2 Dec
1999
2 Dec
'99
8:55 a.m.
>I still wonder why. The only thing I can think of
is that either the driver
>for the RC25 was removed or that VMS would no longer fit on an RC25 cartridge
>as a boot volume. The drives used two platters, one fixed, one removable,
>26Mb
Don't know about as a boot disk, but the RC25 is
still supported.
Definitely not for the boot disk. The most basic VMS kit (that is,
without help pages, without libraries, certainly no DECWindows!) for VMS
6.1 won't fit in the 25 Mbytes available in a RC25.
6.2 "officially" requires more than 120 Mbytes for a basic installation,
but if you fool its installation procedure you can shoehorn it onto a
RZ23 (100 Mbytes)
I suspect it was a question of RAM. Looking at the
configurations for the
11/725 and 11/730 it looks as if the 11/730 would hold at least a couple
more MB.
Officially the 730 only holds 5 Mbytes. I don't know if there's any
way of extending this.
Remember also that the RC25, if the "fixed" platter is used as a system
disk, can be spun down to change the removable data platter. The host
OS needs to be aware that its system disk might be spun down, and it has
to be patient enough to wait for it to come back up. The PDP-11 OS's know
how to do this, and the last version of VMS to officially support the
725 with RC25 knows how to do this, but I don't know if they included
support for this in the more modern versions of VMS.
My 11/730, when I had it, ran VMS 4.6.
I'm wondering if it wouldn't be possible to
replace the RC25 with a 3rd
Party SCSI controller. Though I'm not aware of any 11/725's in anyones
collection.
I know of a 11/725 still running a monitoring/logging application at a
nuclear power plant, booting from a RC25 under VMS 4.2. And yes, they
could upgrade to a SCSI drive and Unibus SCSI host adapter.
--
Tim Shoppa Email: shoppa(a)trailing-edge.com
Trailing Edge Technology WWW: http://www.trailing-edge.com/
7328 Bradley Blvd Voice: 301-767-5917
Bethesda, MD, USA 20817 Fax: 301-767-5927
2 Dec
2 Dec
9:17 a.m.
Definitely not for the boot disk. The most basic VMS
kit (that is,
without help pages, without libraries, certainly no DECWindows!) for VMS
6.1 won't fit in the 25 Mbytes available in a RC25.
The last version that would fit on that had to be before V5!
I suspect it
was a question of RAM. Looking at the configurations for the
11/725 and 11/730 it looks as if the 11/730 would hold at least a couple
more MB.
Officially the 730 only holds 5 Mbytes. I don't know if there's any
way of extending this. how to do this, and the last version of VMS to
officially support the
725 with RC25 knows how to do this, but I don't know if they included
support for this in the more modern versions of VMS.
As of V5.5-4 it did.
Allison
1:33 p.m.
>>I still wonder why. The only thing I can
think of is that either the driver
>>for the RC25 was removed or that VMS would no longer fit on an RC25 cartridge
>>as a boot volume. The drives used two platters, one fixed, one removable,
>>26Mb
Hope its not bad form to try to give something away in the midst of a discussion,
but I find all this talk of the RC25 as an opportunity to get rid of one that has
been taking up shelf space here. Anyone willing to pay shipping on it can contact
me off list (it is HEAVY). Especially if someone in the Houston area can come pick
it up and save me hastle of packaging it.
This came out of a surplus sale many years ago. I've never been able to find a
power supply/enclosure for it, so condition unknown. One pack also included.
Nick
8994
days inactive
8994
days old
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