flash (or ide) storage for unibus 11?

Johnny Billquist bqt at update.uu.se
Tue Nov 24 16:02:40 CST 2015

On 2015-11-24 16:35, Al Kossow wrote:
> On 11/23/15 11:46 PM, Johnny Billquist wrote:
>> Your native interface have the additional problem that in addition to
>> requiring people to write their own device driver for any OS usage, it
>> will be rather difficult to get booting from it, since that
>> require special support.
> There is no reason you can't have two simulated controllers, one small
> enough and early enough to boot a range of operating systems (RL02?), then
> another which exports a simple block-level interface which would be
> simple enough to easily write drivers against.

True. But having your system on an RL02 is still no fun. It's a rather 
small disk, which cause some headache for larger systems.

> RL02 is also interesting because there was a 22 bit version for qbus.

That's one definition of "interesting". :-)

> I'm trying to remember if DSD had extended block length or partioning
> for their controllers.

Not sure about it, but what I normally observed was that 3rd party 
controllers using large disks for some DEC disk usually put several 
logical disks on one physical disk. You could call that partitioning.


Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol

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