...

True again.

>I'm going through lots of Watford DFS disks these days, extracting 
>individual games.  I will however, keep offering the original disk 
>images on my web/ftp site, for those who enjoy disk menus and 
>compilations.

Ahhh.... many of my disks are Watford DFS 62-file format.  Having had a
chance to play around with Tom Seddon's 62-file to archive converter
(confusingly called dconv, the same as his image format-to-DFFS
converter), and read documents on the archive format from Robert's and
Wouter's sites, I have come round to the idea of using the archive
format.

Seeing as the archive format is being proposed as the standard method of
BBC file distribution, I am keen to support it.

>I think the BBC community will be very grateful to you no matter how you 
>make the software available - as you say, conversion from disk images is 
>no problem at all.  DFFS is currently the only "one-way" format, until 
>someone produces another conversion utility (Tom? :) ...

I didn't intend to provide DFFS format images as this would mean they
were only usable on one emulator.  My initial intention was to provide
raw disk images.


That said, I have had some success reading BBC disks on the PC.  I was
able to read 40 track BBC disks on a PC 360K drive no problem, but was
completely unable to get 80 track discs to read on a 1.2M drive.  I'm
using Wouter's modified version of FDC.

I got round the problem by connecting my old BBC 40/80 switchable drive
to the PC and can now read any BBC disc (except protected ones).

Finally, I have some discs of games produced using Vine Micro's TD ROM.
This was a utility rom which allowed one to copy games from tape to
disc,  but the images written to disk were serialised and could only be
loaded by the TD ROM that produced them.

The TD ROM won't work on Tom's emulator, presumably because it doesn't
support OSFIND.  If Tom does get round to supporting OSFIND I will ask
Vine Micros if they have any objection to my publishing the TD ROM image
along with the games I copied using it.

Finally, I am struggling with a horrible HTML creator (Hot Metal Lite)
and as soon as I have a halfway decent homepage up I will start
uploading BBC files.  Once it's ready I'll post here with the address.

regards,


-- 
Mike Tomlinson
Alexander Graham Bell's worst nightmare: "This is Watson, I'm
sorry I can't come right now, please leave a message."