DEC Pro 3xx archives

Warner Losh imp at
Thu Jan 21 22:20:51 CST 2021

Hey Paul...

This is really helpful. I've had to deal with those archives for the
Rainbow stuff I do and have some additional caveats below I thought I'd

On Thu, Jan 21, 2021, 6:43 PM Paul Koning via cctalk <cctalk at>

> I recently ran into an archive of various Pro 300 items, mostly from DECUS
> I believe.  That includes a full P/OS 3.2 distribution including (!)
> DECnet/Pro if I saw that right.
> It's at
> What makes things somewhat painful is that it's LHA compressed Teledisk
> images, which is an ancient DOS based floppy imaging tool.  The
> instructions say to run Teledisk on a DOS system with a 5.25 inch floppy
> drive to write the images to RX50 floppies, which can then be used.

Those instructions are dated. These days the cool kids use imagedisk to
convert the teledisks to imd format. Usually in dosbox...  or they use unix
variants of these...

The real pain is that the lha has evolved since then and some of the lha
archives there use methods libarchive won't grok...

If you don't have DOS handy, or would rather get floppy image files for use
> with Xhomer, this can work but it's a bit painful.
> I found there's a simpler way.
> 1. Decompress the LHA files.  On a Mac, the unarchiver (I think that comes
> with the OS?) handles that format. On other operating systems, I assume
> it's equally straightforward to find a tool that handles this.  You now
> have a pile of *.TD0 files, which are the TeleDisk format files.

Some, but not all the archives..  macos uses libarchive under the covers.
Most of the td0 I've found decompress, but archive with smaller files are

2. From install LibDsk 1.5 (not 1.4).

This package is good, though there is also a smaller wteledisk that
converts to sector images.

3. Use the dsktrans tool you got from step 2 to convert each *.TD0 file to
> a raw image, like this:
>     dsktrans  -otype raw PRO177/177-21.TD0 proinstallv32.dsk
>    "raw" format means a straight sector dump in physical order; this is
> the format expected by xHomer.

Yea. I'm using this to convert td0 files to imd files...

If for any reason you want a logical order image, for example to give to
> the SIMH "rq" device that emulates an RQDXn controller, you'll need a tool
> that reorders things.  I have one in my RSTS file system tool "flx" (V3 in
> Python, not the earlier 2.6 in C), "".  I can supply more details if
> needed.

I have a c program that does physical to logical and vive versa for the
rainbow, as well as optionally putting the PBP at the front of the disk so
mtools groks the images (though you'd want to do this with a copy)...
though the pro never really had much support for msdos floppies...

All of these formats are understood by MESS's rainbow driver...



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