[Simh] disk file format (rk05)

[Bob Supnik]

As Paul said, disks with fixed-length sectors are represented as 
fixed-length, data-only records.

The IBM 7094 and Honeywell 516 disks have variable length records, and 
the track format includes metadata on record lengths and block 
addresses. The IBM 1401 and 1620 disks include metadata for the block 
addresses, which is not necessarily based on geometry.

/Bob Supnik

On 9/25/2018 12:00 PM, simh-request at trailing-edge.com wrote:
> Message: 3
> Date: Tue, 25 Sep 2018 09:53:04 -0400
> From: Paul Koning<paulkoning at comcast.net>
> To: Folkert van Heusden<mail at vanheusden.com>
> Cc:simh at trailing-edge.com
> Subject: Re: [Simh] disk file format (rk05)
> Message-ID:<531AA05C-E3A0-4387-8806-B22269E5E118 at comcast.net>
> Content-Type: text/plain;	charset=us-ascii
>
> Disks are just sectors.  I think that's true generally; if SIMH supported any systems with variable length disk blocks something else would be needed, but the only system I can think of that does so is the IBM 360.  (Actually, that one is much stranger, with its keyed sector feature.)