cw2dmk 1.6: now does RX02 also

From: Jerome Fine <>
Date: Thu Jun 14 20:03:09 2001

> wrote:

> I've updated the cw2dmk program to version 1.6. This is a program that
> uses the Catweasel ISA disk controller to read disk formats that are hard
> or impossible to read with an ordinary PC floppy disk controller. The
> new version adds a few features, among them the ability to read the DEC
> RX02 double density format. See

Jerome Fine replies:

When you mentioned the Catweasel ISA disk controller and compared it to an
ordinary PC floppy disk controller, it sounds like you are suggesting that
it can run on an ordinary PC? Am I correct in this assumption? If so,
is a special driver also required or does the cw2dmk program do everything?
Also, a rather important question, which floppy drive is used?

I understand that no ordinary PC floppy disk controller/drive drive is able to
read/write the DEC RX02 "double density format" since it is really only a
single density header followed by double density data - or something similar.
It is my understanding that there were third party Qbus controllers which
used Calcomp 8" floppy drives and that even the DEC RX02 controller
could use the Calcomp drive and be double sided. Is that possible with
the cw2dmk program, namely is an 8" RX03 double-density double-sided
(DSDD) floppy possible?

> Source code is included under the GPL, so those who prefer to build their
> own hardware instead of buying a Catweasel (let's not start *that* debate
> again) may find it of some use too.

Since I am not a hardware type, where can I find the Catweasel controller and
a floppy drive so I can read 8" floppy RX02 diskettes on the PC - assuming
that my understanding is correct? And please also help with my question as
to DSDD floppies since more than half of my 8" floppies are DSDD - I used
a DSD 880/30 (Data Systems Design) system on my PDP-11 Qbus system
and modified the driver under RT-11 to also use the other side of the floppy
in the DYX.SYS device driver as well as adding a bounce buffer so that DYX.SYS
could be used under the 22 bit address range of the V5.0x versions of RT-11.

Thanks in advance for any help. I use the PC that I have available to me most of
the time now when I run RT-11, so being able to access the 8" floppies would be
a big plus if this is possible.

Sincerely yours,

Jerome Fine
Received on Thu Jun 14 2001 - 20:03:09 BST

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