Archiving 8" RT-11 floppies to CD-ROM?

Ian King IanK at
Tue Feb 24 13:57:30 CST 2009

I've developed a procedure for this.  It's a bit roundabout but it uses easily available tools.

Tools needed:
- PDP-11 running RT-11, with an extra serial line (SLUx)
- DOS PC with a serial port
- PUTR program from John Wilson
- TU58 emulator, which I found through Will Kranz' website

At a high level the process looks like this:

Install TU58 per its README file.  Copy the contents of the floppy onto the emulated TU58 using the COPY/DEVICE command in RT-11.  Some versions will gripe at you about the fact that the floppy may be bigger than the tape.  RT-11 v4 seems perfectly happy with that, and the TU58 program doesn't care.  :-)  IIRC there are prompts from RT-11 v5, but you can provide answers that will direct it to do the full copy anyway.

Use PUTR to copy from that tape image onto... whatever you want!  PUTR will let you manipulate the individual files and copy them into DOS directories if you so choose.  By using COPY/DEVICE, you can preserve "bootability" of bootable disks, as well.

I've used the reverse of this process to create physical floppies from disk images as well as to restore floppies after disk failures.  Of course, if you want to burn either the images or the individual files onto a CDROM, you'll have to have the files on a machine that supports that device, has burner software, etc.  But at that point, they're just files in a DOS filesystem.

Cheers -- Ian

> -----Original Message-----
> From: cctalk-bounces at [mailto:cctalk-
> bounces at] On Behalf Of Jan-Benedict Glaw
> Sent: Tuesday, February 24, 2009 11:37 AM
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: Re: Archiving 8" RT-11 floppies to CD-ROM?
> On Tue, 2009-02-24 13:14:06 -0500, David Betz <dbetz at>
> wrote:
> > I have a friend who has a number (10-20) of 8" RT-11 floppies he
> wants
> > to archive to CD-ROM or some other modern media. Is there anyone in
> > the Boston area (he lives in Medway) who could help with this? I
> > believe these are RX01 media since I think they were created on a
> > PDT-11/150 that I gave away to someone a few years ago. Can anyone
> > here help? What would the fee be for such a service?
> I obviously cannot help, but it would be nice if, once it is done,
> describe the procedure for others.
> Backup is one thing, restoring the image another. A third thing would
> be to use that image on some simulator...
> MfG, JBG
> --
>       Jan-Benedict Glaw      jbglaw at              +49-172-
> 7608481
>  Signature of:
>  the second  :

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