Date: Thu, 8 Jun 2000 09:13:02 +0200 (MET DST)
From: Johnny Billquist <bqt@Update.UU.SE>
To: Roger Ivie <rivie@teraglobal.com>
cc: pups@minnie.cs.adfa.edu.au
Subject: Re: RQDX3 software interleave
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On Wed, 7 Jun 2000, Roger Ivie wrote:

> > Speaking of PITA
> >device control, wasn't it the DEC RX02 that wrote address information in
> >single density and data in DD?
> 
> Yes, it was. But it was usually done by the hardware (I suppose that
> would be microcode in the case of the RX02), so unless you wanted to
> do something foolish like read RX02 diskettes in your DD CP/M machine
> or format floppies you don't have to worry about it.

And in those cases, you loose as well. The RX02 uses a micro-engine to
control the drive. No chip controller can switch density in the middle of
the track, so RX02 floppies will forever be in the domain of RX02 drives
only.

Note that formatting RX02 floppes is no problem, since you format them in
single density. The RX02 sets a bit in the header if the data is DD, and
this is controllable from all DEC OSes that I know of.

	Johnny

Johnny Billquist                  || "I'm on a bus
                                  ||  on a psychedelic trip
email: bqt@update.uu.se           ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol