PDP-11 Freeware CD's under emulators

From: Jerome Fine <jhfine_at_idirect.com>
Date: Sat Nov 20 08:46:06 1999

>CLASSICCMP_at_trailing-edge.com wrote:

> >Zane wrote:
> >Of course it would be nice to mount the RT-11 Hobbyist software CD on a
> >emulator running the Hobbyist RT-11, and without MSCP, I don't believe that
> >is possible.
> The best way to do this is with John Wilson's full E11, where you can
> directly mount the high (RT-11 disk structure) partitions of the CD-ROM.
> Of course, this requires the commercial version of E11 for large disk
> MSCP support, and also requires a regular (non-hobbyist) RT-11 license
> to run (as the hobbyist RT-11 license is only good on the Supnik emulator.)
> I think it also requires a SCSI CD-ROM (though I could be wrong and
> it'll work fine with an IDE CD-ROM.)

Jerome Fine replies:

I understand that "Full" E11 V2.1A allows an IDE CD-ROM to be:
"MOUNT DU0: CDROME:"
but I have yet to try and verify that on my PC system under W95.
The probable difficulty with the hobby version of E11 for V2.1A
is that even if the above command might work, the restriction on
having a device of more than 32 MBytes would prevent that from
being done in the hobby version. Eventually, John Wilson may place
that option in PUTR along with the "/PART=n" option which will
allow individual RT-11 partitions to become available which is what
the option in PUTR now allows (if I remember correctly):
"MOUNT DU0: SCSIn:/PART=p"
but of course, the interface must be SCSI, not IDE. If anyone needs
this checked out, I have an Iomega SCSI Zip Drive on the PC which
I don't use much right now (the old 100 MByte version called the
SCSI Insider). And I have just acquired a SCSI CD-ROM drive which
I hope to also test by the end of the year. If anyone has an interest in the
outcome, let me know.

> The next best way to do this is free, and doesn't require commercial
> anything, just the Supnik emulator running on your system and a copy
> of RT-11 in compliance with the hobbyist license. If you look in the
> RT-11 freeware CD at the ISO9660 partition, you'll see that each and
> every piece of software on the CD is represented as a logical .DSK
> file. In particular, in the /dsk directory, you'll find 185 logical
> disks of freeware, split up between the SIGtapes, the DECUS 11-xxx
> entries, and the "other" stuff. These can be mounted as any sort of volume you
> like under the Supnik emulator, as long as the emulated device is
> large enough to hold the contents of the .DSK (i.e. you can use an
> emulated RL02 to hold any virtual .DSK up to 20480 block.) Then
> you're home free, and have "direct" access under the emulator to all
> the contents.

Of course, this method can also be done on the E11 hobby version with
files up the 65535 blocks since V2.1 of the hobby emulator allows:
"MOUNT DU0: E:\DSK\SIGTAPES\11S076.DSK"
as an example - or so I have been told - I have not tried it as yet.
Likewise, PUTR can also MOUNT the files and splits then apart if
they are SIG tapes. Using PUTR is probably entirely legal all the
time since the code is only being copied, not "used". It would not be
legal to use even the hobby version of E11 with even V5.3 of RT-11
which is a hobby version of RT-11 under the Mentec license that
allows ONLY a DEC emulator to be used with V5.3 of RT-11
(usually the Supnik emulator although the Viking emulator for the
Alpha - now discontinued I understand - would also qualify).
So the E11 hobby version of the emulator could also be used to
just split apart very large SIG tapes - I don't know if that would
be considered legal to just pull portions of the SIG tape out on
the assumption that E11 was being used just as PUTR - not to
USE the file, but just to place the portion of the SIG tape into
a file that was small enough to be accessed by the Supnik emulator.

Perhaps Tim Shoppa or Megan Gentry could comment on the
legality of using PUTR to split apart SIG tapes into their smaller
DSK files.

Sincerely yours,

Jerome Fine
Received on Sat Nov 20 1999 - 08:46:06 GMT