[Unix-jun72] rk03 vs rk05

[Unix-jun72] rk03 vs rk05

[James A. Markevitch]

> Confusingly, the 1e manual for /dev/rk0 says its an RK03. I'll have to go
> read the DEC manuals, but I would guess that the RK11 drive and interface is
> the same, but the RK03 and RK05 removable disk packs were of different
> storage capacity.

The controller is an RK11.
The disk drives are RK02, RK03, RK05.

The RK02 is a 1.2MB drive (256B per sector).
The RK03 is a 2.4MB drive (512B per sector).
The RK05 is a 2.4MB drive (512B per sector).

The media for the RK03 and RK05 are compatible (IBM 2315).  The drives
look different from each other, but I don't think the system can tell
the difference.

James Markevitch

[Unix-jun72] rk03 vs rk05

[Wilko Bulte]

Quoting James A. Markevitch, who wrote on Sat, May 03, 2008 at 06:59:44PM -0700 ..
> > Confusingly, the 1e manual for /dev/rk0 says its an RK03. I'll have to go
> > read the DEC manuals, but I would guess that the RK11 drive and interface is
> > the same, but the RK03 and RK05 removable disk packs were of different
> > storage capacity.
> 
> The controller is an RK11.
> The disk drives are RK02, RK03, RK05.
> 
> The RK02 is a 1.2MB drive (256B per sector).
> The RK03 is a 2.4MB drive (512B per sector).
> The RK05 is a 2.4MB drive (512B per sector).

There was also a RK05F which used a fixed platter (in the same
plastic enclosure as the removables if I remember correctly).  That was
double capacity, around 5MB.

Wilko

[Unix-jun72] rk03 vs rk05

[James A. Markevitch]

> > The controller is an RK11.
> > The disk drives are RK02, RK03, RK05.
> > 
> > The RK02 is a 1.2MB drive (256B per sector).
> > The RK03 is a 2.4MB drive (512B per sector).
> > The RK05 is a 2.4MB drive (512B per sector).
> 
> There was also a RK05F which used a fixed platter (in the same
> plastic enclosure as the removables if I remember correctly).  That was
> double capacity, around 5MB.

Yes, the RK05J is the removable one, as described above.  The RK05F is
the fixed version that doubles the density.  However, to the system, it
appears as two separate drives, not as a single 5MB drive.  I am not
sure how the data were interleaved between the two "logical drives"
which is important when scheduling seeks on the logical drives.

James Markevitch

[Unix-jun72] rk03 vs rk05

[Warren Toomey]

On Sat, May 03, 2008 at 08:16:23AM -1000, Tim Newsham wrote:
> > We may not need mount afterall.  The init process mounts /dev/rk0 on
> > /usr during startup (after the second "1:" label on e12-01).
> 
> Oh, for what its worth, the init sources say its an "rk05" disk ("rko5" 
> actually ;-) I think Warren was asking about which model to use earlier.

Confusingly, the 1e manual for /dev/rk0 says its an RK03. I'll have to go
read the DEC manuals, but I would guess that the RK11 drive and interface is
the same, but the RK03 and RK05 removable disk packs were of different
storage capacity.

	Warren