Need information on TRSDOS 1.3 internals

From: Eric Smith <eric_at_brouhaha.com>
Date: Wed Dec 4 21:54:01 2002

Sellam asks:
> Does anyone have any documentation on the data structures of TRSDOS 1.3?
> Specifically, I'd like to know the catalog structure, as well as the
> scheme for storing files across multiple sectors.

I think you want _TRS-80 Disk and Other Mysteries_. That was one of
the Mysteries books I didn't have, but ISTR that Al turned up a copy
recently.

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.

In other DOSes for the TRS-80, which had support for higher-capacity
disks, the number of sectors per granule was often different.

Eric
Received on Wed Dec 04 2002 - 21:54:01 GMT