BBC Micro - assemblers - info needed

From: dave_at_cirt.net <(dave_at_cirt.net)>
Date: Wed Jan 22 12:38:24 2003

Quoting pete_at_dunnington.u-net.com:
> On Jan 18, 16:16, Philip Pemberton wrote:
>
> > Finally, does anyone know how some discs were formatted so they were
> > compatible with 40-track and 80-track disc drives?
> The way Acorn did that with things like the Master 128 Welcome Disc was to
> make all the directory entries (on track 0) point to tracks between 5 and
> 9, and 20 and 39. Track 20 on a 48-tpi drive is where track 40 would be on
> a 96-tpi drive:

One has to be very careful with the formatting - there where several different
FS formats - some with varying compatibility. (Talking about the file system
side here) The Master welcome disc used ADFS which was slightly more advanced
than the more common DFS that was used on the earlier Acorns.

I do have some scribbled documents which describe Acorn DFS in enough detail,
plus some sample code which will extract and create disc images which I can
send on (IIRC the code is actually on the web on one of the Acorn web sites - I
can't remember which one though!)

dave
Received on Wed Jan 22 2003 - 12:38:24 GMT