RT11 Freeware Collection

Kenneth Gober kgober at gmail.com
Fri Apr 29 15:11:31 CDT 2022


On Wed, Apr 27, 2022 at 10:55 AM Douglas Taylor via cctech <
cctech at classiccmp.org> wrote:

> I wanted to extract some parts of the RT11 Freeware iso file that is
> available on the internet.  The note Tom Shoppa wrote indicates that the
> CD has 2 partitions.  When I burned the CD on a windows machine I only
> see one partition.
>
> How to I extract the 2nd partition off the iso?
>

The second "partition" is just a second copy of all the files on the first
partition,
except in RT-11 volume format so that it can be mounted directly on an RT-11
system with a CD-ROM drive attached.  Since RT-11 volumes are limited to
32MB, larger disks are broken up into 32MB 'logical disks'.  The files are
on
logical disks 13 through 19 (i.e. 32MB chunk numbers 13 through 19).

Since it's all the same files, there's little reason to bother looking at
the second
partition if you are able to mount the first.  However, if you want to do
it anyway
I have a Windows command-line tool that can be used to access the RT-11
portions of the iso:
GitHub - kgober/FSX: File System Exchange, a utility to access data stored
in disk images <https://github.com/kgober/FSX>

Here are the FSX commands you would use to mount each of the chunks:
FSX> mount r13: rt11freewarev2.iso.gz <skip=416m>
FSX> mount r14: rt11freewarev2.iso.gz <skip=448m>
FSX> mount r15: rt11freewarev2.iso.gz <skip=480m>
FSX> mount r16: rt11freewarev2.iso.gz <skip=512m>
FSX> mount r17: rt11freewarev2.iso.gz <skip=544m>
FSX> mount r18: rt11freewarev2.iso.gz <skip=576m>
FSX> mount r19: rt11freewarev2.iso.gz <skip=608m>

FSX knows about .gz files and will treat the 'skip' option as the offset to
use *after* uncompressing the file.

You can then browse and extract files from each volume:
FSX> dir r19:
 29-Apr-2022
 System ID: DECVMSEXCHNG V41
 Volume ID: VMS Exchange
 Owner    : SHOPPA
README.TXT    23P 15-Oct-1999    TORS84.DSK 24535P 15-Oct-1999
UCLPLS.DSK   907P 15-Oct-1999    VMSBCK.DSK  1663P 15-Oct-1999
XASSMB.DSK  2036P 15-Oct-1999    DUSTAT.DSK   100P 15-Oct-1999
RT11  .LIS    13P 15-Oct-1999    < UNUSED > 36190
 7 Files, 29277 Blocks
 36190 Free blocks

FSX>type r19:readme.txt
Welcome, RT-11 User, to V2.0 of the RT-11 Freeware CD!
[... remainder removed ...]

FSX>save r19:readme.txt c:readme.txt
R19:README.TXT => c:readme.txt

-ken


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