Date : Fri, 01 Mar 1996 09:10:19 +0000 (GMT)
From : James Fidell <james@...>
Subject: Re: Emulation systems
> > I'm currently having a discussion with Wouter Scholten about the
pro's and
> > con's of the various methods. I agree that having one host file
correspond
> > to one BBC file is very convenient. I do however see compatibility
problems
> > with weird file names (as I think I've expressed earlier). The Beeb
allows
> > characters like "?", "*", "\" and "/" in their filenames, thus breaking
DOS
> > and Win32. I have seen commercial programs using "*" and "/". Also
> > DOS/Win32 have no distinction between upper and lower case - DFS does.
>
> How about using Linux's UMSDOS method? One file in each directory which
> stores 'extended' information. In this case, full BBC filename, load/exec
> addresses. (UMSDOS uses the file for storing the full UNIX filename,
> multiple timespamps and UNIX file permissions under a normal MSDOS FAT
> filesystem.)
>
> The file you *actually* store is something like 8 chars of the BBC
> filename (with wierdies substituted to '_' or something) with the
> extension set to a 'magic value'. The simplest case is a number which you
> use to lookup the correct entry in the index file. Eg.
>
> Files:
> BBCTAPE_.___ Index file
> BBC-FILE.000 file 'BBC-FILE'
> Q_FILE00.001 file 'Q.FILE0000'
> R_BBC_FI.002 file 'R.BBC/FILE'
>
> and the index file would contain entries like:
>
> Id# Filename Exec Addr Load Addr Next FileId#
> === ========== ========= ========= ===========
> 000 BBC-FILE FFFF8023 FFFF0E00 002
> 001 Q.FILE0000 FFFF4000 FFFF4000 001
> 002 R.BBC/FILE FFFFFFFF FFFFFFFF FFF
I like this idea -- I'll probably put something similar into Xbeeb v0.4
for the disk emulation.
James.
--
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- Lazarus Long | James Fidell