6 Dec
2002
6 Dec
'02
6:56 a.m.
All these terms are waking up old memories (and brain cells) from my
youth...I used to do some low level programming as a kid on TRSDOS 1.3
in my parent's basement. Thanks for the pleasant memories.
-Chandra
-----Original Message-----
From: cctalk-admin(a)classiccmp.org [mailto:cctalk-admin@classiccmp.org]
On Behalf Of Tony Duell
Sent: Thursday, December 05, 2002 6:44 PM
To: cctalk(a)classiccmp.org
Subject: Re: Need information on TRSDOS 1.3 internals
Each track had 10 sectors. They were allocated to
files in groups of
five, which were called granules or grans. There's a Granule
Allocation
Table (GAT) which I think was basically an allocation
bitmap.
TRS-DOS 1.3 ran on the model 3 which used double density (MFM)
recording.
IIRC, there are 18 sectors per track, and 6 sectors per granule (I think
it's 6, not 9).
The GAT is much the same on all versions of TRS-DOS, as is the HIT (Hash
Index Table -- which relates a hashed form of a filename to the
directory
entry that contaisn the info for that file).
-tony