Multi-platform distribution format (Was: Backups [was

[tony duell]

[Russian PDP11-a-like]

> 
> I've tried to boot an RX01 Floppy in RX02 mode, that failed on all disks
> I've tried. Is an original RX02 able to boot (RT11) from an RX01 disk?

As far as I know, it can't. An RX02 can read/write an RX01 disk, but the software
interface to the controller is so different (the RX)2 uses DMA, the RX01 doesn't for
one thing) that the RX02 cannot boot an RX01 disk.

> I know that a different device driver has to be used  normally, but I had
> no RX02 media and wasn't able to make one, since the machine has no other
> drives connected and the card cage is mechanically not compatible (metric
> dimensions including the fingers).
> I know that in the RX02 Mode the Drive has an format track command that
> doesn't exist in RX01 mode, that's documented. How about the RX02?

The RX02 has a 'set density' command that can be used to reformat a 
formatted single density disk as double density.

> Is there somewhere a picture from the Conteroller PCB of the DEC RX02
> (just to look at). The russian controller has a 2910 and four 2901 if
> I remember correctly... (K1804VU1 and 4xK1804VS1)

The RX02 drive contains a couple of 2901s and a few of the sequencer chips
(I think 2911s, maybe 2909s). I've seen a 3rd party Qbus card that connected to
normal Shugart drives and which could red/write RX02 disks, I think that had 
a couple of 2901s and a 2910 on it.

-tony